Sustainable U.S. Marine Aquaculture Expansion in the 21st Century
Sustainable U.S. Marine Aquaculture Expansion in the 21st Century
Sustainable U.S. Marine Aquaculture Expansion in the 21st Century
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Journal<br />
The International, Inderdiscipl<strong>in</strong>ary Society Devoted to Ocean and <strong>Mar<strong>in</strong>e</strong> Eng<strong>in</strong>eer<strong>in</strong>g, Science, and Policy<br />
Volume 44 Number 3 May/June 2010<br />
<strong>Susta<strong>in</strong>able</strong> U.S. <strong>Mar<strong>in</strong>e</strong><br />
<strong>Aquaculture</strong> <strong>Expansion</strong><br />
<strong>in</strong> <strong>the</strong> 21 st <strong>Century</strong>
<strong>Mar<strong>in</strong>e</strong> Technology Society Officers<br />
BOA RD OF DIREC T ORS<br />
President<br />
Elizabeth Corb<strong>in</strong><br />
Hawaii, Department of Bus<strong>in</strong>ess, Economic<br />
Development and Tourism<br />
President-elect<br />
Jerry Boatman<br />
Plann<strong>in</strong>g Systems, Inc.<br />
Immediate Past President<br />
Bruce C. Gilman, P.E.<br />
Consultant<br />
VP—Section Affairs<br />
Kev<strong>in</strong> Hardy<br />
DeepSea Power and Light<br />
VP—Education and Research<br />
Jill Zande<br />
MATE Center<br />
VP—Industry and Technology<br />
Jerry C. Wilson<br />
Fugro Pelagos, Inc.<br />
VP—Publications<br />
Kar<strong>in</strong> Lynn<br />
Treasurer and VP—Budget and F<strong>in</strong>ance<br />
Debra Kill<br />
International Submar<strong>in</strong>e Eng<strong>in</strong>eer<strong>in</strong>g<br />
VP—Government and Public Affairs<br />
Just<strong>in</strong> Manley<br />
Liquid Robotics<br />
SEC T IONS<br />
Canadian Maritime<br />
Vacant<br />
Florida<br />
Prof. Mark Lu<strong>the</strong>r<br />
University of South Florida<br />
Gulf Coast<br />
Ted Bennett<br />
Naval Oceanographic Office<br />
Hampton Roads<br />
Raymond Toll<br />
SAIC<br />
Hawaii<br />
Philomene Verlaan, Ph.D., J.D.<br />
Houston<br />
Marcy A. Whites<br />
Oil States Industries, Inc.<br />
Japan<br />
Prof. Toshitsugu Sakou<br />
Tokai University<br />
Monterey<br />
Jill Zande<br />
MATE<br />
New England<br />
Chris Jakubiak<br />
UMASS Dartmouth-SMAST<br />
Newfoundland and Labrador<br />
Bill O’Keefe<br />
Surmount Technologies, Inc.<br />
Puget Sound<br />
Fritz Stahr<br />
University of Wash<strong>in</strong>gton<br />
San Diego<br />
Barbara Fletcher<br />
SSC-San Diego<br />
South Korea<br />
Dr. Seok Won Hong<br />
Maritime & Ocean Eng<strong>in</strong>eer<strong>in</strong>g Research Inst.<br />
(MOERI/KORDI)<br />
Wash<strong>in</strong>gton, D.C.<br />
Robert (Rusty) Mirick<br />
Booz Allen Hamilton<br />
P ROF E S SION A L COMMI T T EES<br />
Industry and Technology<br />
Buoy Technology<br />
Dr. Walter Paul<br />
Woods Hole Oceanographic Institution<br />
Cables and Connectors<br />
Helmut H. Portmann<br />
National Data Buoy Center<br />
Deepwater Field Development Technology<br />
Dr. Benton Baugh<br />
Radoil, Inc.<br />
Div<strong>in</strong>g<br />
David C. Berry<br />
Subsea Construction and Div<strong>in</strong>g Consultant<br />
Dynamic Position<strong>in</strong>g<br />
Howard Shatto<br />
Shatto Eng<strong>in</strong>eer<strong>in</strong>g<br />
Manned Underwater Vehicles<br />
William Kohnen<br />
SEAmag<strong>in</strong>e Hydrospace Corporation<br />
Moor<strong>in</strong>gs<br />
Jack Rowley, SAIC<br />
Oceanographic Instrumentation<br />
Dr. Jim Irish<br />
University of New Hampshire<br />
Offshore Structures<br />
Dr. Peter W. Marshall<br />
MHP Systems Eng<strong>in</strong>eer<strong>in</strong>g<br />
Remotely Operated Vehicles<br />
Drew Michel<br />
ROV Technologies, Inc.<br />
Renewable Energy<br />
Rich Chwaszczewski<br />
Ropes and Tension Members<br />
Evan Zimmerman<br />
Delmar Systems<br />
Seafloor Eng<strong>in</strong>eer<strong>in</strong>g<br />
Herb Herrmann<br />
Naval Seafloor Cable Protection Office<br />
Underwater Imag<strong>in</strong>g<br />
Dr. Fraser Dalgleish<br />
Harbor Branch Oceanographic Institute<br />
Unmanned Maritime Vehicles<br />
Just<strong>in</strong> Manley<br />
Liquid Robotics<br />
Education and Research<br />
<strong>Mar<strong>in</strong>e</strong> Archaeology<br />
Brett Phaneuf<br />
ProMare, Inc.<br />
<strong>Mar<strong>in</strong>e</strong> Education<br />
Dr. Susan B. Cook<br />
Consortium for Ocean Leadership<br />
<strong>Mar<strong>in</strong>e</strong> Geodetic Information Systems<br />
Dave Zilkoski<br />
NOAA<br />
<strong>Mar<strong>in</strong>e</strong> Materials<br />
Vacant<br />
Ocean Exploration<br />
Vacant<br />
Physical Oceanography/Meteorology<br />
Dr. Richard L. Crout<br />
National Data Buoy Center<br />
Remote Sens<strong>in</strong>g<br />
Herb Ripley<br />
Hyperspectral Imag<strong>in</strong>g Limited<br />
Government and Public Affairs<br />
<strong>Mar<strong>in</strong>e</strong> Law and Policy<br />
Montserrat Gor<strong>in</strong>a-Ysern<br />
Healthy Children–Healthy Oceans Foundation<br />
<strong>Mar<strong>in</strong>e</strong> M<strong>in</strong>eral Resources<br />
Dr. John C. Wiltshire<br />
University of Hawaii<br />
<strong>Mar<strong>in</strong>e</strong> Security<br />
Dallas Meggitt<br />
Sound & Sea Technology<br />
Ocean Economic Potential<br />
James Marsh<br />
University of Hawaii<br />
Ocean Observ<strong>in</strong>g Systems<br />
Donna Kocak<br />
Maritime Communication Systems,<br />
HARRIS Corporation<br />
Ocean Pollution<br />
Jacob Sob<strong>in</strong><br />
S T UDENT SEC T IONS<br />
Duke University<br />
Counselor: Douglas Nowacek, Ph.D.<br />
Florida Atlantic University<br />
Counselor: Douglas A. Briggs, Ph.D.<br />
Florida Institute of Technology<br />
Counselor: Stephen Wood, Ph.D., P.E.<br />
Long Beach City College<br />
Counselor: Scott Fraser<br />
Massachusetts Institute of Technology<br />
Counselor: Alexandra Techet, Ph.D.<br />
Monterey Pen<strong>in</strong>sula College<br />
Counselor: Jeremy R. Hertzberg<br />
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Counselor: Patrick Lynett<br />
Texas A&M University—Galveston<br />
Counselor: Frank Warnakula<br />
University of Hawaii<br />
Counselor: Reza Ghorbani<br />
University of Houston<br />
Counselors: Raresh Pascali, Chuck Richards<br />
University of North Carol<strong>in</strong>a—Charlotte<br />
Counselor: James Conrad<br />
University of Sou<strong>the</strong>rn Mississippi<br />
Counselor: Stephen Howden, Ph.D.<br />
Webb Institute<br />
Counselor: Mat<strong>the</strong>w Werner<br />
HONOR A RY MEMBERS<br />
†Robert B. Abel<br />
†Charles H. Bussmann<br />
John C. Calhoun, Jr.<br />
John P. Craven<br />
†Paul M. Fye<br />
David S. Potter<br />
†A<strong>the</strong>lstan Spilhaus<br />
†E. C. Stephan<br />
†Allyn C. V<strong>in</strong>e<br />
†James H. Wakel<strong>in</strong>, Jr.<br />
†deceased
Front Cover: SeaStation Net Pen, photo courtesy of<br />
OceanSpar LLC.<br />
Back Cover: (l-r) Top row: Mature mussels at 15m depth;<br />
Five-tiered lantern net used for open water oyster culture<br />
(see Cheney et al. paper); New Aquapod cage design<br />
be<strong>in</strong>g outfitted for deployment (photo courtesy<br />
Barry Costa-Pierce). Middle row: Moi harvest (photo courtesy<br />
Cates International, Inc.); Upper section of scallop spar<br />
at deployment <strong>in</strong> surface mode (see Cheney et al. paper);<br />
20-ton capacity multi-cage feeder developed by <strong>the</strong><br />
University of New Hampshire (UNH), Ocean Spar and <strong>the</strong><br />
<strong>Aquaculture</strong> Eng<strong>in</strong>eer<strong>in</strong>g Group (see Langan paper). Bottom<br />
row: Small offshore cage with copper alloy nett<strong>in</strong>g after a<br />
120-day deployment at <strong>the</strong> UNH experimental offshore<br />
site (see Langan paper); SeaStation cage be<strong>in</strong>g outfitted<br />
for submerged deployment off New Hampshire (photo<br />
courtesy Richard Langan); diver us<strong>in</strong>g a hydraulic net<br />
cleaner on a SeaStation cage <strong>in</strong>stalled at Keahole Po<strong>in</strong>t<br />
(see Loverich paper).<br />
Text: SPi<br />
Cover and Graphics:<br />
Michele A. Danoff, Graphics By Design<br />
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In This Issue<br />
3<br />
<strong>Susta<strong>in</strong>able</strong> U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
In <strong>the</strong> <strong>21st</strong> <strong>Century</strong><br />
Foreword by John S. Corb<strong>in</strong><br />
7<br />
<strong>Susta<strong>in</strong>able</strong> U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
<strong>Expansion</strong>, a Necessity<br />
John S. Corb<strong>in</strong><br />
22<br />
Site Selection Criteria for Open<br />
Ocean <strong>Aquaculture</strong><br />
Daniel D. Benetti, Gabriel I. Benetti,<br />
José A. Rivera, Bruno Sardenberg,<br />
Brian O’Hanlon<br />
36<br />
A Case Study of an Offshore SeaStation ®<br />
Sea Farm<br />
Gary F. Loverich<br />
47<br />
Technology Needs for Improved<br />
Operational Efficiency of Open Ocean<br />
Cage Culture<br />
Richard Langan<br />
55<br />
Shellfish Culture <strong>in</strong> <strong>the</strong> Open Ocean:<br />
Lessons Learned for Offshore <strong>Expansion</strong><br />
Daniel Cheney, Richard Langan,<br />
Kev<strong>in</strong> Heasman, Bernard Friedman,<br />
Jonathan Davis<br />
Volume 44, Number 3, May/June 2010<br />
<strong>Susta<strong>in</strong>able</strong> U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
<strong>Expansion</strong> <strong>in</strong> <strong>the</strong> <strong>21st</strong> <strong>Century</strong><br />
Guest Editor: John S. Corb<strong>in</strong><br />
68<br />
What Can U.S. Open Ocean<br />
<strong>Aquaculture</strong> Learn From<br />
Salmon Farm<strong>in</strong>g?<br />
John Forster<br />
80<br />
Deep Ocean Water Resources <strong>in</strong> <strong>the</strong><br />
<strong>21st</strong> <strong>Century</strong><br />
Brandon A. Yoza, Gérard C. Nihous,<br />
Patrick. K. Takahashi, Lars G. Golmen,<br />
Jan C. War, Koji Otsuka,<br />
Kazuyuki Ouchi, Stephen M. Masutani<br />
88<br />
<strong>Susta<strong>in</strong>able</strong> Ecological <strong>Aquaculture</strong><br />
Systems: The Need for a New Social<br />
Contract for <strong>Aquaculture</strong> Development<br />
Barry A. Costa-Pierce<br />
113<br />
<strong>Mar<strong>in</strong>e</strong> Stock Enhancement, a<br />
Valuable Extension of Expanded<br />
U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
Commentary by John S. Corb<strong>in</strong><br />
119<br />
U.S. Open Ocean Fish Farm<strong>in</strong>g: Are We<br />
There Yet?<br />
Randy Cates
Editorial Board<br />
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FOREWORD<br />
<strong>Susta<strong>in</strong>able</strong> U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
In <strong>the</strong> <strong>21st</strong> <strong>Century</strong><br />
John S. Corb<strong>in</strong><br />
Guest Editor<br />
President<br />
<strong>Aquaculture</strong> Plann<strong>in</strong>g & Advocacy LLC<br />
In his 1957 book, The Deep Range, <strong>the</strong> famed science fiction writer, Arthur C. Clarke,<br />
described <strong>the</strong> ocean ranch<strong>in</strong>g of whales and <strong>the</strong> farm<strong>in</strong>g of plankton to feed <strong>the</strong> whales and<br />
a world population dependent on <strong>the</strong> ocean for food, 100 years <strong>in</strong> <strong>the</strong> future.<br />
The ocean explorer Jacques Cousteau op<strong>in</strong>ed, prior to <strong>the</strong> late 1970s global explosion of<br />
aquaculture technologies, “With earth’s burgeon<strong>in</strong>g human population to feed we must<br />
turn to <strong>the</strong> sea with new understand<strong>in</strong>g and new technology. We need to farm it as we<br />
farm <strong>the</strong> land.”<br />
These <strong>the</strong>n-novel visions of mar<strong>in</strong>e aquaculture have come <strong>in</strong>to sharper focus with <strong>the</strong><br />
passage of time, <strong>the</strong> relentless <strong>in</strong>crease <strong>in</strong> human population, and <strong>the</strong> realization of <strong>the</strong> potential<br />
for global climate change to drastically disrupt food production regions and <strong>the</strong> food<br />
distribution networks <strong>in</strong> an <strong>in</strong>creas<strong>in</strong>gly <strong>in</strong>terconnected and complex world economy.<br />
Today <strong>in</strong> <strong>the</strong> United States, <strong>the</strong> decade-old and at times contentious debate has evolved<br />
over <strong>the</strong> potential and possible perils of aquaculture <strong>in</strong> federal ocean waters for <strong>in</strong>creased<br />
domestic seafood production. Policymakers and stakeholders have shifted from wrangl<strong>in</strong>g<br />
over <strong>the</strong> merits of encourag<strong>in</strong>g open ocean aquaculture at all to active discussion of how<br />
and where it can be carried out us<strong>in</strong>g environmentally susta<strong>in</strong>able technologies, economically<br />
viable bus<strong>in</strong>ess models, socially acceptable practices, and appropriate government<br />
oversight. Many ma<strong>in</strong>stream American seafood and environmental <strong>in</strong>terests have accepted<br />
<strong>the</strong> mount<strong>in</strong>g statistics and trend analyses that demonstrate that <strong>the</strong> world’s capture fisheries<br />
cannot meet society’s <strong>in</strong>creas<strong>in</strong>g demand for seafood and have chosen to work with<br />
aquaculture <strong>in</strong>terests to address development issues. Expert global projections conclude that<br />
aquaculture will become <strong>the</strong> predom<strong>in</strong>ant source of future <strong>in</strong>creases <strong>in</strong> seafood supply,<br />
help<strong>in</strong>g to harmonize capture and culture seafood distribution channels and more widely<br />
improv<strong>in</strong>g <strong>the</strong> livelihoods and diets of developed and develop<strong>in</strong>g countries around <strong>the</strong><br />
world. Will <strong>the</strong> United States be an active participant <strong>in</strong> this “Blue Revolution” or simply<br />
a hungry market for seafood produced by foreign sources?<br />
In sett<strong>in</strong>g <strong>the</strong> stage for <strong>the</strong> expert presentations that follow, it is <strong>in</strong>structive to consider this<br />
publication <strong>in</strong> <strong>the</strong> larger context of <strong>the</strong> U.S. mar<strong>in</strong>e technology <strong>in</strong>dustry and <strong>the</strong> purpose of<br />
May/June 2010 Volume 44 Number 3 3
FOREWORD<br />
<strong>the</strong> <strong>Mar<strong>in</strong>e</strong> Technology Society. The <strong>Mar<strong>in</strong>e</strong> Technology Society’s guid<strong>in</strong>g purpose is, “to<br />
promote awareness, understand<strong>in</strong>g, advancement, and application of mar<strong>in</strong>e technology.”<br />
In this case <strong>the</strong> timely topic is U.S. mar<strong>in</strong>e aquaculture development, with emphasis on <strong>the</strong><br />
status and future of open ocean farm<strong>in</strong>g. Articles <strong>in</strong> this volume largely consider fish and<br />
shellfish species and <strong>the</strong>ir contribution to edible and nonedible fisheries and aquaculture<br />
products. The grow<strong>in</strong>g importance of wild harvest and culture of macroalgae (seaweed) and<br />
microalgae to <strong>the</strong> future of world seafood and energy supplies must be noted; however,<br />
<strong>the</strong>se sources are not primary topics <strong>in</strong> <strong>the</strong>se presentations.<br />
In this special issue, experts <strong>in</strong> <strong>the</strong> field were asked to address key topics and critical<br />
issues concern<strong>in</strong>g mar<strong>in</strong>e aquaculture development, with emphasis on potential for Exclusive<br />
Economic Zone (EEZ) use for susta<strong>in</strong>able farm<strong>in</strong>g. The <strong>the</strong>me of this volume, “<strong>Susta<strong>in</strong>able</strong><br />
U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong> <strong>Expansion</strong> <strong>in</strong> <strong>the</strong> <strong>21st</strong> <strong>Century</strong>,” reflects <strong>the</strong> central<br />
<strong>the</strong>me of <strong>the</strong> recent national dialogue over large-scale farm<strong>in</strong>g of <strong>the</strong> ocean environment.<br />
Broadly, contributors were asked to address <strong>the</strong> follow<strong>in</strong>g: (1) current status of <strong>the</strong> topic or<br />
issue, (2) where <strong>the</strong> aquaculture <strong>in</strong>dustry should go with <strong>the</strong> topic or issue to expand and be<br />
successful <strong>in</strong> 20 years, and (3) major obstacles apparent today and go<strong>in</strong>g forward that require<br />
resolution to make progress. The <strong>in</strong>tended focus is America; however, <strong>in</strong>formation<br />
also has been drawn from global aquaculture development when desirable to establish <strong>the</strong><br />
world context <strong>in</strong> a complex global seafood economy.<br />
The 10 articles <strong>in</strong> this volume discuss a wide range of technical and nontechnical issues<br />
that will guide susta<strong>in</strong>able expansion of U.S. mar<strong>in</strong>e aquaculture, particularly <strong>in</strong> <strong>the</strong> EEZ.<br />
Most authors focus on aspects of <strong>the</strong> science and technology of mar<strong>in</strong>e farm<strong>in</strong>g. O<strong>the</strong>r<br />
contributors elucidate <strong>the</strong> development lessons learned from successful commercial expansion<br />
of salmonid and bivalve culture <strong>in</strong> <strong>the</strong> United States and around <strong>the</strong> world. Still o<strong>the</strong>rs<br />
focus on emerg<strong>in</strong>g <strong>in</strong>dustry development policy and plann<strong>in</strong>g issues impact<strong>in</strong>g how <strong>the</strong><br />
development challenges are approached. Specifically, <strong>the</strong> topics addressed are as follows:<br />
■ Corb<strong>in</strong> <strong>in</strong>troduces <strong>the</strong> special issue and “sets <strong>the</strong> stage” by provid<strong>in</strong>g detailed background<br />
<strong>in</strong>formation on U.S. seafood consumption, supply, and projected needs. The potential for<br />
disruption of seafood imports is considered and <strong>the</strong> huge U.S. ocean resource for development<br />
is reviewed.<br />
■ Benetti et al. address <strong>the</strong> critical issue of suitable sit<strong>in</strong>g of offshore mar<strong>in</strong>e farms. Experience<br />
to date is reviewed, and <strong>the</strong> many important parameters that must be considered<br />
to select optimal sites for susta<strong>in</strong>able, long-term farm management with m<strong>in</strong>imal environmental<br />
impacts are discussed.<br />
■ Loverich provides valuable <strong>in</strong>sights <strong>in</strong>to <strong>the</strong> design and operation of sea cages for<br />
open ocean conditions through a case study of a pioneer<strong>in</strong>g private enterprise that used<br />
commercially available technology. The development of several <strong>in</strong>novative features to<br />
4 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal
FOREWORD<br />
improve operation of sea cages is described, show<strong>in</strong>g <strong>the</strong> value of large-scale commercial<br />
demonstration projects.<br />
■ Langan reviews <strong>the</strong> state of <strong>the</strong> technology for automation of many of <strong>the</strong> critical operational<br />
protocols and procedures <strong>in</strong>volved <strong>in</strong> offshore aquaculture. Cost reduction through<br />
mechanization of such rout<strong>in</strong>e procedures as stock<strong>in</strong>g, feed<strong>in</strong>g, and harvest<strong>in</strong>g is deemed<br />
essential to <strong>the</strong> evolution of large-scale, economically viable open ocean farm<strong>in</strong>g.<br />
■ Cheney et al. review <strong>the</strong> current commercial production of bivalve shellfish (largely<br />
<strong>in</strong>shore), describe various emerg<strong>in</strong>g offshore shellfish culture systems utiliz<strong>in</strong>g case studies,<br />
and assess <strong>the</strong> lessons learned and future potentials of cultur<strong>in</strong>g bivalves at open ocean<br />
locations. Bivalve aquaculture currently is a major producer of edible mar<strong>in</strong>e fishery<br />
products, both <strong>in</strong> <strong>the</strong> United States and around <strong>the</strong> world.<br />
■ Forster provides a detailed review of <strong>the</strong> development of <strong>the</strong> global salmonid (salmon<br />
and salt water trout) <strong>in</strong>dustry, <strong>the</strong> most successful commercial mar<strong>in</strong>e fish farm<strong>in</strong>g activity<br />
<strong>in</strong> <strong>the</strong> world. Important lessons and considerations that address perceived constra<strong>in</strong>ts to<br />
U.S. mar<strong>in</strong>e aquaculture development are described.<br />
■ Yoza et al. consider <strong>the</strong> future of open ocean aquaculture and <strong>the</strong> next generation of<br />
technologies that are beg<strong>in</strong>n<strong>in</strong>g to be conceptualized and tested. Focus is on <strong>in</strong>corporation<br />
of artificial upwell<strong>in</strong>g systems <strong>in</strong>to mar<strong>in</strong>e aquaculture production systems, e.g.,<br />
Ocean Thermal Energy Conversion systems and large-scale platform farms that can be<br />
<strong>in</strong>valuable <strong>in</strong> establish<strong>in</strong>g large-scale mar<strong>in</strong>e farm<strong>in</strong>g <strong>in</strong> <strong>the</strong> far reaches of <strong>the</strong> U.S. EEZ.<br />
■ Costa-Pierce describes ecological aquaculture, an emerg<strong>in</strong>g, new paradigm for global<br />
aquaculture plann<strong>in</strong>g, policy, and development as a broad context for consideration of<br />
U.S. expansion. He argues that policymakers should consider this approach to foster<br />
environmentally, economically, and socially responsible aquaculture. <strong>Aquaculture</strong>’srich<br />
history is briefly described, and <strong>in</strong>tegration of aquaculture <strong>in</strong>to sector plann<strong>in</strong>g for fisheries,<br />
agriculture, and ecosystem conservation and restoration is discussed.<br />
■ Corb<strong>in</strong> provides a brief discussion of <strong>the</strong> history and current status of U.S. mar<strong>in</strong>e stock<br />
enhancement as a valuable tool for coastal fisheries management. Conclusions are drawn<br />
regard<strong>in</strong>g <strong>the</strong> need for <strong>in</strong>creased research fund<strong>in</strong>g, greater <strong>in</strong>frastructure plann<strong>in</strong>g and<br />
development, and <strong>in</strong>clusion of mar<strong>in</strong>e stock enhancement <strong>in</strong> current national ocean policy<br />
and mar<strong>in</strong>e spatial plann<strong>in</strong>g efforts.<br />
■ Cates provides a commercial offshore fish farmer’s hard-won <strong>in</strong>sights on <strong>the</strong> state of <strong>the</strong><br />
technology as well as <strong>the</strong> status of federal support policies and programs. Research needs<br />
and areas for <strong>in</strong>novation are highlighted that could help successfully establish commercial<br />
farm<strong>in</strong>g <strong>in</strong> <strong>the</strong> EEZ.<br />
The recent book, Hot, Flat and Crowded by Tom Friedman, <strong>in</strong>cluded a say<strong>in</strong>g attributed<br />
to a nomadic African tribe, “If you want to go fast, go alone, if you want to go far, go<br />
May/June 2010 Volume 44 Number 3 5
FOREWORD<br />
toge<strong>the</strong>r.” As with <strong>the</strong> history of many mar<strong>in</strong>e technologies <strong>in</strong> widespread use today, successful<br />
and susta<strong>in</strong>able U.S. mar<strong>in</strong>e aquaculture development would be greatly facilitated<br />
by active collaboration with certa<strong>in</strong> of <strong>the</strong> wide variety of technical discipl<strong>in</strong>es and myriad<br />
of companies that make up <strong>the</strong> American mar<strong>in</strong>e technology <strong>in</strong>dustry. Application, <strong>in</strong>novation,<br />
and adoption on <strong>the</strong> basis of established and emerg<strong>in</strong>g technologies could spur<br />
progress <strong>in</strong> farm<strong>in</strong>g <strong>the</strong> open ocean environment, for example, remote sens<strong>in</strong>g, environmental<br />
monitor<strong>in</strong>g <strong>in</strong>strumentation, robotics and unmanned vehicles, deep ocean moor<strong>in</strong>g,<br />
ocean energy generation, and materials handl<strong>in</strong>g systems. It is hoped this volume may help<br />
foster such much needed collaboration.<br />
What will <strong>the</strong> future br<strong>in</strong>g for global and U.S. seafood and its two sources, capture<br />
fisheries and aquaculture? Clearly, <strong>the</strong> world is on an uncerta<strong>in</strong> path toward select<strong>in</strong>g<br />
where and how <strong>the</strong> needed aquatic prote<strong>in</strong> will be produced. Capture fisheries sources<br />
dom<strong>in</strong>ated seafood supply <strong>in</strong> <strong>the</strong> latter part of <strong>the</strong> 20th century, and it appears aquaculture<br />
sources will dom<strong>in</strong>ate supply <strong>in</strong> <strong>the</strong> early <strong>21st</strong> century. Look<strong>in</strong>g <strong>in</strong>to a crystal ball, it is<br />
envisioned that by mid-century, <strong>the</strong>re will be a blurr<strong>in</strong>g of <strong>the</strong> dist<strong>in</strong>ction between capture<br />
and culture fisheries on <strong>the</strong> basis of today’s resource management approaches. More economically<br />
important, mar<strong>in</strong>e fisheries will be supported by hatchery-produced stock, and<br />
<strong>the</strong> deep open ocean will be susta<strong>in</strong>ably farmed and ranched by next generation technologies<br />
that have evolved from <strong>in</strong>dustrial-scale and ecosystem-based aquaculture.<br />
Will this worldwide seafood vision be <strong>in</strong> <strong>the</strong> realm of science fiction or a scientific fact?<br />
For American society and U.S. mar<strong>in</strong>e fisheries and aquaculture <strong>in</strong>terests, <strong>the</strong> answer to this<br />
question largely depends on <strong>in</strong>dustry development and regulatory policy decisions be<strong>in</strong>g<br />
made by Congress and <strong>the</strong> federal government today.<br />
6 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal
PAPER<br />
<strong>Susta<strong>in</strong>able</strong> U.S. <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
<strong>Expansion</strong>, a Necessity<br />
AUTHOR<br />
John S. Corb<strong>in</strong><br />
<strong>Aquaculture</strong> Plann<strong>in</strong>g &<br />
Advocacy LLC<br />
Introduction<br />
I<br />
n recent years, <strong>the</strong> scientificliterature<br />
has conta<strong>in</strong>ed numerous dire and<br />
controversial descriptions of <strong>the</strong> <strong>in</strong>creas<strong>in</strong>g<br />
decl<strong>in</strong>e of <strong>the</strong> oceans’ welldocumented,<br />
f<strong>in</strong>ite yield of seafood<br />
and its essential contribution to human<br />
nutritional well-be<strong>in</strong>g. Important mar<strong>in</strong>e<br />
ecosystems and fish populations<br />
may <strong>in</strong> fact be exhaustible, or at <strong>the</strong><br />
least damaged beyond recovery by<br />
human activity (Myers and Worm,<br />
2003; Pauly and Palomares, 2005;<br />
Pauly, 2009). Evidence <strong>in</strong>dicates that<br />
many of <strong>the</strong> world’s majorfisheries are<br />
be<strong>in</strong>g pushed beyond susta<strong>in</strong>able yields<br />
by excessive fish<strong>in</strong>g pressure and overstressed<br />
by loss of critical habitat through<br />
pollution, natural and man-made disasters,<br />
and <strong>the</strong> emerg<strong>in</strong>g specter of <strong>the</strong> impacts<br />
of global climate change (Mora<br />
et al., 2009; Food and Agriculture Organization<br />
[FAO], 2009a; FAO, 2009b).<br />
<strong>Expansion</strong> of capture fishery supplies<br />
for a fish-hungry world is deemed unlikely<br />
by most scientists, and aquaculture 1<br />
1 Def<strong>in</strong>itions (Source: NOAA, 2008)<br />
<strong>Aquaculture</strong> is <strong>the</strong> propagation and rear<strong>in</strong>g of aquatic<br />
plants and animals <strong>in</strong> controlled or selected aquatic<br />
environments for any commercial, recreational, or<br />
public purpose.<br />
<strong>Mar<strong>in</strong>e</strong> aquaculture is <strong>the</strong> cultivation of aquatic plants<br />
and animals <strong>in</strong> brackish or full strength sea water.<br />
Open ocean aquaculture is <strong>the</strong> rear<strong>in</strong>g of mar<strong>in</strong>e<br />
plants and animals under controlled conditions <strong>in</strong><br />
exposed, high-energy ocean environments beyond<br />
coastal <strong>in</strong>fluence.<br />
ABSTRACT<br />
Expanded development of mar<strong>in</strong>e aquaculture and aquaculture-enhanced fisheries<br />
for U.S. coastal and Exclusive Economic Zone (EEZ) waters has been a hot<br />
topic <strong>in</strong> recent years. Driv<strong>in</strong>g <strong>the</strong>se discussions have been <strong>the</strong> converg<strong>in</strong>g issues<br />
of America’s grow<strong>in</strong>g demand for quality seafood for a healthy diet, <strong>in</strong>creas<strong>in</strong>g reliance<br />
on imports to meet demand, <strong>in</strong> large part from <strong>the</strong> develop<strong>in</strong>g countries, and<br />
recurr<strong>in</strong>g concerns over <strong>the</strong> long-term stability of <strong>the</strong>se outside sources <strong>in</strong> a highly<br />
volatile seafood marketplace and <strong>in</strong>terconnected world economy. The United States<br />
has <strong>the</strong> largest and most diverse EEZ <strong>in</strong> <strong>the</strong> world. This resource is essential to domestic<br />
fisheries land<strong>in</strong>gs and could be <strong>the</strong> location for commercial open ocean<br />
aquaculture of a variety of economically important species. Recent efforts by <strong>the</strong><br />
Obama Adm<strong>in</strong>istration and Congress have focused on comprehensive ocean use<br />
plann<strong>in</strong>g and management as well as promulgat<strong>in</strong>g a permitt<strong>in</strong>g and leas<strong>in</strong>g regime<br />
for commercial aquaculture <strong>in</strong> federal waters. It is suggested that sufficient scientific<br />
understand<strong>in</strong>g exists for establish<strong>in</strong>g an <strong>in</strong>terim permitt<strong>in</strong>g and leas<strong>in</strong>g process<br />
for EEZ aquaculture while <strong>the</strong> regional multiuse ocean plann<strong>in</strong>g is carried out. The<br />
issues mentioned above are discussed <strong>in</strong> this article to support <strong>the</strong> contention that<br />
expanded domestic mar<strong>in</strong>e aquaculture development and aquaculture-enhanced<br />
fisheries are a necessity. Positive action to develop a strong, proactive federal policy<br />
framework for mar<strong>in</strong>e aquaculture expansion and to <strong>in</strong>crease <strong>in</strong>vestment <strong>in</strong> research,<br />
development, and demonstration of susta<strong>in</strong>able technologies should<br />
occur now.<br />
is widely viewed as one solution (albeit<br />
a partial solution) to <strong>in</strong>crease global<br />
seafood availability to meet <strong>the</strong> <strong>in</strong>evitable<br />
growth <strong>in</strong> demand from an expand<strong>in</strong>g<br />
population (FAO, 2009b).<br />
Despite <strong>the</strong>se awaken<strong>in</strong>g realizations<br />
and <strong>the</strong> potentially highly disruptive<br />
impacts on <strong>the</strong> American seafood<br />
<strong>in</strong>dustry, U.S. domestic aquaculture<br />
development <strong>in</strong> recent years has slowed<br />
and currently contributes very little to<br />
American seafood consumption. U.S.<br />
scientists, government policy makers,<br />
and a diverse array of stakeholders<br />
(proponents and opponents) cont<strong>in</strong>ue<br />
to debate <strong>the</strong> desirability of <strong>in</strong>vest<strong>in</strong>g<br />
<strong>in</strong> expand<strong>in</strong>g domestic sources of seafood<br />
through mar<strong>in</strong>e aquaculture and<br />
aquaculture-enhanced fisheries <strong>in</strong> <strong>the</strong><br />
face of <strong>the</strong> complex economic and social<br />
challenges fac<strong>in</strong>g America today<br />
(U.S. Department of Commerce<br />
[USDOC], 2007).<br />
In this unsettl<strong>in</strong>g climate, it is timely<br />
to consider <strong>the</strong> recent history and current<br />
status of American seafood consumption<br />
and supply and review<br />
projected product needs and <strong>the</strong> issues<br />
<strong>in</strong> meet<strong>in</strong>g those needs <strong>in</strong> <strong>the</strong> next 10<br />
to 20 years. The grow<strong>in</strong>g importance<br />
of <strong>the</strong> culture of macroalgae (seaweed)<br />
and microalgae to future world seafood<br />
May/June 2010 Volume 44 Number 3 7
and energy supplies must be noted;<br />
however, <strong>the</strong>se sources are not primary<br />
topics <strong>in</strong> this discussion (Forster,<br />
2008; Roesijadi et al., 2008). Fortunately,<br />
<strong>the</strong> United States has a diverse<br />
and experienced domestic fish<strong>in</strong>g<br />
<strong>in</strong>dustry and a fledgl<strong>in</strong>g mar<strong>in</strong>e aquaculture<br />
sector on which to craft solutions.<br />
Ongo<strong>in</strong>g discussions by <strong>the</strong><br />
federal government and Congress are<br />
also reviewed <strong>in</strong> <strong>the</strong> context of America’s<br />
expansive ocean resources <strong>in</strong> its<br />
enormous Exclusive Economic Zone<br />
(EEZ). The major issues constra<strong>in</strong><strong>in</strong>g<br />
<strong>the</strong> greater ocean use for expanded<br />
and susta<strong>in</strong>able 2 domestic seafood<br />
production are discussed, and recommendations<br />
for immediate action are<br />
considered.<br />
Why U.S. <strong>Mar<strong>in</strong>e</strong><br />
<strong>Aquaculture</strong> Development<br />
Is Important<br />
Seafood Consumption <strong>in</strong><br />
America Today<br />
Americans have a grow<strong>in</strong>g preference<br />
for <strong>in</strong>clud<strong>in</strong>g seafood of all types<br />
<strong>in</strong> <strong>the</strong>ir diets (Johnson, 2009). The<br />
U.S. population <strong>in</strong>creased from<br />
225 million <strong>in</strong> 1980 to 302 million<br />
<strong>in</strong> 2008. Dur<strong>in</strong>g that time period,<br />
per capita seafood consumption 3 <strong>in</strong>creased<br />
28% overall and 49% for <strong>the</strong><br />
fresh and frozen product forms<br />
(Table 1) (National <strong>Mar<strong>in</strong>e</strong> Fisheries<br />
2 For purposes of this article, susta<strong>in</strong>able mar<strong>in</strong>e aquaculture<br />
means projects that conserve natural resources<br />
and biodiversity, achieve <strong>the</strong> least degradation of <strong>the</strong><br />
environment, use techniques and technologies appropriate<br />
to a situation and site, generate profit or economic<br />
benefits <strong>in</strong> excess of costs, foster m<strong>in</strong>imal social<br />
disruptions and conflicts, and provide for community<br />
needs (Corb<strong>in</strong> and Young, 1997).<br />
3 Per capita consumption values, fish portion, are<br />
based on edible weight (edible meat), after conversion<br />
from round weight and weight of univalve and<br />
bivalve meats without <strong>the</strong> shell (source: NMFS,<br />
2009a).<br />
8 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
TABLE 1<br />
Increase <strong>in</strong> per capita consumption of seafood <strong>in</strong> <strong>the</strong> United States from 1980 to 2008 (source:<br />
NMFS, 2009a). a<br />
U.S. Population<br />
Per Capita Consumption (kg)<br />
Year<br />
(millions)<br />
Fresh/Frozen Form Total<br />
1980 225 3.6 5.7<br />
1990 247 4.3 6.8<br />
2000 280 4.6 6.9<br />
2008 302 5.3 7.2<br />
a<br />
Calculation of per capita consumption is based on round weight supply (whole fish) converted to edible<br />
weight and bivalve and univalve meats without shell.<br />
Service [NMFS], 2009a). A recent seafood<br />
survey showed that 65% of U.S.<br />
households purchased seafood for athome<br />
consumption at least once <strong>in</strong><br />
<strong>the</strong> previous year, whereas 83% of<br />
households purchased seafood <strong>in</strong> a restaurant<br />
(NMFS, 2009b).<br />
Fully 60% of all seafood products<br />
sold were <strong>in</strong> <strong>the</strong> fresh and frozen<br />
forms (National Fisheries Institute,<br />
2009). Studies show that Americans<br />
are seek<strong>in</strong>g <strong>the</strong> fresh product form,<br />
with 43% of households purchas<strong>in</strong>g<br />
fresh seafood products each year<br />
(Frey, 2008). The top 10 freshwater<br />
and mar<strong>in</strong>e species eaten <strong>in</strong> 2008 on<br />
a per capita basis were shrimp, canned<br />
tuna, salmon, pollack, tilapia, catfish,<br />
crab, cod, flatfish, and clams (National<br />
Fisheries Institute, 2009). Notably,<br />
three of <strong>the</strong>se species have substantial<br />
global mar<strong>in</strong>e aquaculture production<br />
bases, that is, shrimp, salmon, and<br />
clams (NMFS, 2009a). Moreover,<br />
growth <strong>in</strong> per capita consumption <strong>in</strong><br />
recent years occurred almost exclusively<br />
among <strong>the</strong> aquacultured species<br />
(Anderson and Shamshak, 2008).<br />
A significant number of consumers<br />
eat seafood at <strong>the</strong> high-end, white table<br />
cloth restaurant segment of <strong>the</strong> food<br />
service <strong>in</strong>dustry. Although not all<br />
serve seafood, <strong>the</strong> National Restaurant<br />
Association (2009) numbers commer-<br />
cial establishments at 945,000 nationwide,<br />
with 2009 sales at $566 billion.<br />
U.S. consumers spent an estimated<br />
$46.8 billion <strong>in</strong> 2008 for fishery products<br />
<strong>in</strong> food service establishments<br />
(restaurants, carryouts, caterers, etc.).<br />
A substantial number of consumers<br />
also purchase products from traditional<br />
supermarket seafood counters, with<br />
<strong>the</strong> 2008 figure be<strong>in</strong>g $22.7 billion<br />
(NMFS, 2009a). In addition, data <strong>in</strong>dicate<br />
that approximately 88% of all<br />
fresh seafood sales occur <strong>in</strong> traditional<br />
supermarkets. Fresh seafood consists<br />
of shellfish (59% of dollar value) and<br />
f<strong>in</strong>fish (41% of dollar value). Both categories<br />
grew <strong>in</strong> 2007 sales, 4.6% and<br />
3.7%, respectively, over 2006 values.<br />
More demonstrative, basel<strong>in</strong>e sales<br />
for seafood suppliers grew 8% <strong>in</strong> <strong>the</strong><br />
same period and represented 90% of<br />
seafood department dollars, <strong>in</strong>dicat<strong>in</strong>g<br />
that consumers are buy<strong>in</strong>g seafood as<br />
an everyday purchase (Frey, 2008).<br />
Seafood consumers <strong>in</strong> general represent<br />
a cross section of <strong>the</strong> population.<br />
However, recent studies have<br />
shown that older adults, that is, <strong>the</strong><br />
70 million matur<strong>in</strong>g “baby boomers,”<br />
eat significantly more seafood than<br />
o<strong>the</strong>r age groups. Adults 50–64 years<br />
of age eat 35% more seafood than<br />
<strong>the</strong> national average, and adults over<br />
65 eat 53% more. Moreover, certa<strong>in</strong>
ethnic groups favor seafood; Hispanics<br />
consume 24% more than non-<br />
Hispanics and represent <strong>the</strong> largest<br />
ethnic group <strong>in</strong> <strong>the</strong> United States at<br />
38 million members ( Johnson, 2009),<br />
and Asian Americans, which represent<br />
5% of <strong>the</strong> population, have strong<br />
preferences for fresh seafood products<br />
(NMFS, 2009b).<br />
Farmed seafood provides <strong>the</strong> food<br />
service <strong>in</strong>dustry and consumers <strong>in</strong> general<br />
several much sought after characteristics,<br />
<strong>in</strong>clud<strong>in</strong>g predictable and<br />
consistent supply, greater portion control,<br />
and enhanced freshness, quality,<br />
and traceability. Among <strong>the</strong> major reasons<br />
Americans are seek<strong>in</strong>g out seafood<br />
today is <strong>the</strong> associated health benefits<br />
of consum<strong>in</strong>g <strong>the</strong> high-quality aquatic<br />
prote<strong>in</strong>s and long cha<strong>in</strong> omega-3 fatty<br />
acids (eicosapentaenoic acid [EPA]<br />
and docosahexaenoic acid [DHA])<br />
present <strong>in</strong> <strong>the</strong> products. Studies <strong>in</strong>dicate<br />
that <strong>the</strong>se chemicals can improve<br />
cellular function, bra<strong>in</strong>, and nervous<br />
system function, and cardiovascular<br />
health (Nesheim and Yakt<strong>in</strong>e, 2007).<br />
O<strong>the</strong>r reasons for <strong>the</strong> <strong>in</strong>creas<strong>in</strong>g popularity<br />
of seafood relate to <strong>the</strong> food service<br />
<strong>in</strong>dustry’s development of a wide<br />
variety of value-added, easy-to-prepare<br />
seafood products and <strong>the</strong> recent supermarket<br />
trend toward self-service seafood<br />
departments supplied with<br />
prepackaged, case-ready products<br />
(Johnson, 2009).<br />
The October 2009 survey of chefs<br />
by <strong>the</strong> American Cul<strong>in</strong>ary Federation<br />
fur<strong>the</strong>r supports <strong>the</strong> trend for greater<br />
seafood consumption. The feedback<br />
on <strong>the</strong> “hottest menu trends <strong>in</strong><br />
2010” <strong>in</strong>dicated that <strong>the</strong> top restaurant<br />
<strong>the</strong>me was purchase of locally sourced<br />
produce, meat, and seafood. Next was<br />
susta<strong>in</strong>ability of production techniques<br />
to address <strong>the</strong> “green<strong>in</strong>g” of <strong>the</strong><br />
American consciousness. Also mentioned<br />
as highly popular were <strong>the</strong><br />
seafood-related <strong>the</strong>mes of us<strong>in</strong>g organically<br />
grown products and nontraditional<br />
fish (National Restaurant<br />
Association, 2009).<br />
These strong <strong>in</strong>dicators among<br />
food and food service providers and<br />
<strong>the</strong>ir customers underscore <strong>the</strong> U.S.<br />
consumer’s grow<strong>in</strong>g desire for susta<strong>in</strong>ably<br />
and locally produced seafood.<br />
Additional evidence of seafood’s importance<br />
is <strong>the</strong> <strong>in</strong>creas<strong>in</strong>g use of ecolabel<strong>in</strong>g<br />
by environmental and <strong>in</strong>dustry<br />
groups (e.g., World Wildlife Fund, <strong>the</strong><br />
Global <strong>Aquaculture</strong> Alliance, <strong>the</strong> <strong>Mar<strong>in</strong>e</strong><br />
Stewardship Council) to <strong>in</strong>fluence<br />
consumer behavior and to promote<br />
selection of susta<strong>in</strong>ably produced<br />
seafood products (World Wildlife<br />
Fund, 2009; Global <strong>Aquaculture</strong> Alliance,<br />
2009; <strong>Mar<strong>in</strong>e</strong> Stewardship Council,<br />
2009; Anderson and Shamshak,<br />
2008; FAO, 2009b). Fur<strong>the</strong>r, <strong>the</strong>re<br />
is a grow<strong>in</strong>g number of “seafood<br />
choice” cards (e.g., <strong>the</strong> Monterey Bay<br />
Aquarium and <strong>the</strong> Georgia Aquarium)<br />
to help consumers identify best and<br />
worst seafood choices based on <strong>the</strong> susta<strong>in</strong>ability<br />
of <strong>the</strong> source (Monterey Bay<br />
Aquarium, 2009; Georgia Aquarium,<br />
2009).<br />
Seafood Supply<br />
<strong>in</strong> America Today<br />
Annual U.S. seafood consumption<br />
(capture and culture sources) of edible<br />
fishery products (domestic commercial<br />
land<strong>in</strong>gs + imports − exports = total<br />
consumption) has varied from 4.3 mmt<br />
(9,532 million pounds) to 5.7 mmt<br />
(12,492 million pounds) round weight 4<br />
between 1999 and 2008 (Table 2).<br />
The tendency was toward <strong>in</strong>creas<strong>in</strong>g<br />
4 Amounts for production values are presented as metric<br />
tons of round weight or weight of whole fish as it<br />
leaves <strong>the</strong> water and univalve and bivalve meats without<br />
<strong>the</strong> shell (source: NMFS, 2009a).<br />
values with 5.4 mmt (11,836 million<br />
pounds) consumed <strong>in</strong> 2008. For visual<br />
reference, a metric ton is approximately<br />
equivalent <strong>in</strong> size to a rectangle 4 feet<br />
(1.2 meters) wide, 4 feet (1.2 m) long,<br />
and 5 feet (1.5 m) high, and a million<br />
metric tons is estimated to be equivalent<br />
to 251 American football fields<br />
covered one layer deep with standard<br />
40 feet (12.2 m) shipp<strong>in</strong>g conta<strong>in</strong>ers<br />
filled to maximum load. 5<br />
Domestic commercial fishery land<strong>in</strong>gs<br />
also varied over <strong>the</strong> same time<br />
frame from a low of 3.0 mmt (6,633<br />
million pounds) <strong>in</strong> 2008 to a high of<br />
3.6 mmt (7,997 million pounds) <strong>in</strong><br />
2005. Notably, <strong>the</strong> United States exports<br />
significant amounts of edible seafood:<br />
values between 1999 and 2008<br />
varied between a low of 1.9 mmt<br />
(4,129 million pounds) <strong>in</strong> 1999 to<br />
2.9 mmt (6,462 million pounds) <strong>in</strong><br />
2004, with <strong>the</strong> major recipients be<strong>in</strong>g<br />
Ch<strong>in</strong>a, Japan, and Canada. Edible seafood<br />
imports, however, have <strong>in</strong>creased<br />
every year from a low of 3.5 mmt<br />
(7,630 million pounds) <strong>in</strong> 1999 to a<br />
high of 4.9 mmt (10,763 million<br />
pounds) <strong>in</strong> 2007, until a slight decl<strong>in</strong>e<br />
<strong>in</strong> 2008 when <strong>the</strong> value was 4.8 mmt<br />
(10,456 million pounds) (NMFS,<br />
2009a).<br />
5 For a visual perspective, <strong>the</strong> approximate size of a<br />
metric ton and a million metric tons of fish and shellfish<br />
were calculated.<br />
Metric ton<br />
One 40 foot (ft) shipp<strong>in</strong>g conta<strong>in</strong>er = 302 square (sq)<br />
ft = 26.7 metric tons (mt) maximum load.<br />
1 mt = 11.3 sq ft x 7.5 ft = 84.75 cubic (cu) ft<br />
1 mt = 84.75 cu ft = a rectangle approximately 4 ft<br />
wide, 4 ft long and 5 ft high.<br />
One million metric tons<br />
One American football field=100yards(yd)by<br />
50 yd = 45,000 sq ft<br />
One 40 ft shipp<strong>in</strong>g conta<strong>in</strong>er = 302 sq ft = 26.7 mt<br />
maximum load.<br />
One American football field is covered by 149 conta<strong>in</strong>ers<br />
or 3,978.3 mt.<br />
1 million mt = 251 American football fields covered<br />
one (1) deep with standard 40 ft shipp<strong>in</strong>g conta<strong>in</strong>ers<br />
May/June 2010 Volume 44 Number 3 9
TABLE 2<br />
United States supply of edible fishery products, 1999 to 2008 (millions of metric tons)<br />
(source: NMFS, 2009a). a,b<br />
Year Domestic Land<strong>in</strong>gs Imports Exports Total Supply<br />
1999 3.09 3.45 1.87 4.68<br />
2000 3.13 3.54 2.08 4.59<br />
2001 3.31 3.62 2.61 4.31<br />
2002 3.26 3.98 2.53 4.77<br />
2003 3.40 4.37 2.44 5.34<br />
2004 3.53 4.46 2.92 5.06<br />
2005 3.62 4.60 2.89 5.33<br />
2006 3.55 4.87 2.83 5.59<br />
2007 3.39 4.87 2.61 5.65<br />
2008 3.00 4.73 2.38 5.36<br />
a Domestic land<strong>in</strong>gs + imports − exports = total edible supply.<br />
b Values <strong>in</strong> round weight or weight of fish as it comes out of <strong>the</strong> water and bivalve and univalve meats<br />
without shell.<br />
Recent reports <strong>in</strong>dicate that 84% of<br />
U.S. seafood consumption is imported<br />
(NMFS, 2009b). In 2008, imports of<br />
edible fishery products were valued at a<br />
record $14.2 billion. This <strong>in</strong>cluded<br />
4.4 billion pounds <strong>in</strong> <strong>the</strong> fresh and frozen<br />
product forms, valued at $12.1 billion.<br />
These imports <strong>in</strong>cluded shrimp<br />
products valued at $4.1 billion, salmon<br />
valued at $1.6 billion, and tuna valued<br />
at $601 million. Nonedible fishery<br />
products imported by <strong>the</strong> <strong>in</strong>dustry<br />
for fish meal, oils, etc., <strong>in</strong> <strong>the</strong> same<br />
year were valued at an additional<br />
$14.3 billion. Thus, <strong>the</strong> contribution<br />
of imports to U.S. fisheries product<br />
needs <strong>in</strong> 2008 was $28.5 billion<br />
(NMFS, 2009a).<br />
In 2007, <strong>the</strong> United States replaced<br />
Japan, <strong>the</strong> long-time leader, as <strong>the</strong><br />
world’s lead<strong>in</strong>gimporteroffishery<br />
products. Notably, Japan has <strong>the</strong> highest<br />
per capita seafood consumption<br />
of any developed country at 59.3 kg<br />
(131 lb) per person or eight times<br />
that of <strong>the</strong> United States (NMFS,<br />
2009a). Moreover, <strong>the</strong> seafood balance<br />
10 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
of trade deficit was over $10 billion <strong>in</strong><br />
2007, an <strong>in</strong>crease of almost 60% from<br />
$6.8 billion <strong>in</strong> 1998 (ERS, 2009).<br />
Major 2008 source countries for seafood<br />
imports by volume <strong>in</strong>cluded Ch<strong>in</strong>a<br />
22%, Thailand 15%, Canada 13%, Indonesia<br />
6%, Chile 5%, Viet Nam 5%,<br />
and Ecuador 4% (NMFS, 2009a).<br />
Domestic aquaculture’s total<br />
(freshwater and mar<strong>in</strong>e) contribution<br />
to U.S. seafood supplies has risen,<br />
more or less steadily, <strong>in</strong> production<br />
volume from 135,747 mt (300 million<br />
pounds) <strong>in</strong> 1983 to 417,647 mt<br />
(923 million pounds), valued at<br />
$1.2 billion <strong>in</strong> 2003 (NMFS,2009a).<br />
In recent years (2004 to 2007), growth<br />
has been erratic due <strong>in</strong> large part to ris<strong>in</strong>g<br />
competition with lower priced foreign<br />
imports (Forster and Nash, 2008). Values<br />
ranged between a low of 362 mmt<br />
(800 million pounds) <strong>in</strong> 2006 and a<br />
high of 408 mmt (906 million pounds)<br />
<strong>in</strong> 2004, although product value has<br />
tended to <strong>in</strong>crease (Table 3).<br />
By contrast, global aquaculture<br />
production between 2004 and 2007<br />
TABLE 3<br />
Volume and value of recent United States<br />
aquaculture production from 2004 to 2007<br />
(source: NMFS, 2009a). a<br />
Volume Value<br />
Year (1000s mt) (millions $)<br />
2004 468 1,068<br />
2005 376 1,118<br />
2006 362 1,234<br />
2007 373 1,204<br />
a Values <strong>in</strong> round weight or weight of fish as it<br />
comes out of <strong>the</strong> water and univalve and bivalve<br />
meats without <strong>the</strong> shell.<br />
<strong>in</strong>creased 20%, from 41.9 mmt<br />
(92.6 billion pounds) to 50.3 mmt<br />
(111 billion pounds), valued at<br />
$70 billion (NMFS, 2009a). Global<br />
aquaculture now provides 50% of edible<br />
seafood for <strong>the</strong> world population<br />
(FAO, 2009b) on <strong>the</strong> basis of <strong>the</strong> culture<br />
of more than 300 aquatic species<br />
(Leung et al., 2007). Comparatively,<br />
Americawas<strong>the</strong>thirdlargestconsumer<br />
of seafood <strong>in</strong> <strong>the</strong> world by volume,<br />
beh<strong>in</strong>d Ch<strong>in</strong>a and Japan, but has<br />
steadily dropped to 13th <strong>in</strong> volume<br />
production from aquaculture, as<br />
countries such as Ch<strong>in</strong>a, India, Thailand,<br />
Viet Nam, and Indonesia <strong>in</strong>vest<br />
<strong>in</strong> expansion of <strong>the</strong>ir <strong>in</strong>dustries<br />
(FAO, 2009c). U.S. aquatic farm<strong>in</strong>g<br />
provided just 7.2% of domestic demand<br />
<strong>in</strong> 2007, mostly freshwater<br />
catfish and trout (National Oceanic<br />
and Atmospheric Adm<strong>in</strong>istration<br />
[NOAA], 2008).<br />
Focus<strong>in</strong>g on <strong>the</strong> mar<strong>in</strong>e aquaculture<br />
component of U.S. production—<br />
mostly made up of salmon, oysters,<br />
clams, mussels, and shrimp—<strong>the</strong><br />
annual wholesale value is around<br />
$200 million or less than 20% of <strong>the</strong><br />
total <strong>in</strong>dustry value. <strong>Mar<strong>in</strong>e</strong> aquaculture<br />
today provides only 1.5% of<br />
U.S. seafood supply (NOAA, 2008).<br />
Seafood imports clearly dom<strong>in</strong>ate
U.S. supplies, and estimates <strong>in</strong>dicate<br />
that 50% of imports are farmed, mostly<br />
<strong>in</strong> develop<strong>in</strong>g countries, for example,<br />
Ch<strong>in</strong>a, Thailand, and Indonesia<br />
(NOAA, 2008; NMFS, 2009a).<br />
Overall, this discussion <strong>in</strong>dicates<br />
that <strong>the</strong> U.S. seafood economy (capture<br />
and culture products and raw materials)<br />
<strong>in</strong> total makes a significant<br />
direct economic impact on American<br />
commerce each year, even without tak<strong>in</strong>g<br />
<strong>in</strong>to account <strong>the</strong> economic impacts<br />
of secondary <strong>in</strong>dustries (e.g., seafood<br />
wholesalers and retailers, transportation<br />
and storage providers, harbor support<br />
facilities providers, etc.). The total<br />
value of exported (edible and nonedible)<br />
fishery products plus <strong>the</strong> total<br />
value of imported products was<br />
$51.9 billion <strong>in</strong> 2008. From ano<strong>the</strong>r<br />
perspective, domestic fishery land<strong>in</strong>gs<br />
and aquaculture production (freshwater<br />
and mar<strong>in</strong>e sources) had an estimated<br />
value of $5.4 billion <strong>in</strong> 2008<br />
(NMFS, 2009a).<br />
The contribution of mar<strong>in</strong>e recreational<br />
fish<strong>in</strong>g to provid<strong>in</strong>g fish for <strong>the</strong><br />
American diet should not be overlooked<br />
<strong>in</strong> a discussion of seafood supply.<br />
In 2008, almost 12 million anglers<br />
spent $30 billion on nearly 85 million<br />
mar<strong>in</strong>e recreational fish<strong>in</strong>g trips on <strong>the</strong><br />
Atlantic, Gulf, and Pacific Coasts. The<br />
total mar<strong>in</strong>e catch was conservatively<br />
estimated at nearly 464 million fish,<br />
of which almost 58% were released.<br />
Total harvest weight was estimated at<br />
112,217 mt (248 million pounds),<br />
which would have had a disproportionately<br />
higher impact on <strong>the</strong> diets<br />
of residents of coastal states where <strong>the</strong><br />
fish<strong>in</strong>g activity occurred (NMFS,<br />
2009a) and where 50% of <strong>the</strong> U.S. population<br />
lives with<strong>in</strong> 80 km (50 miles)<br />
of <strong>the</strong> coast (U.S. Commission on<br />
Ocean Policy [USCOP], 2004).<br />
It is relevant to note that of <strong>the</strong> top<br />
10 recreational species <strong>in</strong> 2008, seven<br />
(striped bass, spotted sea trout, yellow<br />
f<strong>in</strong> tuna, red drum, dolph<strong>in</strong> fish, summer<br />
flounder, and black drum) are<br />
among <strong>the</strong> targets of public sector, private<br />
sector, and university aquaculture<br />
research or fledgl<strong>in</strong>g mar<strong>in</strong>e stock enhancement<br />
efforts (NMFS, 2009a;<br />
NOAA, 2009a). <strong>Mar<strong>in</strong>e</strong> stock enhancement<br />
of recreational and commercial<br />
fisheriesis<strong>in</strong><strong>the</strong>processof<br />
be<strong>in</strong>g recognized as a valuable tool<br />
for fisheries managers. More robust<br />
domestic coastal and ocean fisheries<br />
could add significantly to seafood<br />
supplies and expand <strong>the</strong> economy<br />
while help<strong>in</strong>g preserve America’s long<br />
and cherished cultural heritage <strong>in</strong> fish<strong>in</strong>g<br />
(USCOP, 2004).<br />
Projected U.S. Seafood<br />
Demand<br />
Global Context<br />
Fill<strong>in</strong>g America’s future seafood requirements<br />
by a greater reliance on imports<br />
should be considered <strong>in</strong> <strong>the</strong><br />
context of global seafood supply and<br />
demand projections as well as potential<br />
market forces. <strong>Aquaculture</strong> has been<br />
<strong>the</strong> fastest grow<strong>in</strong>g segment of world<br />
food production, expand<strong>in</strong>g an average<br />
of 9% per year s<strong>in</strong>ce 1950, although <strong>the</strong><br />
rate has been slow<strong>in</strong>g <strong>in</strong> recent years.<br />
<strong>Mar<strong>in</strong>e</strong> capture fisheries supplies—<br />
roughly 90% of <strong>the</strong> total supplies from<br />
fisheries, with <strong>the</strong> balance from <strong>in</strong>land<br />
fisheries—began to level off <strong>in</strong> <strong>the</strong> late<br />
1980s at around 90 mmt (198 billion<br />
pounds) per year. S<strong>in</strong>ce <strong>the</strong>n, virtually<br />
all <strong>in</strong>creases <strong>in</strong> seafood supplies have<br />
been through expansion of freshwater<br />
and mar<strong>in</strong>e aquaculture, with mar<strong>in</strong>e<br />
farm<strong>in</strong>g contribut<strong>in</strong>g roughly 38% or<br />
19 mmt (41 billion pounds) <strong>in</strong> 2006<br />
(FAO, 2009b).<br />
As <strong>the</strong> global human population<br />
grows, demand for aquatic prote<strong>in</strong><br />
will most certa<strong>in</strong>ly <strong>in</strong>crease because of<br />
<strong>the</strong> critical contribution of seafood to<br />
<strong>the</strong> diets of <strong>the</strong> developed and develop<strong>in</strong>g<br />
countries around <strong>the</strong> world (FAO,<br />
2009b). Demand projections vary<br />
with time frame and amounts, but all<br />
conclude that much more supply will<br />
be needed and future <strong>in</strong>creases must<br />
come from aquaculture <strong>in</strong> all its<br />
forms. One study <strong>in</strong>dicates that just<br />
to ma<strong>in</strong>ta<strong>in</strong> current levels of worldwide<br />
per capita consumption, aquaculture<br />
will need to reach 80 mmt<br />
(176.8 billion pounds) by 2050 or<br />
60% more than its present amount<br />
(FAO, 2003). O<strong>the</strong>r estimates forecast<br />
a potential <strong>in</strong>crease <strong>in</strong> world per capita<br />
consumption from 16 kg (35.4 lb) to<br />
21 kg (46.4 lb) and 2.3 billion additional<br />
people, requir<strong>in</strong>g an additional<br />
40 mmt (88.4 billion pounds) to<br />
60 mmt (132.6 billion pounds)<br />
from aquaculture production by<br />
2030 (Silva, 2001). A more urgent<br />
world seafood demand projection is<br />
provided by Delgado et al. (2003),<br />
who forecast <strong>the</strong> need for between<br />
68.6 mmt (151 billion pounds) and<br />
83.6 mmt (184 billion pounds) from<br />
aquaculture production by 2020,<br />
which translates to between 18.3 mmt<br />
(40 billion pounds) and 33 mmt (72.8<br />
billion pounds) more than 2007<br />
supplies <strong>in</strong> just 13 years (NMFS,<br />
2009a).<br />
Importantly, <strong>the</strong>se authors also<br />
question if meet<strong>in</strong>g <strong>in</strong>creases <strong>in</strong> supplies<br />
through greater aquaculture production<br />
is possible, with <strong>the</strong> exist<strong>in</strong>g<br />
trends <strong>in</strong> development, resource use,<br />
and technology <strong>in</strong>tensification<strong>in</strong><strong>the</strong><br />
global <strong>in</strong>dustry (Delgado et al., 2003;<br />
FAO, 2009b). Their skepticism seems<br />
warranted upon fur<strong>the</strong>r consideration;<br />
for example, an aquaculture production<br />
<strong>in</strong>crease between 18.3 and 33 mmt <strong>in</strong><br />
13 years would mean an expansion of<br />
almost 1 to 1.5 times <strong>the</strong> size of <strong>the</strong><br />
salmon <strong>in</strong>dustry <strong>in</strong> 2006 (volume at<br />
May/June 2010 Volume 44 Number 3 11
1.65 mmt or 3.64 million pounds) <strong>in</strong><br />
each of <strong>the</strong> next 13 years. A daunt<strong>in</strong>g<br />
task at best! Notably, <strong>the</strong> global<br />
salmon aquaculture <strong>in</strong>dustry took<br />
over 20 years to grow from 80 thousand<br />
metric tons (tmt) (17.6 million<br />
pounds) to 1.65 mmt <strong>in</strong> 2006 (Asche<br />
and Tveteras, 2009).<br />
U.S. Projections<br />
Future U.S. seafood demand has<br />
several important drivers go<strong>in</strong>g forward,<br />
namely, projected population<br />
growth and <strong>the</strong> cont<strong>in</strong>ued and grow<strong>in</strong>g<br />
popularity of seafood as a prote<strong>in</strong><br />
choice by consumers, due <strong>in</strong> large<br />
part to trends <strong>in</strong> buy<strong>in</strong>g locally, seek<strong>in</strong>g<br />
variety, and eat<strong>in</strong>g for better<br />
health.<br />
The U.S. population is expected to<br />
grow from 302 million people <strong>in</strong> 2008<br />
to 341 million people <strong>in</strong> 2020 and<br />
374 million <strong>in</strong> 2030 (U.S. Census Bureau,<br />
2009). Us<strong>in</strong>g <strong>the</strong> 2008 consumption<br />
value of 7.2 kg (16 lb) per<br />
person and a current national consumption<br />
figure of approximately<br />
2.17 mmt (4,896 million pounds of<br />
edible weight 2 ) per year as a benchmark,<br />
<strong>the</strong> necessary seafood supply<br />
just to ma<strong>in</strong>ta<strong>in</strong> <strong>the</strong> 2008 per capita<br />
value would be 2.46 mmt (5,437 million<br />
pounds) <strong>in</strong> 2020 and 2.69 mmt<br />
(5,945 million pounds) <strong>in</strong> 2030.<br />
Tak<strong>in</strong>g <strong>in</strong>to account <strong>the</strong> <strong>in</strong>creas<strong>in</strong>g<br />
popularity of seafood, particularly<br />
among certa<strong>in</strong> demographics, projected<br />
demand could be even higher.<br />
For example, <strong>the</strong> American Heart Association<br />
has advocated that Americans<br />
should eat seafood twice a week<br />
ra<strong>the</strong>r than <strong>the</strong> current average of<br />
once a week, and this would <strong>in</strong>crease<br />
current demand by 0.68 mmt (1.5 billion<br />
pounds) (USCOP, 2004). Recent<br />
estimates <strong>in</strong>dicate that by 2020, per<br />
capita consumption values could <strong>in</strong>crease<br />
from 7.2 kg (16 lb) to 8.6 kg<br />
12 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
(19 lb) (Anderson and Shamshak,<br />
2008). The <strong>in</strong>creases <strong>in</strong> population<br />
and per capita consumption could<br />
push <strong>the</strong> amount of seafood needed<br />
to 2.93 mmt (6,475 million pounds)<br />
<strong>in</strong> 2020 and 3.33 mmt (7,359 million<br />
pounds) <strong>in</strong> 2030 or 1 mmt more than<br />
today.<br />
The American seafood production,<br />
process<strong>in</strong>g, and distribution <strong>in</strong>dustry<br />
and its political supporters and retail<br />
customers are fac<strong>in</strong>g a critical choice<br />
to meet projected demand. Ei<strong>the</strong>r expand<br />
susta<strong>in</strong>able domestic sources of<br />
seafood through greater aquaculture<br />
production and greater fisheries<br />
management, restoration, and enhancement<br />
activities or rely fur<strong>the</strong>r<br />
on imports, largely from develop<strong>in</strong>g<br />
countries.<br />
Uncerta<strong>in</strong>ties <strong>in</strong><br />
Meet<strong>in</strong>g Future U.S.<br />
Seafood Demand<br />
It is important to exam<strong>in</strong>e some<br />
critical issues, o<strong>the</strong>r than basic global<br />
seafood supply, that are related to <strong>the</strong><br />
potential long-term susta<strong>in</strong>ability and<br />
stability of <strong>the</strong> U.S. option of import<strong>in</strong>g<br />
substantial amounts of seafood<br />
over <strong>the</strong> next two decades. Anderson<br />
and Shamshak (2008) provide valuable<br />
<strong>in</strong>sight <strong>in</strong>to <strong>the</strong> complexity, <strong>in</strong>stability,<br />
and far-reach<strong>in</strong>g impacts of <strong>the</strong><br />
global seafood <strong>in</strong>dustry. They characterize<br />
<strong>the</strong> <strong>in</strong>dustry as follows:<br />
■ The global seafood <strong>in</strong>dustry is <strong>the</strong><br />
most complex and diverse animal<br />
prote<strong>in</strong> sector, with over 800 species<br />
traded, rang<strong>in</strong>g from urch<strong>in</strong>s<br />
to oysters to swordfish. The <strong>in</strong>dustry<br />
uses harvest<strong>in</strong>g technologies<br />
that date back thousands of years<br />
as well as capture and culture technologies<br />
that are among <strong>the</strong> most<br />
advanced <strong>in</strong> <strong>the</strong> world.<br />
■ International trade <strong>in</strong> seafood is valued<br />
at more than twice <strong>the</strong> trade <strong>in</strong><br />
all o<strong>the</strong>r meats and poultry comb<strong>in</strong>ed.<br />
■ The <strong>in</strong>dustry is fragmented with<br />
tens of thousands of companies<br />
spread around <strong>the</strong> world.<br />
■ The <strong>in</strong>dustry faces <strong>the</strong> most bureaucratic<br />
and <strong>in</strong>efficient regulatory<br />
environment, relative to any o<strong>the</strong>r<br />
food sector.<br />
■ Capture fisheries are known to<br />
waste significant resources through<br />
by-catch and <strong>in</strong>efficient process<strong>in</strong>g.<br />
Moreover, <strong>the</strong> <strong>in</strong>dustry throughout<br />
its history has often been plagued<br />
with excess capacity, overcapitalization,<br />
and/or regulated <strong>in</strong>efficiency.<br />
■ Seafood is traded <strong>in</strong> a global marketplace<br />
that lacks transparency.<br />
Accurate and timely <strong>in</strong>formation<br />
about prices and market conditions<br />
is difficult to obta<strong>in</strong> or nonexistent.<br />
The authors conclude that, “All<br />
<strong>the</strong>se factors result <strong>in</strong> a seafood sector<br />
which is highly volatile compared<br />
with o<strong>the</strong>r animal prote<strong>in</strong> sectors.<br />
The factors above underm<strong>in</strong>e efficiency,<br />
market plann<strong>in</strong>g, and market<br />
development.”<br />
In addition to <strong>the</strong> potentially disruptive<br />
factors mentioned above,<br />
which are likely to cont<strong>in</strong>ue for <strong>the</strong><br />
foreseeable future, <strong>the</strong>re are o<strong>the</strong>r important<br />
reasons why ma<strong>in</strong>ta<strong>in</strong><strong>in</strong>g U.S.<br />
accessibility to adequate seafood<br />
imports may be viewed as a “risky<br />
proposition” over <strong>the</strong> long term. Strategically,<br />
<strong>the</strong> important supply question<br />
is: Could <strong>the</strong> adequacy of seafood<br />
supplies from imports, <strong>in</strong> what already<br />
is a volatile global marketplace, be jeopardized<br />
by <strong>the</strong> anticipated <strong>in</strong>creases <strong>in</strong><br />
regional competition for product, <strong>the</strong><br />
growth of mega cities <strong>in</strong> seafood source<br />
regions, Ch<strong>in</strong>a’s dom<strong>in</strong>ance <strong>in</strong> <strong>the</strong> seafood<br />
trade, and <strong>the</strong> <strong>in</strong>creas<strong>in</strong>g likelihood<br />
of unforeseen geopolitical events<br />
and disputes?
Fishery products are essential commodities<br />
for both develop<strong>in</strong>g and<br />
developed countries, and regional<br />
competition for seafood sources can<br />
be expected to <strong>in</strong>crease <strong>in</strong> <strong>the</strong> decades<br />
to come. Per capita aquatic prote<strong>in</strong><br />
consumption globally has been ris<strong>in</strong>g<br />
<strong>the</strong> last few decades, with estimates<br />
for 2006 at 16.7 kg (35.9 lb). Importantly,<br />
fish today provide more than<br />
3 billion people with 15% or more of<br />
<strong>the</strong>ir annual animal prote<strong>in</strong> consumption<br />
(FAO, 2009b).<br />
Develop<strong>in</strong>g countries <strong>in</strong> <strong>the</strong> Asia-<br />
Pacific region accounted for approximately<br />
79% of global fishery<br />
production <strong>in</strong> 2006 (capture and culture<br />
sources), and this value is expected<br />
to <strong>in</strong>crease with time (FAO, 2009b).<br />
Japan, <strong>the</strong> United States, and <strong>the</strong> European<br />
Union are <strong>the</strong> major markets<br />
for <strong>the</strong>ir exports, with a significant<br />
total market share of 72% of <strong>the</strong> total<br />
2006 value. With respect to aquaculture<br />
production alone, <strong>the</strong> Asia-Pacific<br />
region today produces 90% of <strong>the</strong><br />
farmed food and 80% of <strong>the</strong> world<br />
value. The region’s dom<strong>in</strong>ance as a<br />
critical supplier of cultured products<br />
is expected to cont<strong>in</strong>ue well <strong>in</strong>to this<br />
century (FAO, 2009b).<br />
Several emerg<strong>in</strong>g trends <strong>in</strong> Asia<br />
could direct seafood supplies away<br />
from <strong>the</strong> export channels to <strong>the</strong> United<br />
States, that is, create a more competitive<br />
regional environment for products.<br />
The majority of <strong>the</strong> world’s population<br />
<strong>in</strong>crease <strong>in</strong> <strong>the</strong> next 20 years<br />
will occur <strong>in</strong> <strong>the</strong> Asia-Pacific region,<br />
and it is anticipated that <strong>the</strong> regional<br />
cultures at all levels of <strong>the</strong> economic<br />
spectrum will ma<strong>in</strong>ta<strong>in</strong> <strong>the</strong>ir preferences<br />
for seafood; for example, per<br />
capita consumption amounts <strong>in</strong> higher<br />
<strong>in</strong>come countries are expected to cont<strong>in</strong>ue<br />
to grow. Ris<strong>in</strong>g standards of<br />
liv<strong>in</strong>g, <strong>in</strong>creas<strong>in</strong>g <strong>in</strong>comes, and diversification<br />
of diets <strong>in</strong> selected parts of <strong>the</strong><br />
region are expected to ma<strong>in</strong>ta<strong>in</strong> and/or<br />
expand demand for seafood (FAO,<br />
2009b). To illustrate, Asian countries,<br />
o<strong>the</strong>r than Ch<strong>in</strong>a, experienced an <strong>in</strong>crease<br />
of 5.9 kg (13.0 lb) <strong>in</strong> per capita<br />
consumption between 2003 and 2007<br />
(Johnson, 2008).<br />
Ano<strong>the</strong>r notable trend that will<br />
modify dietary patterns and <strong>in</strong>fluence<br />
<strong>the</strong> global distribution of seafood is<br />
<strong>the</strong> urbanization of <strong>the</strong> world population,<br />
that is, <strong>the</strong> movement of people<br />
<strong>in</strong>to megacities located <strong>in</strong> Europe,<br />
Asia, Africa, and North and South<br />
America. In 2008, a milestone was<br />
reached when more of <strong>the</strong> world’s population<br />
lived <strong>in</strong> cities than <strong>in</strong> rural<br />
environments. By 2050, <strong>the</strong> urban<br />
population will double from 3.3 billion<br />
<strong>in</strong> 2007 to 6.4 billion or two<br />
thirds of <strong>the</strong> total projected world population<br />
of 9.2 billion. The majority of<br />
<strong>the</strong> growth will be absorbed by cities <strong>in</strong><br />
lesser develop<strong>in</strong>g countries (FAO,<br />
2009b).<br />
City dwellers are projected to have<br />
greater wealth, <strong>in</strong>creased dietary<br />
choices, and improved ability to pay<br />
for what <strong>the</strong>y want. Fur<strong>the</strong>r, as noted<br />
by FAO, efficiently provid<strong>in</strong>g quality<br />
fresh products to <strong>the</strong>se urban markets<br />
usually requires production capacity<br />
be<strong>in</strong>g relatively nearby (FAO,<br />
2009b). A scenario can be envisioned<br />
where regional aquaculture producers<br />
and fishers will want to preferentially<br />
serve markets <strong>in</strong> <strong>the</strong> megacities ra<strong>the</strong>r<br />
than serve distant export customers<br />
with lower value frozen products.<br />
This presumption is supported by recent<br />
U.S. import statistics that <strong>in</strong>dicate<br />
over 75% of fish products entered <strong>the</strong><br />
country frozen and from as far away as<br />
Asia, while fresh fish came from nearby<br />
countries <strong>in</strong> <strong>the</strong> Western Hemisphere<br />
(ERS, 2009).<br />
The Peoples Republic of Ch<strong>in</strong>a’s<br />
rapid transition to a market-based<br />
economy has been extraord<strong>in</strong>ary. The<br />
country’s focus on modernization and<br />
<strong>in</strong>creas<strong>in</strong>g world trade has made it <strong>the</strong><br />
most <strong>in</strong>fluential nation <strong>in</strong> Asia and an<br />
important trad<strong>in</strong>g partner for American<br />
<strong>in</strong>dustry. Ch<strong>in</strong>a also has become<br />
aholderofsignificant amounts of<br />
U.S. currency (foreign exchange reserves)<br />
and national debt, both highly<br />
sensitive political issues (Naisbett and<br />
Naisbett, 2010).<br />
With respect to fishery products<br />
and seafood, Ch<strong>in</strong>a has become a dom<strong>in</strong>ant<br />
player <strong>in</strong> world markets, and <strong>the</strong><br />
country will have a major, long-term<br />
<strong>in</strong>fluence on <strong>the</strong> production and distribution<br />
of seafood around <strong>the</strong> world<br />
(Johnson, 2009). Consider <strong>the</strong>se statistics<br />
about Ch<strong>in</strong>a and <strong>the</strong> global seafood<br />
<strong>in</strong>dustry:<br />
■ Ch<strong>in</strong>a was <strong>the</strong> largest producer of<br />
fisheries products <strong>in</strong> <strong>the</strong> world <strong>in</strong><br />
2006 with a total of 46 mmt:<br />
14.7 mmt (32.5 million pounds)<br />
from capture and 31.4 mmt (69.4<br />
million pounds) from aquaculture.<br />
Total fishery products production<br />
is over six times <strong>the</strong> next lead<strong>in</strong>g<br />
country, India (NMFS, 2009a).<br />
■ Ch<strong>in</strong>a is <strong>the</strong> global leader <strong>in</strong> aquaculture<br />
production, supply<strong>in</strong>g<br />
67% of <strong>the</strong> world supply of fish<br />
and shellfish <strong>in</strong> 2006 and 49% of<br />
<strong>the</strong> value.<br />
■ From 1970 to 2006, Ch<strong>in</strong>a’s aquaculture<br />
production <strong>in</strong>creased at an<br />
annual average of 11.2%. However,<br />
recently <strong>the</strong> growth rate has decl<strong>in</strong>ed<br />
to 5.8% from 17.3% <strong>in</strong> <strong>the</strong><br />
1980s to 14.3% <strong>in</strong> <strong>the</strong> 1990s.<br />
■ S<strong>in</strong>ce 2002, Ch<strong>in</strong>a has been <strong>the</strong><br />
world’s largest exporter of fish and<br />
fishery products, valued at $9.3 billion<br />
<strong>in</strong> 2007 (FAO, 2009b).<br />
With respect to Ch<strong>in</strong>a’s grow<strong>in</strong>g<br />
direct <strong>in</strong>fluence on <strong>the</strong> U.S. seafood <strong>in</strong>dustry,<br />
consider <strong>the</strong>se reported data<br />
(NMFS, 2009a):<br />
May/June 2010 Volume 44 Number 3 13
■ Over <strong>the</strong> period 1998 to 2007, U.S.<br />
imports of fish and seafood from<br />
Ch<strong>in</strong>a <strong>in</strong>creased from $289.5 million<br />
to $1.5 billion.<br />
■ In 2008, Ch<strong>in</strong>a accounted for 22%<br />
of edible and nonedible fishery imports,<br />
valued at $4.1 billion.<br />
■ In terms of edible fishery products<br />
imported <strong>in</strong> 2008, Ch<strong>in</strong>a accounted<br />
for over 523,000 mt, valued<br />
at $2.2 billion.<br />
■ Ch<strong>in</strong>a received 19% of all U.S. fisheries<br />
product exports (edible and<br />
nonedible) valued at $2.5 billion.<br />
With Ch<strong>in</strong>a’s fundamental importance<br />
to global seafood supply and<br />
demand, not only to feed itself but<br />
also to supply major import<strong>in</strong>g<br />
countries like <strong>the</strong> United States, it is<br />
disturb<strong>in</strong>g that <strong>the</strong> United Nations<br />
FAO—<strong>the</strong> keeper of world fishery<br />
and aquaculture statistics—lacks confidence<br />
<strong>in</strong> Ch<strong>in</strong>a’s fishery statistics,<br />
particularly for aquaculture production.<br />
FAO stated <strong>in</strong> 2009, “There are<br />
cont<strong>in</strong>ued <strong>in</strong>dications that capture<br />
fisheries and aquaculture production<br />
statistics for Ch<strong>in</strong>a may be too high<br />
and <strong>the</strong> problem has existed s<strong>in</strong>ce <strong>the</strong><br />
early 90s.” Ch<strong>in</strong>ese officials have recently<br />
<strong>in</strong>dicated <strong>the</strong>y are work<strong>in</strong>g to revise<br />
downward fishery and aquaculture<br />
statistics; for example, <strong>in</strong> 2008 Ch<strong>in</strong>a<br />
reported reduced total fishery and<br />
aquaculture production for 2006 of<br />
more than 10% (FAO, 2009b).<br />
These glar<strong>in</strong>g uncerta<strong>in</strong>ties have serious<br />
implications for <strong>the</strong> predictability<br />
and stability of future seafood imports<br />
to <strong>the</strong> United States.<br />
F<strong>in</strong>ally, <strong>the</strong> world’s seafood importers<br />
are largely supplied by develop<strong>in</strong>g<br />
countries that are <strong>in</strong>herently more<br />
vulnerable to <strong>the</strong> geopolitical events<br />
and bilateral and multilateral disputes<br />
common today. To underscore <strong>the</strong> <strong>in</strong>herent<br />
fragility of supplies, it is estimatedthatupto75%ofglobal<br />
14 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
aquaculture production comes from<br />
millions of small-scale farms, with <strong>the</strong><br />
majority located <strong>in</strong> Asia (FAO,<br />
2009a). Fur<strong>the</strong>r, concerns currently<br />
exist that although Asian production<br />
has rapidly expanded, regulatory standards<br />
that ensure a basic level of compliance<br />
with feed additive usage are<br />
lagg<strong>in</strong>g beh<strong>in</strong>d; that is, small farmers<br />
are often not aware of common food<br />
safety issues (Tan, 2009). For example,<br />
<strong>in</strong> 2007 <strong>the</strong> U.S. Food and Drug Adm<strong>in</strong>istration<br />
announced broader<br />
import controls on all farm raised<br />
aquatic products from Ch<strong>in</strong>a due to residues<br />
from drugs not U.S. approved<br />
(OCA, 2009).<br />
The FAO lists just some major recurr<strong>in</strong>g<br />
issues that can impact <strong>in</strong>ternational<br />
trade <strong>in</strong> fishery products as<br />
follows (FAO, 2009a): (1) <strong>in</strong>troduction<br />
by buyers and <strong>in</strong>ternational retailers<br />
of private standards for food safety<br />
and quality, animal health, environmental<br />
susta<strong>in</strong>ability, and social purposes;<br />
(2) trade disputes, for example,<br />
shrimp, salmon, and catfish.; (3) use of<br />
ecolabels and certification requirements<br />
by retailers; (4) expansion of regional<br />
trade areas and regional and<br />
bilateral trade agreements; and (5) ris<strong>in</strong>g<br />
energy prices and <strong>the</strong>ir impact on<br />
fisheries and aquaculture.<br />
In summary, <strong>the</strong> <strong>in</strong>evitable geopoliticaltensionsovernationalself<strong>in</strong>terest<br />
and global f<strong>in</strong>ancial markets,<br />
trade, energy, human rights, and national<br />
security issues, et al., could frequently<br />
and substantially disrupt <strong>the</strong> flow of future<br />
seafood imports <strong>in</strong>to <strong>the</strong> United<br />
States, with rapid and last<strong>in</strong>g negative<br />
consequences to <strong>the</strong> multibillion dollar,<br />
nationwide seafood economy.<br />
Futurists, such as Lester Brown,<br />
po<strong>in</strong>t to global food security as <strong>the</strong><br />
weak l<strong>in</strong>k <strong>in</strong> successfully feed<strong>in</strong>g <strong>the</strong><br />
world’s grow<strong>in</strong>g population. He states,<br />
“Food security will deteriorate fur<strong>the</strong>r<br />
unless lead<strong>in</strong>g countries collectively<br />
mobilize to stabilize population, stabilize<br />
climate, stabilize aquifers, conserve<br />
soils, and protect cropland” (Brown,<br />
2009). The <strong>in</strong>escapable conclusion is<br />
that future U.S. imports are vulnerable<br />
to major disruption as <strong>the</strong> world negotiates<br />
<strong>the</strong> challenges of achiev<strong>in</strong>g a<br />
susta<strong>in</strong>able <strong>21st</strong> century society,<br />
given <strong>the</strong> importance of <strong>in</strong>ternational<br />
trade <strong>in</strong> seafood; <strong>the</strong> questionable ability<br />
for Asian countries, particularly<br />
Ch<strong>in</strong>a, to meet production projections;<br />
<strong>the</strong> grow<strong>in</strong>g pressures on <strong>the</strong> flow of<br />
products <strong>in</strong> global supply networks;<br />
and <strong>the</strong> dependency of develop<strong>in</strong>g<br />
countries on seafood for basic aquatic<br />
prote<strong>in</strong>. Increased seafood security, def<strong>in</strong>ed<br />
as self-sufficiency to ma<strong>in</strong>ta<strong>in</strong> adequate<br />
supplies for domestic use, should<br />
be targeted as a critical policy issue for<br />
help<strong>in</strong>g ma<strong>in</strong>ta<strong>in</strong> a vibrant and diverse<br />
national economy, a healthy and productive<br />
ocean environment, and a robust<br />
quality of life for Americans.<br />
Consider<strong>in</strong>g U.S. Ocean<br />
Resources for Domestic<br />
Seafood Production<br />
The U.S. Ocean Resource<br />
On March 10, 1983, President<br />
Reagan established by proclamation<br />
an EEZ for America. 6 In effect, <strong>the</strong><br />
EEZ designation puts all liv<strong>in</strong>g and<br />
nonliv<strong>in</strong>g resources between 3 and<br />
200 nautical miles from shore under<br />
<strong>the</strong> primary jurisdiction, management,<br />
and regulation of <strong>the</strong> federal government<br />
(USCOP, 2004).<br />
The U.S. EEZ is <strong>the</strong> largest of any<br />
nation and covers 11.7 million km 2<br />
6 Def<strong>in</strong>ition of EEZ: The EEZ is <strong>the</strong> area that extends<br />
from seaward boundaries of coastal states, usually<br />
3 nautical miles with most states. The exceptions<br />
are Texas, Puerto Rico, and <strong>the</strong> Gulf Coast of Florida<br />
at 9 nautical miles to 200 nautical miles (source:<br />
USCOP, 2004).
(4.5 million square miles), about 50%<br />
more than <strong>the</strong> total land mass of <strong>the</strong><br />
lower 48 states (Pew Oceans Commission,<br />
2003). The area spans a diverse<br />
array of ecosystems from <strong>the</strong> frigid Arctictotropicalmar<strong>in</strong>ehabitats<strong>in</strong><strong>the</strong><br />
Atlantic and Pacific oceans. The EEZ<br />
is subject to a myriad of critical uses<br />
that serve American society, <strong>in</strong>clud<strong>in</strong>g<br />
energy extraction, seafood harvest<strong>in</strong>g,<br />
mar<strong>in</strong>e transportation, national defense,<br />
ocean recreation, and mar<strong>in</strong>e<br />
conservation. Although all <strong>the</strong>se uses<br />
are highly significant, its enormous<br />
size and great habitat diversity suggest<br />
that <strong>the</strong>re are ample resources and<br />
space to enhance exist<strong>in</strong>g uses and,<br />
through proper plann<strong>in</strong>g and sit<strong>in</strong>g,<br />
develop critical new uses for society, for<br />
example, w<strong>in</strong>d energy and open ocean<br />
aquaculture (USCOP, 2004).<br />
Both state mar<strong>in</strong>e waters, which<br />
encompass an estimated additional<br />
84,000 km 2 (32,500 miles 2 ), and <strong>the</strong><br />
EEZ are essential to <strong>the</strong> future of domestic<br />
seafood supplies for America.<br />
In 2008, fishery land<strong>in</strong>gs for edible<br />
and <strong>in</strong>dustrial products were 3.8 mmt<br />
(8.4 billion pounds) valued at $4.4 billion.<br />
Economic benefits of land<strong>in</strong>gs<br />
impact <strong>the</strong> Atlantic, Pacific, and Gulf<br />
coasts as well as Hawaii and <strong>the</strong> U.S.<br />
territories and flag islands. For example,<br />
Alaska led all states <strong>in</strong> value of<br />
land<strong>in</strong>gs with $1.7 billion, followed<br />
by Massachusetts at $400 million,<br />
Ma<strong>in</strong>e at $288 million, Louisiana at<br />
$273 million, and Wash<strong>in</strong>gton at<br />
$250 million. There are 50 major<br />
U.S. ports where commercial fishery<br />
land<strong>in</strong>gs are significant, mov<strong>in</strong>g product<br />
volumes of between 4,545 and<br />
455,000 mt (10 million and 1 billion<br />
pounds) that are valued at between<br />
$10 million and $300 million per<br />
year. These ports are located <strong>in</strong> 16 of<br />
26 U.S. states and territories with<br />
ocean coasts. Moreover, <strong>the</strong> liv<strong>in</strong>g re-<br />
sources <strong>in</strong> <strong>the</strong> EEZ were <strong>the</strong> source<br />
<strong>in</strong> 2008 for approximately 65% of all<br />
fishery land<strong>in</strong>gs <strong>in</strong> <strong>the</strong> United States<br />
(NMFS, 2009a).<br />
Currently, domestic mar<strong>in</strong>e aquaculture<br />
contributes less than 1.5% of<br />
U.S. seafood consumption, and all<br />
production comes from coastal land<br />
sites and nearshore sites <strong>in</strong> state mar<strong>in</strong>e<br />
waters (Forster and Nash, 2008). The<br />
United States has no commercial open<br />
ocean farms <strong>in</strong> <strong>the</strong> EEZ at this time<br />
primarily because of <strong>the</strong> lack of a permitt<strong>in</strong>g<br />
process and leas<strong>in</strong>g regime to<br />
grant and adm<strong>in</strong>ister <strong>the</strong> property<br />
rights needed for <strong>the</strong> private sector to<br />
<strong>in</strong>vest <strong>in</strong> offshore fish farm<strong>in</strong>g (Cic<strong>in</strong>-<br />
Sa<strong>in</strong>, et al., 2005; NOAA, 2008).<br />
As o<strong>the</strong>r nations with ocean coasts<br />
(e.g., England, Ireland, Norway, and<br />
Ch<strong>in</strong>a) but less resource potential actively<br />
move commercial mar<strong>in</strong>e aquaculture<br />
<strong>in</strong>to <strong>the</strong> open ocean (Ryan,<br />
2004; James and Slaski, 2006; Watson<br />
and Drumm, 2007; FAO, 2009b),<br />
America has rema<strong>in</strong>ed hesitant to<br />
move forward. This despite conservative<br />
estimates show<strong>in</strong>g that less than<br />
500 km 2 (less than 0.01% of <strong>the</strong><br />
U.S. EEZ) could produce up to<br />
600,000 mt (1.33 billion pounds) or<br />
more of additional seafood (Nash,<br />
2004). <strong>Mar<strong>in</strong>e</strong> aquaculture proponents<br />
today highlight <strong>the</strong> huge size<br />
and <strong>in</strong>credible habitat diversity of <strong>the</strong><br />
EEZ that offer a great opportunity to<br />
farm a wide range of economically important<br />
mar<strong>in</strong>e species for domestic<br />
markets and export (Nash, 2004;<br />
USDOC, 2007; Forster, 2008).<br />
Federal and Congressional<br />
Efforts to Expand <strong>Mar<strong>in</strong>e</strong><br />
<strong>Aquaculture</strong> Development<br />
In 1999, <strong>the</strong> NOAA of <strong>the</strong><br />
USDOC spearheaded efforts to ex-<br />
pand <strong>the</strong> mar<strong>in</strong>e aquaculture <strong>in</strong>dustry<br />
and particularly to allow commercial<br />
farm<strong>in</strong>g <strong>in</strong> <strong>the</strong> EEZ. These efforts<br />
were catalyzed by an ambitious policy<br />
adopted by USDOC that framed <strong>the</strong><br />
need and potential for aquaculture to<br />
contribute significantly to domestic<br />
seafood supplies by 2025 to <strong>in</strong>clude<br />
<strong>the</strong> follow<strong>in</strong>g: (1) <strong>in</strong>crease <strong>the</strong> value<br />
of domestic aquaculture production<br />
(freshwater and mar<strong>in</strong>e) from $900<br />
million annually to $5 billion; (2) <strong>in</strong>crease<br />
<strong>the</strong> number of jobs <strong>in</strong> aquaculture<br />
from 180,000 to 600,000;<br />
(3) enhance depleted wild fisheries<br />
stocks through aquaculture, <strong>the</strong>reby<br />
<strong>in</strong>creas<strong>in</strong>g <strong>the</strong> value of both commercial<br />
and recreational land<strong>in</strong>gs and improv<strong>in</strong>g<br />
<strong>the</strong> health of U.S. resources;<br />
and (4) <strong>in</strong>crease exports of aquaculture<br />
goods and services from $500 million<br />
to $2.5 billion annually (USDOC,<br />
1999).<br />
Over <strong>the</strong> period 2004 to 2008, a<br />
national dialogue on ocean use and<br />
policy ensued, largely prompted by<br />
publication of comprehensive reports<br />
by <strong>the</strong> <strong>in</strong>dependent Pew Oceans Commission<br />
<strong>in</strong> 2003 and <strong>the</strong> USCOP <strong>in</strong><br />
early 2004, followed by <strong>the</strong> Bush Adm<strong>in</strong>istration’s<br />
U.S. Ocean Action Plan<br />
<strong>in</strong> December 2004. Important components<br />
of <strong>the</strong>se discussions focused on<br />
<strong>the</strong> future of fisheries and <strong>the</strong> role of<br />
mar<strong>in</strong>e aquaculture <strong>in</strong> domestic seafood<br />
production and <strong>in</strong>cluded a need<br />
for a lead federal agency for susta<strong>in</strong>able<br />
mar<strong>in</strong>e aquaculture, a designation of<br />
<strong>the</strong> USDOC with primary responsibility<br />
to ensure offshore aquaculture<br />
develops <strong>in</strong> an environmentally susta<strong>in</strong>able<br />
manner, and <strong>in</strong>troduction by<br />
<strong>the</strong> Adm<strong>in</strong>istration of <strong>the</strong> National<br />
Offshore <strong>Aquaculture</strong> Act of 2005<br />
(S. 1195, although hear<strong>in</strong>gs were held<br />
<strong>in</strong> 2006 <strong>the</strong> bill did not pass), a preparation<br />
of a 10-year plan for <strong>the</strong> NOAA<br />
<strong>Aquaculture</strong> Program <strong>in</strong> 2007, and a<br />
May/June 2010 Volume 44 Number 3 15
submission of ano<strong>the</strong>r offshore aquaculture<br />
bill, entitled “The National<br />
<strong>Aquaculture</strong> Act of 2007” (H.R. 2010<br />
and S. 1609), but aga<strong>in</strong> after hear<strong>in</strong>gs <strong>in</strong><br />
2008, <strong>the</strong> bill did not pass (USCOP,<br />
2004; Bush Adm<strong>in</strong>istration, 2004;<br />
USDOC, 2007).<br />
Real progress <strong>in</strong> national legislation<br />
to encourage commercial development<br />
has been limited. However, <strong>the</strong> constra<strong>in</strong>ts<br />
to and <strong>the</strong> opportunities for<br />
mar<strong>in</strong>e aquaculture were fully described,<br />
and a large community of<br />
stakeholders became better <strong>in</strong>formed.<br />
With President Obama’s election<br />
and <strong>the</strong> appo<strong>in</strong>tment of a new Adm<strong>in</strong>istration<br />
<strong>in</strong> 2009, mar<strong>in</strong>e aquaculture<br />
and ocean farm<strong>in</strong>g <strong>in</strong> <strong>the</strong> EEZ are<br />
aga<strong>in</strong> topics of discussion. The President<br />
began develop<strong>in</strong>g an ocean agenda<br />
and appo<strong>in</strong>ted an Interagency Ocean<br />
Policy Task Force on June 12, 2009,<br />
charged with rapidly formulat<strong>in</strong>g a national<br />
policy for <strong>the</strong> ocean, <strong>the</strong> coasts,<br />
and <strong>the</strong> Great Lakes. Specifically, <strong>the</strong><br />
task force was mandated to develop<br />
recommendations for a framework<br />
for improved federal policy coord<strong>in</strong>ation<br />
and an implementation strategy<br />
to meet objectives of a national ocean<br />
policy, all with<strong>in</strong> 90 days. Fur<strong>the</strong>r,<br />
with<strong>in</strong> 180 days, <strong>the</strong> group was to develop<br />
a framework for coastal and mar<strong>in</strong>e<br />
spatial plann<strong>in</strong>g for federal and<br />
state ocean waters and <strong>the</strong> Great<br />
Lakes to support <strong>the</strong> development of<br />
a national ocean policy (Council on Environmental<br />
Quality [CEQ], 2009a,<br />
2009b).<br />
On September 10, 2009, <strong>the</strong><br />
Ocean Policy Task Force released its<br />
<strong>in</strong>terim report for public comment<br />
describ<strong>in</strong>g a national policy, modifications<br />
to <strong>the</strong> exist<strong>in</strong>g governance structure<br />
and n<strong>in</strong>e categories of action<br />
(CEQ, 2009a, 2009b). Subsequently,<br />
<strong>the</strong> Ocean Policy Task Force released<br />
its required report on mar<strong>in</strong>e spatial<br />
16 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
plann<strong>in</strong>g, entitled “Interim Framework<br />
for Effective Coastal and <strong>Mar<strong>in</strong>e</strong><br />
Spatial Plann<strong>in</strong>g” on December 9,<br />
2009, for public comment. The report<br />
outl<strong>in</strong>ed an <strong>in</strong>novative, stakeholderdriven<br />
process through which <strong>the</strong><br />
federal government will carry out<br />
more <strong>in</strong>tegrated plann<strong>in</strong>g and management<br />
of activities <strong>in</strong> America’s oceans<br />
and <strong>the</strong> Great Lakes and provides an<br />
ambitious 5-year timetable. Although<br />
<strong>the</strong> <strong>in</strong>itial task force report barely mentions<br />
aquaculture, <strong>the</strong> spatial plann<strong>in</strong>g<br />
framework lists a range of 15 social,<br />
economic, and cultural uses for consideration,<br />
<strong>in</strong>clud<strong>in</strong>g aquaculture<br />
(fish, shellfish, and seaweed farm<strong>in</strong>g),<br />
commercial fish<strong>in</strong>g, recreational fish<strong>in</strong>g,<br />
ports and harbors, and traditional<br />
hunt<strong>in</strong>g, fish<strong>in</strong>g, and ga<strong>the</strong>r<strong>in</strong>g (CEQ,<br />
2009b).<br />
It will be important to mar<strong>in</strong>e<br />
aquaculture to see how <strong>the</strong> 2010<br />
Congress prioritizes and supports this<br />
new comprehensive approach to<br />
ocean management. Meanwhile,<br />
o<strong>the</strong>r recent national actions have focused<br />
on actively mov<strong>in</strong>g mar<strong>in</strong>e aquaculture<br />
<strong>in</strong>to <strong>the</strong> EEZ and are briefly<br />
highlighted:<br />
1. In 2009, <strong>the</strong> Gulf Coast Regional<br />
Fisheries Management Council developed<br />
a permit and leas<strong>in</strong>g<br />
process for commercial mar<strong>in</strong>e<br />
aquaculture <strong>in</strong> federal waters of<br />
<strong>the</strong> Gulf of Mexico that awaits implementation<br />
after fur<strong>the</strong>r deliberation<br />
by NOAA to establish a policy<br />
for commercial farm<strong>in</strong>g <strong>in</strong> <strong>the</strong><br />
EEZ. The effort <strong>in</strong>cluded a comprehensive<br />
Programmatic Environmental<br />
Impact Statement and<br />
Management Plan (Gulf Coast Regional<br />
Fisheries Management<br />
Council, 2009).<br />
2. Legislation (H.R. 4363) was submitted<br />
<strong>in</strong> December 2009 to establish<br />
a comprehensive regulatory<br />
framework and research program<br />
for offshore aquaculture development<br />
<strong>in</strong> <strong>the</strong> EEZ that balances environmental,<br />
social, and economic<br />
concerns and focuses on establish<strong>in</strong>g<br />
a regulatory system; authoriz<strong>in</strong>g<br />
<strong>the</strong> Secretary of Commerce to<br />
determ<strong>in</strong>e appropriate locations,<br />
to permit, to regulate, to monitor,<br />
and to enforce offshore aquaculture<br />
activities; requir<strong>in</strong>g <strong>the</strong> Secretary of<br />
Commerce to issue regulations and<br />
permits for offshore aquaculture to<br />
prevent and/or m<strong>in</strong>imize impacts<br />
on <strong>the</strong> mar<strong>in</strong>e ecosystem and fisheries;<br />
and establish<strong>in</strong>g a research<br />
program to guide <strong>the</strong> precautionary<br />
development of offshore aquaculture<br />
(Gov. track, 2009). The<br />
legislation awaits hear<strong>in</strong>gs at this<br />
writ<strong>in</strong>g.<br />
3. NOAA announced <strong>in</strong> December<br />
2009 that it will develop a comprehensive<br />
national policy for susta<strong>in</strong>able<br />
mar<strong>in</strong>e aquaculture <strong>in</strong> federal<br />
waters. The policy will enable domestic<br />
aquaculture, which adds to<br />
<strong>the</strong> U.S. seafood supply, supports<br />
important commercial and recreational<br />
fisheries, develops coord<strong>in</strong>ated<br />
federal standards for permitt<strong>in</strong>g<br />
facilities <strong>in</strong> federal waters, and formulates<br />
strategies to provide <strong>the</strong><br />
scientific <strong>in</strong>formation needed for<br />
permitt<strong>in</strong>g decisions. Stakeholder<br />
<strong>in</strong>put will be sought <strong>in</strong> 2010<br />
(NOAA, 2009b).<br />
Current Issues <strong>in</strong> U.S.<br />
Commercial Offshore<br />
<strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
Development<br />
National surveys document<strong>in</strong>g <strong>the</strong><br />
changes <strong>in</strong> <strong>the</strong> number of farms and<br />
farm acreage <strong>in</strong> <strong>the</strong> U.S. aquaculture<br />
<strong>in</strong>dustry between 1998 and 2005
lead to several conclusions about <strong>the</strong><br />
potential direction of future development<br />
(National Agricultural Statistics<br />
Service, 2000, 2006). Freshwater acreage<br />
is grow<strong>in</strong>g slowly, and future <strong>in</strong>creases<br />
<strong>in</strong> production will largely<br />
come from <strong>in</strong>tensify<strong>in</strong>g production<br />
on exist<strong>in</strong>g land-based farms ra<strong>the</strong>r<br />
than major site expansions and build<strong>in</strong>g<br />
new farms. Nearshore mar<strong>in</strong>e<br />
farm<strong>in</strong>g (ma<strong>in</strong>ly bivalve shellfish) is <strong>in</strong>creas<strong>in</strong>g<br />
rapidly, and fur<strong>the</strong>r expansion<br />
of commercial mar<strong>in</strong>e aquaculture <strong>in</strong>to<br />
open ocean locations offers <strong>the</strong> greatest<br />
potential for large-scale growth because<br />
of less competition for use of resources<br />
and <strong>the</strong> large area available<br />
(Corb<strong>in</strong>, 2007a). Moreover, accord<strong>in</strong>g<br />
to <strong>the</strong> USCOP, locat<strong>in</strong>g aquaculture<br />
activities fur<strong>the</strong>r offshore will reduce<br />
conflicts over <strong>the</strong> visibility of facilities<br />
from land, be less <strong>in</strong>trusive to nearshore<br />
capture fisheries and recreational<br />
activities, and have fewer environmental<br />
impacts (USCOP, 2004).<br />
Leas<strong>in</strong>g federal waters for commercial<br />
aquaculture has been a controversial<br />
subject <strong>in</strong> recent years, rais<strong>in</strong>g a<br />
variety of issues for discussion and consensus<br />
build<strong>in</strong>g among opponents and<br />
proponents. Among <strong>the</strong> most difficult<br />
to address has been <strong>the</strong> potential for<br />
negative environmental impacts of<br />
large-scale mar<strong>in</strong>e farm<strong>in</strong>g <strong>in</strong> <strong>the</strong><br />
open ocean sett<strong>in</strong>g of <strong>the</strong> EEZ. The<br />
most frequently mentioned concerns<br />
by opponents <strong>in</strong>clude escapes of<br />
farmed species and mix<strong>in</strong>g with wild<br />
populations, disease and parasite management<br />
and <strong>the</strong> potential for <strong>in</strong>fection<br />
of wild populations, use of fishmeal as<br />
a major prote<strong>in</strong> source <strong>in</strong> fish feeds<br />
impact<strong>in</strong>g <strong>the</strong> source fisheries, and pollution<br />
potential and <strong>the</strong> need for standards<br />
for acceptable change <strong>in</strong> <strong>the</strong><br />
quality of <strong>the</strong> water column and substrate<br />
<strong>in</strong> and around farms (Lubchenko,<br />
2003; MATF, 2007).<br />
The research community and <strong>the</strong><br />
<strong>in</strong>dustry have made significant efforts<br />
to study <strong>the</strong>se recurr<strong>in</strong>g concerns and<br />
how <strong>the</strong>y can be successfully managed.<br />
There have been documented positive<br />
reports of negligible environmental<br />
impacts from several multiyear offshore<br />
research and commercial mar<strong>in</strong>e<br />
farm<strong>in</strong>g projects <strong>in</strong> Hawaii, Puerto<br />
Rico, and New Hampshire, with comb<strong>in</strong>ed<br />
operat<strong>in</strong>g experience of over<br />
20 years (<strong>Aquaculture</strong> Plann<strong>in</strong>g and<br />
Advocacy, 2009; Kona Blue Water<br />
Farms, 2009; Alston et al., 2005;<br />
Langan, 2007). Proponents believe<br />
that <strong>the</strong> results from <strong>the</strong>se projects,<br />
which <strong>in</strong>clude comprehensive environmental<br />
monitor<strong>in</strong>g (e.g., water column<br />
and substrate quality, feed<strong>in</strong>g and feed<br />
conversion, stock health and escapes),<br />
and o<strong>the</strong>rs from around <strong>the</strong> world<br />
(Ryan, 2004) support <strong>the</strong> conclusion<br />
that <strong>the</strong> potential for negative environmental<br />
impacts from offshore and<br />
open ocean aquaculture is very manageable<br />
through proper sit<strong>in</strong>g and<br />
farm operation (e.g., application of<br />
well-known <strong>in</strong>dustry best management<br />
practices). It is suggested that<br />
sufficient empirical and scientific <strong>in</strong>formation<br />
exists to select open ocean<br />
sites with appropriate oceanographic<br />
conditions (e.g., sufficient current for<br />
mix<strong>in</strong>g and substrate for anchor<strong>in</strong>g)<br />
and operate a f<strong>in</strong>ite number of largescale<br />
farms to demonstrate that today’s<br />
“off <strong>the</strong> shelf ” technologies and available<br />
native-to-<strong>the</strong>-region species are<br />
scalable and can be susta<strong>in</strong>ably managed.<br />
For example, work by Renzel<br />
et al. (2007) and <strong>the</strong> Scottish Association<br />
of <strong>Mar<strong>in</strong>e</strong> Science (2009) on model<strong>in</strong>g<br />
potential site impacts of ocean<br />
farm<strong>in</strong>g and by Nash et al. (2005) and<br />
Rust (2007) on ecological risk management<br />
can be highlighted for guidance.<br />
What is lack<strong>in</strong>g at this stage, accord<strong>in</strong>g<br />
to <strong>the</strong> nascent <strong>in</strong>dustry, is ap-<br />
plication of this <strong>in</strong>formation to<br />
establish a workable <strong>in</strong>terim permitt<strong>in</strong>g<br />
and leas<strong>in</strong>g process for federal<br />
waters to allow <strong>the</strong> private sector to<br />
demonstrate large-scale commercial<br />
farm<strong>in</strong>g <strong>in</strong> <strong>in</strong>terested regions. Model<br />
processes to base an <strong>in</strong>terim EEZ permitt<strong>in</strong>g<br />
and leas<strong>in</strong>g program for cage<br />
culture have been suggested for federal<br />
waters (Cic<strong>in</strong>-Sa<strong>in</strong> et al., 2005) and are<br />
operat<strong>in</strong>g <strong>in</strong> state waters <strong>in</strong> Ma<strong>in</strong>e and<br />
Hawaii, which <strong>in</strong>clude environmental<br />
assessment of <strong>the</strong> site, stakeholder<br />
<strong>in</strong>put, and environmental monitor<strong>in</strong>g<br />
plans (MDMR, 2009; Corb<strong>in</strong>,<br />
2007b). Us<strong>in</strong>g properly sited demonstration<br />
farms, such as <strong>the</strong> 24-cage<br />
fish culture project be<strong>in</strong>g proposed by<br />
Hubbs-SeaWorld Research Institute<br />
5 miles offshore <strong>in</strong> <strong>the</strong> Sou<strong>the</strong>rn California<br />
Bight (MCRI, 2008), federal<br />
agencies could require monitor<strong>in</strong>g<br />
and collect <strong>in</strong>formation from operat<strong>in</strong>g<br />
farms. In consultation with affected<br />
agencies, states, <strong>in</strong>dustry, and<br />
<strong>the</strong> affected public, this <strong>in</strong>formation<br />
could be used to beg<strong>in</strong> <strong>the</strong> process of<br />
promulgat<strong>in</strong>g standardized regulatory<br />
and leas<strong>in</strong>g processes and environmental<br />
requirements, while nationwide <strong>in</strong>tegrated<br />
spatial plann<strong>in</strong>g is carried out<br />
for federal and state waters. In o<strong>the</strong>r<br />
words, a proactive, adaptive management,<br />
and place-based plann<strong>in</strong>g<br />
approach could be used to move commercial<br />
mar<strong>in</strong>e aquaculture <strong>in</strong>to <strong>the</strong><br />
EEZ <strong>in</strong> a timely manner to address<br />
<strong>the</strong> loom<strong>in</strong>g U.S. seafood supply gap<br />
and make it susta<strong>in</strong>able (Corb<strong>in</strong> and<br />
Young, 1997).<br />
Conclusions<br />
The production, distribution, and<br />
use of edible and nonedible fisheries<br />
products are <strong>in</strong>creas<strong>in</strong>gly important<br />
to <strong>the</strong> expansive and diverse U.S. economy.<br />
Seafood is a multibillion dollar<br />
May/June 2010 Volume 44 Number 3 17
<strong>in</strong>dustry that touches a vast majority of<br />
<strong>the</strong> American population and significantly<br />
affects <strong>the</strong>ir quality of life. The<br />
seafood/fisheries economy impacts<br />
every state and particularly <strong>the</strong> numerous<br />
communities along <strong>the</strong> U.S.<br />
coasts. Domestic demand for seafood<br />
is projected to <strong>in</strong>crease <strong>in</strong> <strong>the</strong> next 10<br />
to 20 years, as <strong>in</strong>dicated by <strong>the</strong> clear<br />
trends for <strong>in</strong>creas<strong>in</strong>g population, per<br />
capita consumption, and importation<br />
of products.<br />
Currently, 84% of U.S. seafood<br />
consumption is supplied by imports,<br />
largely from develop<strong>in</strong>g countries <strong>in</strong><br />
Asia, and this dependency is expected<br />
to cont<strong>in</strong>ue and grow unless <strong>the</strong>re is<br />
greater public and especially private <strong>in</strong>vestment<br />
(<strong>the</strong> government does not<br />
create bus<strong>in</strong>esses and jobs, <strong>the</strong> private<br />
sector does) <strong>in</strong>to research and development<br />
to <strong>in</strong>crease domestic production.<br />
Domestic supplies from commercial<br />
fisheries have, more or less, leveled<br />
off, and freshwater and mar<strong>in</strong>e aquaculture<br />
(mostly freshwater species like<br />
catfish and trout) have grown steadily<br />
but supply only 7% of consumption.<br />
<strong>Mar<strong>in</strong>e</strong> aquaculture has <strong>the</strong> most potential<br />
for large-scale expansion but<br />
currently supplies only 1.5% of domestic<br />
consumption.<br />
Conservatively, projections <strong>in</strong>dicate<br />
that <strong>the</strong> United States will need<br />
between 0.29 mmt (641 million<br />
pounds) and 0.76 mmt (1.68 billion<br />
pounds) more seafood <strong>in</strong> 2020 and between<br />
0.52 mmt (1.15 billion pounds)<br />
and1.05mmt(2.32billionpounds)<br />
more <strong>in</strong> 2030. The Adm<strong>in</strong>istration,<br />
<strong>the</strong> Congress, and <strong>the</strong> American public<br />
can choose to cont<strong>in</strong>ue to rely on<br />
imports or deliberately expand mar<strong>in</strong>e<br />
aquaculture and aquacultureenhanced<br />
fisheries, particularly<br />
through establish<strong>in</strong>g commercial<br />
farms <strong>in</strong> <strong>the</strong> EEZ and stock enhancement<br />
programs to revitalize econom-<br />
18 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
ically important recreational and<br />
commercial mar<strong>in</strong>e fisheries.<br />
Meet<strong>in</strong>g projected American seafood<br />
needs largely with imports is considered<br />
a “risky proposition” over <strong>the</strong><br />
long term, with <strong>the</strong> likelihood that<br />
growth projections for global aquaculture<br />
will not be met and <strong>the</strong> near- and<br />
long-term high volatility of <strong>the</strong> <strong>in</strong>ternational<br />
marketplace for seafood products.<br />
Major reasons for this concern<br />
<strong>in</strong>clude <strong>the</strong> follow<strong>in</strong>g:<br />
1. The rapidly chang<strong>in</strong>g demographics<br />
<strong>in</strong> develop<strong>in</strong>g countries will affect<br />
global seafood distribution<br />
and consumption patterns. Increas<strong>in</strong>g<br />
population and standards<br />
of liv<strong>in</strong>g <strong>in</strong> <strong>the</strong>se countries will<br />
put pressure on supply distribution<br />
channels to <strong>the</strong> United States and<br />
lead to greater regional competition<br />
for products <strong>in</strong> both developed and<br />
develop<strong>in</strong>g countries.<br />
2. The strong urbanization trend of<br />
<strong>the</strong> world population is likely to<br />
drastically impact how seafood is<br />
distributed, as products are directed<br />
to urban population centers<br />
with<strong>in</strong> regions. A scenario is suggested<br />
where regional capture and<br />
culture seafood providers will<br />
preferentially concentrate on fill<strong>in</strong>g<br />
nearby urban consumer preferences<br />
for high-quality, fresh<br />
products.<br />
3. ThedramaticriseofCh<strong>in</strong>aasa<br />
world economic power and a major<br />
seafood producer, consumer,<br />
exporter, and importer will cont<strong>in</strong>ue<br />
to significantly <strong>in</strong>fluence <strong>the</strong> flow<br />
of products <strong>in</strong> <strong>in</strong>ternational trade.<br />
Ch<strong>in</strong>a’s unpredictable political<br />
shifts <strong>in</strong> domestic and trade policies<br />
and its questionable fisheries and<br />
aquaculture production capacity<br />
create uncerta<strong>in</strong>ty that it can feed<br />
its grow<strong>in</strong>g population and expand<strong>in</strong>g<br />
middle class while ma<strong>in</strong>-<br />
ta<strong>in</strong><strong>in</strong>g its <strong>in</strong>creas<strong>in</strong>gly important<br />
role as exporter to <strong>the</strong> United<br />
States.<br />
4. Develop<strong>in</strong>g countries, <strong>the</strong> predom<strong>in</strong>ant<br />
source of seafood supply and<br />
exports <strong>in</strong> <strong>in</strong>ternational trade, are<br />
much more vulnerable to <strong>the</strong> recurr<strong>in</strong>g<br />
geopolitical events and controversies<br />
that will mark <strong>the</strong> <strong>21st</strong><br />
century world’s pathtoasusta<strong>in</strong>able<br />
future (Friedman, 2008;<br />
Brown, 2009). International f<strong>in</strong>ancial,<br />
energy, human rights, homeland<br />
security, trade policy, food<br />
safety, and o<strong>the</strong>r issues can have<br />
sudden significant and last<strong>in</strong>g disruptive<br />
impacts on <strong>the</strong> <strong>in</strong>ternational<br />
seafood trade.<br />
America has <strong>the</strong> largest EEZ <strong>in</strong> <strong>the</strong><br />
world, with enormous potential for develop<strong>in</strong>g<br />
susta<strong>in</strong>able commercial open<br />
ocean aquaculture of many economically<br />
important species. Likewise, clos<strong>in</strong>g<br />
<strong>the</strong> life cycles of important mar<strong>in</strong>e<br />
species would allow greater use of<br />
aquaculture technologies as an important<br />
tool to enhance sources of seafood<br />
from coastal and ocean capture fisheries<br />
through <strong>in</strong>creased stock enhancement.<br />
With greater utilization of <strong>the</strong><br />
EEZ,multipleuseof<strong>the</strong>resource<br />
and o<strong>the</strong>r issues will occur and need<br />
to be resolved at <strong>the</strong> site determ<strong>in</strong>ation<br />
stage. America’s ocean space is enormous,<br />
and conservative estimates <strong>in</strong>dicate<br />
open ocean aquaculture alone<br />
could produce significant amounts of<br />
additional seafood (Nash, 2004).<br />
The management guru Peter<br />
Drucker has suggested, “<strong>Aquaculture</strong>,<br />
not <strong>the</strong> Internet, represents <strong>the</strong> most<br />
promisng <strong>in</strong>vestment opportunity <strong>in</strong><br />
<strong>the</strong> <strong>21st</strong> <strong>Century</strong>.” (Drucker, 1999)<br />
Prompted by <strong>the</strong> recognized opportunities<br />
and several comprehensive reports<br />
on ocean policy and use, legislation<br />
has been proposed <strong>in</strong> Congress to expand<br />
mar<strong>in</strong>e aquaculture research
and development, particularly <strong>in</strong> <strong>the</strong><br />
EEZ.Notably,<strong>the</strong>ObamaAdm<strong>in</strong>istration<br />
has taken a broadened, multiple<br />
use approach to ocean plann<strong>in</strong>g,<br />
policy, and management. <strong>Mar<strong>in</strong>e</strong><br />
aquaculture and fisheries are among<br />
<strong>the</strong> proposed topics for this expanded,<br />
multistakeholder discussion of plann<strong>in</strong>g<br />
and manag<strong>in</strong>g a myriad of uses<br />
of America’s oceans, particularly <strong>the</strong><br />
EEZ.<br />
The critical mar<strong>in</strong>e aquaculture development<br />
issues for stakeholder consensus<br />
build<strong>in</strong>g <strong>in</strong>clude identification<br />
of appropriate sites, control of stock escapes,<br />
disease prevention and management<br />
protocols, reduction <strong>in</strong> <strong>the</strong> use of<br />
fish meal and oil <strong>in</strong> stock diets, and development<br />
of environmental standards<br />
to control potential pollution. It is<br />
suggested that a great deal of pert<strong>in</strong>ent<br />
scientific <strong>in</strong>formation and empirical<br />
evidence has been generated <strong>in</strong> <strong>the</strong><br />
past 10 years that allows detailed assessment<br />
and acceptable predictability<br />
for site specific impacts of farm<strong>in</strong>g,<br />
hence identification of environmentally<br />
suitable sites. This database provides an<br />
<strong>in</strong>formed basis for establish<strong>in</strong>g an <strong>in</strong>terim<br />
ocean permitt<strong>in</strong>g and leas<strong>in</strong>g program<br />
for <strong>the</strong> EEZ that can evolve to a<br />
standardized process based on establish<strong>in</strong>g<br />
and monitor<strong>in</strong>g a f<strong>in</strong>ite number of<br />
regional commercial demonstration<br />
farms. The <strong>in</strong>terim permitt<strong>in</strong>g/leas<strong>in</strong>g<br />
effort to allow <strong>the</strong> private sector to<br />
spearhead progress should be complemented<br />
by <strong>in</strong>creased federal <strong>in</strong>vestment<br />
<strong>in</strong> develop<strong>in</strong>g commercial-scale<br />
mar<strong>in</strong>e aquaculture technologies for<br />
cultureof species important to farm<strong>in</strong>g<br />
and aquaculture-enhanced mar<strong>in</strong>e<br />
fisheries (Browdy and Hargreaves,<br />
2009).<br />
Greater seafood self-sufficiency and<br />
security is required to susta<strong>in</strong>ably and reliably<br />
fill America’s grow<strong>in</strong>gdemand<br />
for seafood <strong>in</strong> a global marketplace.<br />
U.S. imports will become more sensitive<br />
to supply disruption due to <strong>in</strong>creas<strong>in</strong>g<br />
geopolitical tensions and<br />
major demographic and development<br />
trends <strong>in</strong> both <strong>the</strong> developed and <strong>the</strong><br />
develop<strong>in</strong>g worlds. Expand<strong>in</strong>g mar<strong>in</strong>e<br />
aquaculture to susta<strong>in</strong>ably farm <strong>the</strong> sea<br />
and <strong>in</strong>vest<strong>in</strong>g <strong>in</strong> aquaculture-enhanced<br />
fisheries management to rebuild and<br />
ma<strong>in</strong>ta<strong>in</strong> recreational and commercial<br />
stocks can significantly <strong>in</strong>crease domestic<br />
seafood supplies. It also will<br />
provide important job and <strong>in</strong>frastructure<br />
revitalization opportunities<br />
for <strong>the</strong> national economy and many<br />
coastal communities.<br />
The <strong>in</strong>escapable conclusion to be<br />
drawn from this broad review of history,<br />
current status, and future of <strong>the</strong><br />
U.S. seafood “oceanscape” is that environmentally<br />
susta<strong>in</strong>able, economically<br />
viable, and community-accepted expansion<br />
of mar<strong>in</strong>e aquaculture can<br />
and should move forward now. Industry<br />
expansion <strong>in</strong>to <strong>the</strong> EEZ should<br />
not wait for completion of <strong>in</strong>tegrated,<br />
nationwide mar<strong>in</strong>e spatial plann<strong>in</strong>g<br />
of <strong>the</strong> ocean environment, a process<br />
which could take many years to complete.<br />
There is an urgent need for <strong>the</strong><br />
Congress and NOAA to take action<br />
to <strong>in</strong>crease domestic fish and shellfish<br />
supplies through expansion of mar<strong>in</strong>e<br />
aquaculture to bolster <strong>the</strong> seafood <strong>in</strong>dustry<br />
to satisfy its many millions of<br />
customers.<br />
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<strong>in</strong> <strong>the</strong> new millennium. In: <strong>Aquaculture</strong><br />
<strong>in</strong> <strong>the</strong> New Millennium, Technical<br />
Proceed<strong>in</strong>gs of <strong>the</strong> Conference on <strong>Aquaculture</strong><br />
<strong>in</strong> <strong>the</strong> Third Millennium, pp. 431-459.<br />
Bangkok, Thailand: Network of <strong>Aquaculture</strong><br />
Centres <strong>in</strong> Asia-Pacific and UNFAO.<br />
Tan, D. 2009. Asia: Catch<strong>in</strong>g Up with Its<br />
Own Production. Int. Aqua Feed. 12(6):10-12.<br />
U.S. Census Bureau. 2009. Population Div.<br />
Available at: http://www.census.gov (accessed<br />
November 2009).<br />
U.S. Commission on Ocean Policy. 2004.<br />
An Ocean Bluepr<strong>in</strong>t for <strong>the</strong> <strong>21st</strong> <strong>Century</strong>.<br />
Wash<strong>in</strong>gton, DC: USCOP. 610 pp.<br />
U.S. Department of Commerce. 1999.<br />
<strong>Aquaculture</strong> Policy. Wash<strong>in</strong>gton, DC:<br />
USDOC. 2 pp.<br />
U.S. Department of Commerce. 2007.<br />
NOAA 10-Year Plan for <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong>.<br />
Wash<strong>in</strong>gton, DC: NOAA, USDOC, 24 pp.<br />
Watson, L., Drumm, A. eds. 2007. Offshore<br />
<strong>Aquaculture</strong> Development <strong>in</strong> Ireland—‘Next<br />
Steps.’ Dubl<strong>in</strong>, Ireland: Board Iascaigh, Uhara<br />
and <strong>Mar<strong>in</strong>e</strong> Institute, 35 pp.<br />
World Wildlife Fund. 2009. Certification.<br />
Available at: http://www.worldwildlife.org/<br />
cci/aquacultureprojects1.cfm (accessed<br />
December 2009).<br />
May/June 2010 Volume 44 Number 3 21
PAPER<br />
Site Selection Criteria for Open<br />
Ocean <strong>Aquaculture</strong><br />
AUTHORS<br />
Daniel D. Benetti<br />
Rosenstiel School of <strong>Mar<strong>in</strong>e</strong><br />
and Atmospheric Science,<br />
University of Miami<br />
Gabriel I. Benetti<br />
School of Bus<strong>in</strong>ess Adm<strong>in</strong>istration,<br />
University of Miami<br />
José A. Rivera<br />
HC-02, Box 1736, Boquerón,<br />
Puerto Rico<br />
Bruno Sardenberg<br />
Rosenstiel School of <strong>Mar<strong>in</strong>e</strong><br />
and Atmospheric Science,<br />
University of Miami<br />
Brian O’Hanlon<br />
Open Blue Sea Farms LLC<br />
Introduction<br />
Recent technological advances <strong>in</strong><br />
offshore cage systems allow for <strong>the</strong> development<br />
of aquaculture operations<br />
<strong>in</strong> <strong>the</strong> open ocean. This offshore <strong>in</strong>dustryisrapidlyexpand<strong>in</strong>gthroughout<strong>the</strong><br />
world. Indeed, dur<strong>in</strong>g <strong>the</strong> past 20–<br />
30 years, <strong>the</strong> salmon <strong>in</strong>dustry has driven<br />
such technological advances, reach<strong>in</strong>g<br />
a po<strong>in</strong>t where state-of-<strong>the</strong>-art aquaculture<br />
cages with 100 m of diameter<br />
or more, capital cost under US$7/m 3 ,<br />
and widespread applications have been<br />
extensively exposed to high-energy environments<br />
(Scott and Muir, 2000).<br />
The technology is <strong>in</strong> place, as over<br />
<strong>the</strong> past decade a variety of modern<br />
submersible, semisubmersible, and<br />
float<strong>in</strong>g cages have been designed<br />
and built to “conform” with waves<br />
and strong currents associated with <strong>the</strong><br />
22 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
ABSTRACT<br />
With aquaculture steadily expand<strong>in</strong>g, <strong>the</strong> need for suitable space has been followed<br />
by <strong>the</strong> development of more efficient, cost-effective, and environmentally susta<strong>in</strong>able<br />
methodologies. Avoid<strong>in</strong>g possible conflicts between <strong>the</strong> development of<br />
commercial aquaculture operations and <strong>the</strong> environmental impact <strong>in</strong> coastal areas,<br />
utiliz<strong>in</strong>g <strong>the</strong> offshore environment offers <strong>the</strong> greatest potential for expansion of <strong>the</strong><br />
<strong>in</strong>dustry <strong>in</strong> most regions throughout <strong>the</strong> world. Although currents and greater depths<br />
generally <strong>in</strong>crease <strong>the</strong> assimilation capacity and energy of <strong>the</strong> offshore environment<br />
and offer many advantages for aquaculture, a number of challenges associated with<br />
develop<strong>in</strong>g any activity <strong>in</strong> <strong>the</strong> open ocean environment must be taken <strong>in</strong>to consideration.<br />
This article summarizes <strong>the</strong>se advantages and challenges, focus<strong>in</strong>g on <strong>the</strong> first<br />
and most crucial step for project development: site selection criteria for open ocean<br />
aquaculture. Although most of <strong>the</strong> concepts and criteria are common to o<strong>the</strong>r mar<strong>in</strong>e<br />
net pen aquaculture operations, we review and present those conditions that are <strong>in</strong>herent<br />
to <strong>the</strong> open ocean environment and must be considered before develop<strong>in</strong>g any<br />
offshore aquaculture activity. These encompass basic premises; assumptions; logistics;<br />
<strong>in</strong>frastructure; availability of manpower, services, and materials; legal framework;<br />
socioeconomic and political issues; and oceanographic, biological, environmental, and<br />
technological criteria. There are no def<strong>in</strong>ed set of criteria, as most are <strong>in</strong>teract<strong>in</strong>g and<br />
not fixed but <strong>in</strong>terdependent (e.g., depth vs. current velocity). However, suitable sites<br />
must meet basic crucial standards summarized here.<br />
Site selection is one of <strong>the</strong> most important decisions for <strong>the</strong> establishment of a<br />
fish farm operation. Satellite images, hydrographic charts, maps, Google Earth, and<br />
Geographic Information Systems can all provide important <strong>in</strong>formation for prelim<strong>in</strong>ary<br />
work on site assessment; however, a very careful <strong>in</strong> situ survey is mandatory<br />
to evaluate <strong>the</strong> suitability of <strong>the</strong> area.<br />
Keywords: Open ocean aquaculture, Offshore fish farm<strong>in</strong>g, Selection criteria for<br />
ocean fish farm<strong>in</strong>g<br />
high-energy environment generally<br />
associated to offshore areas.<br />
In addition to <strong>the</strong> atta<strong>in</strong>able benefit<br />
of higher potential profits, offshore<br />
aquaculture may provide <strong>the</strong> benefits<br />
of (1) overall reduction <strong>in</strong> conflicts<br />
with o<strong>the</strong>r users and <strong>in</strong> objections<br />
from adjacent landowners, (2) avoidance<br />
of <strong>the</strong> ecological carry<strong>in</strong>g capacity<br />
limitations of <strong>in</strong>shore waters,<br />
(3) access to larger volumes of highquality<br />
water for f<strong>in</strong>fish or filter-<br />
feed<strong>in</strong>g organisms, (4) reduction of<br />
overall ecological impacts, (5) possible<br />
reduction of regulatory and permit<br />
requirements, and (6) ability to culture<br />
high-value, open ocean species<br />
(Stickney and McVey, 2002). Although<br />
<strong>the</strong> economical feasibility of<br />
such operations is still be<strong>in</strong>g evaluated,<br />
<strong>the</strong> potential benefits described signal<br />
<strong>the</strong> feasibility of rais<strong>in</strong>g a variety of<br />
mar<strong>in</strong>e f<strong>in</strong>fish species <strong>in</strong> offshore environments<br />
to <strong>in</strong>crease production while
educ<strong>in</strong>g environmental impacts. Important<br />
reviews on nearshore and open<br />
ocean cage aquaculture are provided<br />
by Beveridge (2004), Bridger and<br />
Costa-Pierce (2003), and Halwart<br />
et al. (2007).<br />
Many exist<strong>in</strong>g open ocean aquaculture<br />
operations are currently located<br />
with<strong>in</strong> 3 miles from shore and thus<br />
shoreward from <strong>the</strong> Exclusive Economic<br />
Zone (EEZ). EEZ is def<strong>in</strong>ed as <strong>the</strong> area<br />
extend<strong>in</strong>g from 3 to 200 nautical miles<br />
of coastal states <strong>in</strong> most countries (with<br />
<strong>the</strong> exceptions of Texas, Puerto Rico,<br />
and Gulf Coast of Florida <strong>in</strong> <strong>the</strong> United<br />
States) (U.S. Commission on Ocean<br />
Policy, 2004). However, <strong>the</strong>re are<br />
plans for expand<strong>in</strong>g <strong>the</strong>se activities to<br />
<strong>the</strong> EEZ’s offshore areas <strong>in</strong> several<br />
countries, <strong>in</strong>clud<strong>in</strong>g <strong>the</strong> United States.<br />
None<strong>the</strong>less, because of greater depth,<br />
stronger currents, and distance from<br />
shore, environmental impacts potentially<br />
associated with aquaculture <strong>in</strong> coastal<br />
areas are expected to be considerably<br />
lower <strong>in</strong> <strong>the</strong> open ocean, suggest<strong>in</strong>g<br />
that offshore cage systems are among<br />
<strong>the</strong> most environmentally friendly methods<br />
for commercial mar<strong>in</strong>e fish culture.<br />
Before <strong>the</strong> establishment of any<br />
fish farm<strong>in</strong>g operation nearshore or<br />
offshore us<strong>in</strong>g float<strong>in</strong>g or submerged<br />
cage or pen systems, a site assessment<br />
must be conducted to carefully evaluate<br />
parameters related to <strong>in</strong>frastructure, topography,<br />
bathymetry, meteorology,<br />
annual ranges of water quality parameters,<br />
and environmental and biological<br />
<strong>in</strong>formation as well as <strong>the</strong> legal<br />
framework. Most criteria also apply<br />
for sit<strong>in</strong>g land-based facilities such as<br />
hatcheries, which are required to support<br />
cage culture operations.<br />
Basic Premises<br />
■ There is no perfect site. Site selection<br />
is a compromise and a process<br />
of elim<strong>in</strong>ation, <strong>in</strong> which <strong>the</strong> major-<br />
ity of areas <strong>in</strong>itially identified as<br />
suitable are generally elim<strong>in</strong>ated because<br />
of user conflicts.<br />
■ Depend<strong>in</strong>g on project size, level of<br />
<strong>in</strong>vestment, and timeframe for development,<br />
it may be necessary to<br />
create <strong>in</strong>frastructure.<br />
Thesuccessof<strong>the</strong>operationwill<br />
depend to a large extent on a thorough<br />
site survey and proper assessment with<br />
regard to project development. Site<br />
selection is done through a process of<br />
elim<strong>in</strong>ation of areas of conflict<strong>in</strong>g<br />
uses. The process generally starts with<br />
<strong>the</strong> identification of a general area that<br />
is potentially <strong>in</strong>terest<strong>in</strong>g and suitable.<br />
Themostsensiblewayofgett<strong>in</strong>g<br />
started is look<strong>in</strong>g at available maps,<br />
charts, and satellite images or on Google<br />
Earth. Geographic Information Systems<br />
(GIS) and remote sens<strong>in</strong>g and<br />
mapp<strong>in</strong>g have become essential tools<br />
<strong>in</strong> site survey<strong>in</strong>g, development, and<br />
management of open ocean aquaculture<br />
(Figures 1A and 1B). Extensive literature<br />
is available on <strong>the</strong> use of GIS,<br />
remote sens<strong>in</strong>g/mapp<strong>in</strong>g, and monitor<strong>in</strong>g<br />
models <strong>in</strong> aquaculture (Ervik et al.,<br />
1997; Hansen et al., 2001; Kapetsky<br />
and Aguilar-Majarrez, 2007; Kiefer<br />
et al., 2008; Pérez et al., 2002; Rensel<br />
et al., 2006; Stigebrandt et al., 2004).<br />
Once all conflict<strong>in</strong>g uses of <strong>the</strong> area<br />
are elim<strong>in</strong>ated and <strong>the</strong> site is identified,<br />
detailed studies must be carried out<br />
<strong>in</strong> situ. The process can be compared<br />
withassembl<strong>in</strong>gapuzzle,whereall<br />
pieces must be identified prior to development,<br />
and <strong>in</strong>dividual factors<br />
must be carefully analyzed and comb<strong>in</strong>ed<br />
to estimate <strong>the</strong> whole picture.<br />
However, one should keep <strong>in</strong> m<strong>in</strong>d<br />
that <strong>the</strong>re is no perfect site and compromis<strong>in</strong>g<br />
is required more often than not.<br />
For example, an o<strong>the</strong>rwise perfect site<br />
from <strong>the</strong> biological standpo<strong>in</strong>t may<br />
lack basic <strong>in</strong>frastructure support. In<br />
this case, depend<strong>in</strong>g on <strong>the</strong> size of <strong>the</strong><br />
project, <strong>the</strong> availability of resources,<br />
and <strong>the</strong> timel<strong>in</strong>e, a viable alternative<br />
is to create <strong>the</strong> necessary <strong>in</strong>frastructure.<br />
To evaluate <strong>the</strong> whole picture, one<br />
can create a matrix by establish<strong>in</strong>g<br />
different weights to different <strong>in</strong>puts<br />
regard<strong>in</strong>g <strong>the</strong>ir relevance <strong>in</strong> <strong>the</strong> respective<br />
process, and <strong>the</strong> output generated<br />
can provide an <strong>in</strong>terest<strong>in</strong>g support<br />
for decision mak<strong>in</strong>g. Such models already<br />
exist, <strong>in</strong>clud<strong>in</strong>g a model<strong>in</strong>g system<br />
called Cage <strong>Aquaculture</strong> Decision<br />
Support Tool and ano<strong>the</strong>r called<br />
Modell<strong>in</strong>g-Ongrow<strong>in</strong>g fish farms<br />
Monitor<strong>in</strong>g, which uses multi-criteria<br />
analysis tools to create a decision support<br />
system not only for site assessment<br />
and environmental monitor<strong>in</strong>g<br />
but also for stock<strong>in</strong>g density and economic<br />
feasibility as well (Ervik et al.,<br />
1997; Halide et al., 2009; Hansen<br />
et al., 2001; Kiefer. et al., 2008; Rensel<br />
et al., 2006; Stigebrandt et al., 2004).<br />
We present <strong>in</strong> Table 1 a list of criteria<br />
that have been widely used <strong>in</strong> several<br />
of our site assessment studies. Each<br />
criterion should be studied and given<br />
a “grade” (i.e., 1 to 10) accord<strong>in</strong>g to<br />
its suitability and importance. Fur<strong>the</strong>rmore,<br />
each criteria should be<br />
given a “weight” (say, from 1 to 3),<br />
correspond<strong>in</strong>g to its <strong>in</strong>dividual importance<br />
<strong>in</strong> <strong>the</strong> process—which vary <strong>in</strong><br />
different projects <strong>in</strong> different regions.<br />
The “grade” of each criterion should<br />
<strong>the</strong>n be multiplied by its “weight,”<br />
generat<strong>in</strong>g values that should be added<br />
to one ano<strong>the</strong>r result<strong>in</strong>g <strong>in</strong> an overall<br />
grade for <strong>the</strong> site. This has proven to<br />
be a practical and reliable tool <strong>in</strong> determ<strong>in</strong><strong>in</strong>g<br />
<strong>the</strong> suitability of sites for open<br />
ocean aquaculture ventures.<br />
A proper understand<strong>in</strong>g of project<br />
requirements will provide <strong>the</strong> knowledge<br />
to establish <strong>the</strong> <strong>in</strong>puts and respective<br />
weights to create a unique<br />
hypo<strong>the</strong>tical model. In general, experience<br />
shows that most potential areas<br />
May/June 2010 Volume 44 Number 3 23
FIGURE 1<br />
Case study location. (A) Aerial photo of Culebra Island, Puerto Rico, show<strong>in</strong>g <strong>the</strong> cage site (“X”). (B) Vic<strong>in</strong>ity map show<strong>in</strong>g <strong>the</strong> cage site coord<strong>in</strong>ates<br />
(black square).<br />
24 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal
TABLE 1<br />
Site selection criteria.<br />
Site Assessment Criteria for Open Ocean Cage <strong>Aquaculture</strong><br />
Feasibility Study/Site Assessment<br />
Checklist<br />
Yes No In Progress Notes<br />
GIS, Google Earth, satellite images<br />
Maps, hydrographic/navigational charts<br />
Areas of conflict<strong>in</strong>g use (identify/elim<strong>in</strong>ate)<br />
Tentative site selected<br />
Legal framework (local, state, country)<br />
Acceptance of project by local government/public<br />
Manpower available at all levels<br />
Subcontractors for key services (net clean<strong>in</strong>g, div<strong>in</strong>g)<br />
Security<br />
Accessibility—roads, dock, enterta<strong>in</strong>ment, etc.<br />
Land-based facilities (comfortable hous<strong>in</strong>g for staff)<br />
Communications (phone, computers, etc.)<br />
Electricity<br />
Freshwater<br />
Proximity to process<strong>in</strong>g plant, airport, port<br />
Environmental basel<strong>in</strong>e/assessment/monitor<strong>in</strong>g<br />
Bioremediation, mitigation needs<br />
Depth profile; bathymetry (desirable 30–60 m)<br />
Distance from shore (desirable 1–6 km)<br />
Bottom type (desirable sandy)<br />
Exposure to w<strong>in</strong>d; fetch<br />
Currents velocity (desirable 0.2–1.5 knots)<br />
Maximum wave height (swell) (>3 m)<br />
Tides (related to coastal-driven tidal currents)<br />
Water quality <strong>in</strong> general (samples/analyze)<br />
River runoff/stratification layers (seasonal)<br />
Plankton occurrence and distribution<br />
Red tides, plankton blooms<br />
Predators—sharks, birds, seals, etc.<br />
Potential for expansion—available adjacent area<br />
Technological and economical feasibility<br />
Understand commitment, <strong>in</strong>vestment, time required<br />
F<strong>in</strong>al site selected:<br />
cont<strong>in</strong>ued<br />
May/June 2010 Volume 44 Number 3 25
TABLE 1<br />
Cont<strong>in</strong>ued<br />
Case study<br />
Description of site selected for open ocean aquaculture us<strong>in</strong>g <strong>the</strong> criteria previously described. (Snapperfarm, Inc., Puerto Rico).<br />
Site Coord<strong>in</strong>ates:<br />
Nor<strong>the</strong>rn Boundary: 18° 16.67N<br />
Sou<strong>the</strong>rn Boundary: 18° 16.4N<br />
Eastern Boundary: 65° 19.72W<br />
Western Boundary: 65° 20W<br />
Site area: 500 × 500 m = 250,000 m 2<br />
Characteristics: Oceanic<br />
Temperature: 25°C–32°C<br />
Sal<strong>in</strong>ity: 32–36 ppt<br />
Dissolved oxygen: 6–7 mg/L<br />
Currents: 0.25–1.5 knots<br />
Current direction: NW to SE, tidal driven, NW net transport<br />
Tidal variation: 0.3 m<br />
Depth: 28 m<br />
Fetch<br />
North: 1.6 km (Luis Peña Island)<br />
South: 14.5 km (Vieques Island)<br />
East: 3.2 km (Culebra Island)<br />
West: 27 km (Puerto Rico)<br />
<strong>in</strong>itially identified turn out not to be<br />
suitable because of some unforeseen<br />
issues related to some of <strong>the</strong> selection<br />
criteria described below.<br />
Infrastructure<br />
When evaluat<strong>in</strong>g a site, <strong>the</strong> first and<br />
foremost aspects to consider are <strong>in</strong>frastructure<br />
support and logistics. A site<br />
may meet all of <strong>the</strong> o<strong>the</strong>r criteria, but<br />
if it is <strong>in</strong>accessible and completely cutoff<br />
from a major city, <strong>the</strong> rest of <strong>the</strong><br />
world, and all <strong>the</strong> elements required<br />
for <strong>the</strong> operation, a number of problems<br />
will arise.<br />
Although several remote salmon<br />
farms<strong>in</strong>Sou<strong>the</strong>rnChileareentirely<br />
based on barges and served by boats,<br />
26 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
it is assumed that any open ocean<br />
aquaculture operation will need a<br />
land-based facility nearby. Thus, an<br />
important factor is accessibility. How<br />
close is <strong>the</strong> land site to ma<strong>in</strong> roads,<br />
three phase power l<strong>in</strong>es, public transportation,<br />
ports, dock<strong>in</strong>g facilities, airport,<br />
and air cargo freight? Both people<br />
and shipments should be able to come<br />
and go relatively easily. The communications<br />
<strong>in</strong>frastructure is also extremely<br />
important. Does <strong>the</strong> area have an<br />
acceptable satellite and telecommunications<br />
<strong>in</strong>frastructure? This will determ<strong>in</strong>e<br />
how well telephones, faxes,<br />
computers, mobile phones, and e-mail<br />
will operate. Without <strong>the</strong>se basics,<br />
both <strong>the</strong> staff and <strong>the</strong> bus<strong>in</strong>ess itself<br />
will suffer. There should also be reliable<br />
access to postal services like mail,<br />
FedEx, DHL, and UPS.<br />
Ano<strong>the</strong>r important item is <strong>the</strong><br />
availability and costs of electricity and<br />
fuel. The ideal scenario <strong>in</strong>cludes a reliable<br />
and affordable energy supply and<br />
does not require fuel to be transported<br />
over large distances. F<strong>in</strong>ally, <strong>the</strong> availability<br />
and quality of freshwater should<br />
be considered. The importance of this<br />
cannot be overstated. Good quality<br />
freshwater must be readily available<br />
from public services for <strong>the</strong> landbased<br />
support<strong>in</strong>g facility. Potable<br />
water can also be obta<strong>in</strong>ed from wells<br />
ortrucked<strong>in</strong>,andbothalternatives<br />
should be analyzed.
Services and Materials<br />
The items <strong>in</strong> this section are partially<br />
related to <strong>in</strong>frastructure as well<br />
because <strong>the</strong>y deal with accessibility to<br />
elements that are crucial for any aquaculture<br />
operation. First, what is <strong>the</strong><br />
site’s proximity to a city? This <strong>in</strong>volves<br />
access to th<strong>in</strong>gs like hous<strong>in</strong>g, schools,<br />
hospitals, police, enterta<strong>in</strong>ment, cultural<br />
resources, sports, and so forth.<br />
Also, what is <strong>the</strong> proximity to shopp<strong>in</strong>g<br />
and markets? This is important<br />
because a supply of ice, food, clean<strong>in</strong>g<br />
materials, and utensils will always be<br />
required and staff will need a break<br />
form <strong>the</strong> work of <strong>the</strong> farm. Next, <strong>the</strong><br />
access to construction materials such<br />
as lumber, concrete, steel, fiberglass,<br />
polyv<strong>in</strong>yl chloride pipes, and tools<br />
should be studied along with <strong>the</strong> availability<br />
of qualified mechanical, electrical,<br />
plumb<strong>in</strong>g, well drill<strong>in</strong>g, and<br />
general contractor expertise.<br />
Manpower/Personnel<br />
It is extremely important to evaluate<br />
<strong>the</strong> workforce situation. Where are<br />
<strong>the</strong>peoplewhoarego<strong>in</strong>gtorun<strong>the</strong><br />
operation? What is <strong>the</strong> availability of<br />
skilled and unskilled labor at all levels<br />
(laborers, technicians, divers) <strong>in</strong> <strong>the</strong> region?<br />
What is <strong>the</strong> availability of adm<strong>in</strong>istrative<br />
and technical staff (managers,<br />
biologists, hatchery managers)? It is<br />
wellknownthat<strong>in</strong>aquaculture,as<br />
with any o<strong>the</strong>r production activity,<br />
<strong>the</strong> success of <strong>the</strong> operation depends<br />
on <strong>the</strong> qualifications of those who<br />
will run it. This should be analyzed<br />
closely because any number of arrangements<br />
to fill essential jobs are possible.<br />
A careful study will <strong>in</strong>volve divid<strong>in</strong>g<br />
available manpower <strong>in</strong>to local/state/<br />
national/<strong>in</strong>ternational personnel and<br />
determ<strong>in</strong><strong>in</strong>g availability and constra<strong>in</strong>ts<br />
before decid<strong>in</strong>g on <strong>the</strong> best scenario.<br />
It is likely that at least a few<br />
workers with certa<strong>in</strong> levels of expertise<br />
will have to be brought up from o<strong>the</strong>r<br />
regions or even from abroad.<br />
Legal Framework<br />
Access to ocean locations to place<br />
cages for offshore aquaculture <strong>in</strong><br />
most countries <strong>in</strong>volves <strong>the</strong> application<br />
of a mar<strong>in</strong>e concession permit from<br />
<strong>the</strong> government. Notably, <strong>the</strong> United<br />
States does not currently have a permitt<strong>in</strong>g<br />
and leas<strong>in</strong>g process for <strong>the</strong><br />
EEZ, although Congress is consider<strong>in</strong>g<br />
<strong>the</strong> issue. A mar<strong>in</strong>e concession permit<br />
provides <strong>the</strong> applicant with <strong>the</strong><br />
legal right for <strong>the</strong> use of public doma<strong>in</strong><br />
property or resources for private purposes.<br />
Usually, <strong>the</strong> government agency<br />
or agencies responsible with manag<strong>in</strong>g<br />
this process require a yearly usage fee<br />
(rent) for <strong>the</strong> concession. Depend<strong>in</strong>g<br />
on <strong>the</strong> country, this fee can be waived<br />
for <strong>the</strong> <strong>in</strong>itial years <strong>in</strong> which <strong>the</strong> project<br />
is be<strong>in</strong>g started until <strong>the</strong> company beg<strong>in</strong>s<br />
report<strong>in</strong>g a positive cash flow. As<br />
part of <strong>the</strong> concession application process,<br />
an environmental assessment or<br />
an environmental impact statement<br />
may be required, and it usually <strong>in</strong>volves<br />
hir<strong>in</strong>g a local consult<strong>in</strong>g firm<br />
registered or certified as competent<br />
with <strong>the</strong> appropriate government<br />
agency to perform <strong>the</strong> environmental<br />
assessment or environmental impact<br />
statement document. The application<br />
is usually reviewed by all <strong>the</strong> government<br />
agencies required by <strong>the</strong><br />
country’s law to do so, which varies<br />
between countries. Applications can<br />
take between 8 months and as long<br />
as 5 years to process, depend<strong>in</strong>g on<br />
<strong>the</strong> country’s permit process bureaucracy.<br />
Shore side property on which<br />
to base a support facility for <strong>the</strong> offshore<br />
cage site usually is also required.<br />
The issue of coastal land ownership<br />
(private, communities, government<br />
easement, etc.) <strong>in</strong> that specific area<br />
should be carefully evaluated. Is <strong>the</strong><br />
site itself up to date and <strong>in</strong> accordance<br />
with all local regulations, permits, and<br />
laws? If not, how easily can this be<br />
addressed?<br />
It is important to become familiar<br />
with <strong>the</strong> local, state, and country government<br />
regulations because both <strong>the</strong><br />
land and <strong>the</strong> ocean sites will deal<br />
with a particular set of regulations<br />
and laws. These of course are different<br />
from country to country. It is also important<br />
to carefully look <strong>in</strong>to all local<br />
labor laws and regulations. Moreover,<br />
it is important to check <strong>the</strong> availability<br />
of lawyers, attorneys, and facilitators to<br />
consult on <strong>the</strong>se previously mentioned<br />
items and any o<strong>the</strong>rs that will <strong>in</strong>evitably<br />
arise. The best solution is to always<br />
hire a local lawyer or a consult<strong>in</strong>g company<br />
that is registered to provide <strong>the</strong><br />
documents and expertise and has access<br />
to government officials, regulators,<br />
and permit grantees.<br />
The tim<strong>in</strong>g of permit application<br />
also needs to be considered. Submitt<strong>in</strong>g<br />
an application between a national<br />
election cycle can delay <strong>the</strong> evaluation<br />
of <strong>the</strong> permit substantially. In some<br />
countries, national election laws limit<br />
<strong>the</strong> ability of permitt<strong>in</strong>g agencies to<br />
make decisions for 6 months before<br />
or after an election cycle. In addition,<br />
<strong>the</strong> shift of agency political appo<strong>in</strong>tees<br />
can take longer, h<strong>in</strong>der<strong>in</strong>g <strong>the</strong> approval<br />
of permits. Local, regional, and/or national<br />
government support and political<br />
connections are crucial. Submitt<strong>in</strong>g<br />
applications <strong>in</strong> synchrony with <strong>the</strong><br />
election cycle may be carefully considered<br />
as <strong>the</strong>y can ei<strong>the</strong>r help expedite or<br />
curb permit approval.<br />
Social and Economic Factors<br />
Local social and economic factors<br />
will have a great impact on <strong>the</strong> successful<br />
long-term execution of a project.<br />
The benefits and impact of generat<strong>in</strong>g<br />
employment <strong>in</strong> <strong>the</strong> area should<br />
May/June 2010 Volume 44 Number 3 27
e understood <strong>in</strong> advance. Some o<strong>the</strong>r<br />
elements of which to be aware <strong>in</strong>clude<br />
public and government acceptance/<br />
perception of <strong>the</strong> project, exist<strong>in</strong>g<br />
and potential tourism <strong>in</strong> <strong>the</strong> area, and<br />
population demographics, such as<br />
standard of liv<strong>in</strong>g and <strong>in</strong>come levels<br />
of people. Also, it is important to<br />
know if <strong>the</strong>re are <strong>the</strong>re any compet<strong>in</strong>g<br />
activities <strong>in</strong> or near <strong>the</strong> offshore site,<br />
such as fish<strong>in</strong>g, whale watch<strong>in</strong>g, freight<br />
vessel transit, or oil exploration, which<br />
could negatively impact your project.<br />
Ano<strong>the</strong>r important socioeconomic<br />
factor that could negatively impact<br />
any operation is site security. A careful<br />
evaluation of risks regard<strong>in</strong>g piracy,<br />
<strong>the</strong>ft, and vandalism is imperative.<br />
Any open ocean or coastal aquaculture<br />
operation will have to count on<br />
<strong>the</strong> approval and support of local communities<br />
of fishermen (if any) and fishermen<br />
organizations such as associations,<br />
colonies, community centers, and so<br />
forth. To this effect, operators must ensure<br />
that <strong>the</strong> farm will br<strong>in</strong>g social and<br />
economic advantages to <strong>the</strong> region by<br />
employ<strong>in</strong>g directly and <strong>in</strong>directly a<br />
number of local <strong>in</strong>dividuals and generat<strong>in</strong>g<br />
benefits one way or ano<strong>the</strong>r. Some<br />
countries will exempt <strong>the</strong> company<br />
from mar<strong>in</strong>e concession lease fees if<br />
an agreed number of local jobs are generated.<br />
Aga<strong>in</strong>, public perceptions are<br />
pervasive and quite often more important<br />
than <strong>the</strong> reality, and project operators<br />
will have to deal with <strong>the</strong>m on a<br />
daily basis. Hav<strong>in</strong>g a local community<br />
endorsement for establishment of <strong>the</strong><br />
project helps <strong>the</strong> government agencies<br />
<strong>in</strong> decid<strong>in</strong>g to favor <strong>the</strong> grant<strong>in</strong>g of <strong>the</strong><br />
permit because politically it is difficult<br />
tonotgrantapermitthatmeetsall<br />
o<strong>the</strong>r requirements established by law.<br />
Hydrography<br />
Assum<strong>in</strong>g that <strong>the</strong> open ocean operation<br />
will rely on a land-based facility<br />
28 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
for its hatchery supply of f<strong>in</strong>gerl<strong>in</strong>gs<br />
and nursery, specific sitesurveyswillbe<br />
required for both land-based and open<br />
ocean grow-out facilities. Figure 2<br />
illustrates materials, methods, and<br />
<strong>in</strong>strumentation used for collect<strong>in</strong>g<br />
basic data required for site assessment<br />
studies. It is important to understand,<br />
to <strong>the</strong> maximum extent possible, factors<br />
perta<strong>in</strong><strong>in</strong>g to <strong>the</strong> region’s hydrography<br />
and oceanography. Among <strong>the</strong><br />
most important factors that need to<br />
be taken <strong>in</strong>to consideration at both<br />
<strong>the</strong> land and ocean sites are water<br />
source (quality and quantity), seasonal<br />
variations <strong>in</strong> water quality parameters<br />
such as temperature, dissolved oxygen,<br />
FIGURE 2<br />
sal<strong>in</strong>ity, and turbidity, and tidal ranges<br />
under both normal and storm conditions.<br />
For <strong>the</strong> offshore site, current patterns<br />
onshore, offshore, upstream, and<br />
downstream are very important, as are<br />
depth profiles for <strong>the</strong> area. For <strong>the</strong> land<br />
site, <strong>the</strong> seasonal flood levels and <strong>the</strong><br />
potential danger of flood<strong>in</strong>g dur<strong>in</strong>g annual<br />
ra<strong>in</strong>y season are very important<br />
as well as <strong>the</strong> water <strong>in</strong>take situation<br />
(height/distance between <strong>in</strong>take and<br />
pumps, hydraulic head, etc.).<br />
Water temperature and its correlation<br />
with fish growth is a major profit<br />
driver to commercial farm<strong>in</strong>g (Benetti<br />
et al., 2010; Person-Le Ruyet et al.,<br />
2004). And depth profile and currents<br />
Site assessment for open ocean aquaculture requires a wide range of studies us<strong>in</strong>g a variety of<br />
both simple and sophisticated <strong>in</strong>strumentation. The pictures show some of <strong>the</strong> materials and<br />
methods used dur<strong>in</strong>g a site selection study conducted for an open ocean operation off <strong>the</strong> coast<br />
of Culebra Island, Puerto Rico. (A and A.1) Current surface velocity was measured with a simple<br />
drifter or drogue. (B) The towable underwater video camera permits <strong>in</strong>spection of benthic communities.<br />
The video images are recorded to a portable recorder. (C) A digital fathometer with a<br />
paper recorder was used to determ<strong>in</strong>e site depth. (D) All survey positions were recorded with a<br />
12-channel Global Position System with differential corrections and stored to <strong>in</strong>strument memory<br />
(photos by Brian O’Hanlon, Snapperfarm, Inc.).
patterns are considered limit<strong>in</strong>g physical<br />
factors; all must receive high<br />
weights <strong>in</strong> determ<strong>in</strong><strong>in</strong>g hypo<strong>the</strong>tical<br />
site models. Current velocity is likely<br />
<strong>the</strong> most important factor for both <strong>the</strong><br />
carry<strong>in</strong>g capacity of <strong>the</strong> farm and <strong>the</strong><br />
management of adverse water quality<br />
and benthic impacts and must be thoroughly<br />
studied. As most open ocean<br />
aquaculture farms currently operat<strong>in</strong>g<br />
throughout <strong>the</strong> world are located with<strong>in</strong><br />
only a few miles from shore, tidal<br />
currents often play major roles <strong>in</strong> determ<strong>in</strong><strong>in</strong>g<br />
current patterns (velocities<br />
and directions). Indeed, with<strong>in</strong> authors’<br />
experiences, <strong>the</strong> current velocities<br />
<strong>in</strong> <strong>the</strong>se successful open ocean<br />
farms range from 0.2 to 1.5 knots—<br />
with slacks and change <strong>in</strong> directions <strong>in</strong>variably<br />
observed <strong>in</strong> synchrony with<br />
<strong>the</strong> tidal variations. Examples of current<br />
meters commonly used for measur<strong>in</strong>g<br />
current velocities and directions are<br />
shown <strong>in</strong> Figures 2, 3, 4, and 5.<br />
FIGURE 3<br />
Water column current velocity and direction<br />
measurement <strong>in</strong>struments. (A) RDI Sent<strong>in</strong>el<br />
acoustic Doppler current profiler (ADCP)<br />
sends four acoustic rays from ocean bottom<br />
to surface. Instrument measures Doppler shift<br />
<strong>in</strong> frequency reflected back from sediment or<br />
o<strong>the</strong>r particles <strong>in</strong> water column at programmed<br />
distance <strong>in</strong>tervals until surface is reached.<br />
(B) Depiction of moor<strong>in</strong>g buoy for a s<strong>in</strong>gle<br />
po<strong>in</strong>t current velocity and direction measurements.<br />
(C) RDI Sent<strong>in</strong>el ADCP mounted on<br />
frame at ocean bottom. (D) InterOcean S4<br />
current meter, which also measures at a s<strong>in</strong>gle<br />
po<strong>in</strong>t us<strong>in</strong>g <strong>the</strong> Doppler shift pr<strong>in</strong>ciple.<br />
FIGURE 4<br />
Example of typical data sets obta<strong>in</strong>ed from current studies <strong>in</strong> site surveys for open ocean aquaculture.<br />
(A) An InterOcean S4 s<strong>in</strong>gle po<strong>in</strong>t current meter data for speed <strong>in</strong> centimeters per second,<br />
direction <strong>in</strong> degrees, and water depth <strong>in</strong> meters. (B) Current rose. (Data from South Eleu<strong>the</strong>ra,<br />
Bahamas. Courtesy of Aquasense, LLC, <strong>the</strong> Cape Eleu<strong>the</strong>ra Research Institute and Ocean Spar,<br />
LLC.) (C) RDI ADCP current mean speed profile for seven days sampled every 20 m<strong>in</strong>.<br />
Topography/Geology<br />
Important elements of <strong>the</strong> land site<br />
are <strong>the</strong> availability of land, <strong>in</strong>clud<strong>in</strong>g<br />
possibility for expansion through government<br />
or private ownership, elevation<br />
of land and its contours, which<br />
should be a m<strong>in</strong>imum of 2–3 m<br />
above high tide, dra<strong>in</strong>age, and soil texture<br />
and composition (construction<br />
and/or compactibility to hold water—<br />
sandy, clay, silt, etc.). These criteria<br />
are related to construction of <strong>the</strong> landbased<br />
facility needed to support <strong>the</strong><br />
open ocean grow-out cage operation.<br />
May/June 2010 Volume 44 Number 3 29
FIGURE 5<br />
An RDI Sent<strong>in</strong>el ADCP depict<strong>in</strong>g <strong>the</strong> four acoustic cones that collect <strong>the</strong> current speed and direction through <strong>the</strong> water column. The graph image<br />
projected represents <strong>the</strong> results of <strong>the</strong> read<strong>in</strong>gs (image courtesy of Johnny Chavarria Viteri).<br />
Treece (2000) provided a thorough review<br />
on site selection criteria for landbased<br />
aquaculture facilities.<br />
Climate/Meteorology<br />
Seasonal variations of meteorological<br />
parameters will greatly impact any<br />
project. O<strong>the</strong>r factors are prevail<strong>in</strong>g<br />
w<strong>in</strong>d velocity and direction; average,<br />
maximum, and m<strong>in</strong>imum air temperatures;<br />
average, maximum, and m<strong>in</strong>imum<br />
ra<strong>in</strong>fall; local waves, storms,<br />
tsunamis, earthquakes, typhoons, and<br />
hurricane history and frequency; and<br />
solar radiation and evaporation rates.<br />
Too much ra<strong>in</strong> associated with <strong>the</strong><br />
presence of mounta<strong>in</strong>s and rivers will<br />
likely create extensive runoffs will<br />
cause lower sal<strong>in</strong>ities, heavy loads of<br />
suspended solids, and nutrients that<br />
may reach large areas compris<strong>in</strong>g tens<br />
of kilometers of coast waters. These<br />
runoffs are known to affect <strong>the</strong> health<br />
of <strong>the</strong> fish be<strong>in</strong>g raised, especially pelagic<br />
species.<br />
30 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
These are obvious but often overlooked<br />
parameters. Even recently,<br />
several cage farm operations were<br />
developed <strong>in</strong> hurricane-prone areas<br />
us<strong>in</strong>g traditional float<strong>in</strong>g, gravity<br />
cages. The risks of <strong>the</strong>se farms be<strong>in</strong>g<br />
hit by a hurricane were too high, and<br />
with<strong>in</strong> <strong>the</strong> few years that <strong>the</strong>y have<br />
been operat<strong>in</strong>g, some have lost <strong>the</strong>ir<br />
entire <strong>in</strong>frastructure and stock with<br />
enormous f<strong>in</strong>ancial losses.<br />
For hurricane- or storm-prone<br />
areas such as <strong>the</strong> Caribbean Sea, for<br />
example, it is advisable to deploy advanced<br />
cage systems that can be deployed<br />
and operated submerged or<br />
semisubmerged (e.g., SeaStation by<br />
Ocean Spar, Aquapod by Ocean<br />
Farm Technologies, OceanGlobe by<br />
BYKS AS, Ocean Drifter (a concept<br />
design by Cliff Goudey), Tension<br />
Leg Cage by Refamed, Hoverflex by<br />
Subflex,etc).Figures6A,6B,7A,<br />
and 7B depict SeaStation and Aquapod<br />
submergible cages commonly used for<br />
FIGURE 6<br />
Ocean Spar, LLC Sea Station 6,400 m 3 cages<br />
deployed off <strong>the</strong> Caribbean Coast of Panama<br />
(photos courtesy of Open Blue Sea Farms<br />
LLC). These cages are submergible and are<br />
only raised to <strong>the</strong> surface for clean<strong>in</strong>g, servic<strong>in</strong>g<br />
and harvest<strong>in</strong>g.
FIGURE 7<br />
Aquapods Net Pens (3,000 m 3 ) cages deployed<br />
off <strong>the</strong> Coast of Culebra Island, Puerto Rico.<br />
These cages are also submergible and only<br />
brought to <strong>the</strong> surface for clean<strong>in</strong>g, servic<strong>in</strong>g,<br />
and harvest<strong>in</strong>g (photos courtesy of Snapperfarm,<br />
Inc. and OceanFarm Technologies).<br />
open ocean aquaculture <strong>the</strong> world<br />
over.<br />
Pollution<br />
Organic and <strong>in</strong>organic pollution<br />
sources must be carefully analyzed before<br />
complet<strong>in</strong>g <strong>the</strong> land and ocean site<br />
surveys. It is important to study and<br />
understand past, present, and future<br />
sources of both organic and <strong>in</strong>organic<br />
pollution; oil, untreated sewage, bacteria,<br />
and o<strong>the</strong>r pathogens present <strong>in</strong><br />
municipal (human) waste discharges;<br />
heavy metals and chlor<strong>in</strong>ated hydrocarbons<br />
present <strong>in</strong> <strong>in</strong>dustrial waste<br />
discharges; pesticides and fertilizers<br />
present <strong>in</strong> agricultural waste discharges;<br />
and organic and <strong>in</strong>organic<br />
aquaculture waste discharges such as<br />
ammonia, chlor<strong>in</strong>e, antibiotics, and<br />
drugs. For example, <strong>in</strong>stall<strong>in</strong>g a landbased<br />
facility to support <strong>the</strong> offshore<br />
farm at any location receiv<strong>in</strong>g nearby<br />
effluent water from a large agriculture<br />
operation rely<strong>in</strong>g heavily on pesticides<br />
must be avoided. Oil pollution is ano<strong>the</strong>r<br />
major risk. A case <strong>in</strong> po<strong>in</strong>t is<br />
<strong>the</strong> 2010 Deepwater Horizon/BP oil<br />
spill <strong>in</strong> <strong>the</strong> Gulf of Mexico (GOM).<br />
On <strong>the</strong> basis of current satellite imagery<br />
taken around <strong>the</strong> GOM region<br />
(http://www.cstars.miami.edu), it can<br />
be presumed that had offshore cages<br />
been located <strong>in</strong> <strong>the</strong> areas, which are<br />
now covered with oil, significant loss<br />
of crops and <strong>in</strong>frastructure would have<br />
occurred because of <strong>the</strong> contam<strong>in</strong>ation<br />
and mortality caused by <strong>the</strong> crude oil.<br />
There would also have been a risk of<br />
contam<strong>in</strong>ation and mortality caused<br />
by <strong>the</strong> use of chemical dispersants at<br />
<strong>the</strong> source of <strong>the</strong> oil spill (Kev<strong>in</strong> Polk,<br />
personal communication, May 2010).<br />
Biology<br />
Although biological risks such as<br />
harmful algal blooms (particularly red<br />
tides) are generally associated with<br />
eutrophic environments <strong>in</strong> shallower<br />
areas, <strong>the</strong>ir historical occurrence <strong>in</strong><br />
<strong>the</strong> area must be studied for risk assessment.<br />
Heavy mortalities can arise from<br />
harmful algal blooms or red tides<br />
(Anderson et al., 2001). It is also important<br />
to identify and avoid areas<br />
where large numbers of predators<br />
such as sharks, seals, and o<strong>the</strong>r large<br />
mar<strong>in</strong>e mammals are known to<br />
occur. This is often unpractical, but<br />
one must beware that <strong>the</strong> presence of<br />
predators can <strong>in</strong>cur high costs from<br />
damaged nets and escape of stock and<br />
<strong>the</strong> need for predator avoidance technologies.<br />
Escapes because of shark attacks<br />
on <strong>the</strong> nets of open ocean cages<br />
<strong>in</strong> <strong>the</strong> Caribbean have been reported<br />
to cause significant losses of crops <strong>in</strong><br />
recent years. However, problems with<br />
escapements have been brought under<br />
control upon <strong>the</strong> establishment of<br />
better management practices, such<br />
as efficient collection and removal of<br />
mortalities from cages, and cage systems<br />
with improved antipredator<br />
devices (Benetti et al., 2010). In addition,<br />
for both <strong>the</strong> open ocean site and<br />
<strong>the</strong> adjacent land-based facility, proper<br />
identification and knowledge regard<strong>in</strong>g<br />
abundance and seasonality of native<br />
phytoplankton and zooplankton<br />
organisms, such as those associated<br />
with toxic or harmful algal blooms, is<br />
crucial to counteract<strong>in</strong>g <strong>the</strong> clogg<strong>in</strong>g<br />
of filters and pipes at <strong>the</strong> hatchery<br />
and negatively affect<strong>in</strong>g <strong>the</strong> cage site<br />
(Anderson et al., 2001).<br />
Environment<br />
The importance of <strong>the</strong> environmental<br />
susta<strong>in</strong>ability of <strong>the</strong> operation<br />
and of m<strong>in</strong>imiz<strong>in</strong>g any environmental<br />
impact to local ecosystems must be<br />
emphasized. Perceptions play a role,<br />
and all efforts must be made to educate<br />
all stakeholders about <strong>the</strong> positive impacts<br />
that <strong>the</strong> operation will have <strong>in</strong> <strong>the</strong><br />
region and how potential negative<br />
impacts will be mitigated. Is <strong>the</strong> area<br />
<strong>in</strong> which your site is located already<br />
be<strong>in</strong>g utilized to its maximum extent<br />
by o<strong>the</strong>r users and uses? Compet<strong>in</strong>g<br />
uses of <strong>the</strong> environment, such as recreation,<br />
tourism, navigation, fisheries,<br />
oil and gas platforms, and o<strong>the</strong>rs,<br />
must be taken <strong>in</strong>to careful consideration.<br />
It is advisable to avoid close<br />
proximity to mar<strong>in</strong>e protected areas<br />
(reservations, parks, etc.) or environmentally<br />
sensitive coastal areas such<br />
as mangroves. Known areas of migration<br />
of sea turtles and mar<strong>in</strong>e mammals<br />
should be avoided to m<strong>in</strong>imize<br />
conflicts with conservation agencies<br />
and nongovernmental organizations.<br />
With land-based facilities required<br />
for support<strong>in</strong>g open ocean cage culture<br />
operations, <strong>the</strong> <strong>in</strong>frastructure should<br />
be <strong>in</strong> place or conditions should be<br />
May/June 2010 Volume 44 Number 3 31
such that a suitable system can be built.<br />
The facility should <strong>in</strong>clude systems to<br />
control discharge water (waste water<br />
disposal systems) and m<strong>in</strong>imize environmental<br />
impact. This can be accomplished<br />
by us<strong>in</strong>g sedimentation ponds,<br />
filters, <strong>in</strong>jection wells, buffer areas,<br />
etc.). A study <strong>in</strong>to local regulations regard<strong>in</strong>g<br />
mitigation/treatment of wastewater<br />
before discharg<strong>in</strong>g should be<br />
carried out prior f<strong>in</strong>aliz<strong>in</strong>g site selection.<br />
Because of biosecurity and<br />
environmental concerns related to effluent<br />
discharges, <strong>the</strong>re is a trend toward<br />
us<strong>in</strong>g recirculat<strong>in</strong>g aquaculture<br />
systems <strong>in</strong> land-based facilities, <strong>in</strong>clud<strong>in</strong>g<br />
mar<strong>in</strong>e fish hatcheries and<br />
nurseries. This option should be considered,<br />
especially <strong>in</strong> areas where <strong>the</strong><br />
water supply is of questionable quality<br />
and/or effluent discharges from <strong>the</strong><br />
facilities may represent a logistic or a<br />
legal/permitt<strong>in</strong>g problem.<br />
Because of high capital <strong>in</strong>vestment<br />
and operational costs required, offshore<br />
aquaculture can be profitable<br />
only if <strong>the</strong> farm can take advantage<br />
of economies of scale (Benetti et al.,<br />
2006). The carry<strong>in</strong>g capacity of <strong>the</strong> environment<br />
and <strong>the</strong> suitability to implement<br />
a large-scale farm for economies<br />
of scale are directly correlated. The<br />
waste products generated by metabolic<br />
processes and uneaten food are directly<br />
proportional to scale of <strong>the</strong> farm<strong>in</strong>g activity,<br />
and <strong>the</strong> accumulation of organic<br />
matter beneath <strong>the</strong> cages and <strong>in</strong> surround<strong>in</strong>g<br />
environment could drastically<br />
alter <strong>the</strong> seafloor fauna and flora<br />
(Beveridge, 2004; Bridger and Costa-<br />
Pierce, 2003; Gowen, 1991; Iwama,<br />
1991; Karakassis et al., 1998; Pearson<br />
and Black, 2001; Wu, 1995). This has<br />
<strong>the</strong> potential to cause negative environmental<br />
impacts and consequently<br />
compromise <strong>the</strong> economic viability of<br />
<strong>the</strong> project. Such adverse environmental<br />
consequences can be <strong>in</strong>creased with<br />
32 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
poor quality food and feed utilization<br />
(Huiwen and Y<strong>in</strong>glan, 2007). These<br />
negative conditions are generally associated<br />
with <strong>in</strong>shore situations and comparatively<br />
shallow or weak currents <strong>in</strong><br />
protected coastal areas (Goldburg<br />
et al., 1996). Offshore and open<br />
ocean sites with greater depth and<br />
stronger currents considerably reduce<br />
<strong>the</strong> effect of waste accumulation by allow<strong>in</strong>g<br />
an efficient dispersion of pen<br />
effluent and its assimilation by <strong>the</strong><br />
surround<strong>in</strong>g environment (Benetti<br />
et al., 2008, 2010; Colbourne, 2005;<br />
Hansen et al., 2001; Pérez et al.,<br />
2003; Stigebrandt et al., 2004).<br />
A basic model to estimate <strong>the</strong> spatial<br />
scale of nutrient dispersion on <strong>the</strong><br />
basis of organic material (uneaten food<br />
and feces) settl<strong>in</strong>g velocity (v), water<br />
depth (d ), and current velocity (V ),<br />
uses <strong>the</strong> follow<strong>in</strong>g equation D = dV/v,<br />
where D represents <strong>the</strong> horizontal distance<br />
of waste dispersion (Gowen and<br />
Bradbury,1987).Thismodelshows<br />
<strong>the</strong> paramount importance of highenergy<br />
conditions associated with<br />
open ocean environments to overcome<br />
<strong>the</strong>se problems.<br />
Besides <strong>the</strong> impacts on <strong>the</strong> benthos<br />
underneath offshore farms and surround<strong>in</strong>g<br />
area, fish meal and oil utilization<br />
for aquafeeds (Jackson, 2009;<br />
Schipp, 2008), transfer of diseases and<br />
antibiotics to environment (Smith<br />
and Samuelsen, 1996), and genetic<br />
impact on wild stocks due to escapes<br />
(Triantafyllidis et al., 2007) have<br />
raised most of <strong>the</strong> concerns with mar<strong>in</strong>e<br />
f<strong>in</strong>fish aquaculture offshore.<br />
Small losses (10,000 <strong>in</strong>dividuals)<br />
are attributed to storms<br />
(Dempster et al., 2002) or to predators<br />
damag<strong>in</strong>g nets (Benetti et al., 2008,<br />
2010). Thus, <strong>the</strong> use of suitable cages<br />
built for specific site requirements and<br />
best management practices to ma<strong>in</strong>ta<strong>in</strong><br />
optimal conditions are crucial to<br />
avoid escapes.<br />
Lessons to be Learned<br />
From <strong>the</strong> Recent Oil Spill<br />
<strong>in</strong> <strong>the</strong> GOM<br />
Certa<strong>in</strong> regions <strong>in</strong> oil-produc<strong>in</strong>g<br />
countries present risks associated with<br />
both wea<strong>the</strong>r and environmental disasters.<br />
For example, aside from <strong>the</strong> everpresent<br />
hurricanes and red tides, threats<br />
<strong>in</strong> <strong>the</strong> Caribbean and recently <strong>in</strong> <strong>the</strong><br />
GOM, with <strong>the</strong> BP Deepwater Horizon<br />
oil rig s<strong>in</strong>k<strong>in</strong>g and oil spill, provide an<br />
example of <strong>the</strong> greater risks and conflicts<br />
that <strong>the</strong>se large-scale disasters<br />
present to offshore aquaculture development.<br />
In <strong>the</strong>se cases, <strong>the</strong>re are obvious<br />
advantages <strong>in</strong> deploy<strong>in</strong>g submerged<br />
cages that can be ma<strong>in</strong>ta<strong>in</strong>ed and safely<br />
operated under water for extended<br />
periods of time while <strong>the</strong> oil leaks or<br />
red tides may be drift<strong>in</strong>g over <strong>the</strong>m.<br />
For that action to be a management<br />
tool, studies should be conducted to<br />
precisely determ<strong>in</strong>e at what depths <strong>the</strong><br />
oil leaks, oil emulsions, and/or red tides<br />
would affect <strong>the</strong> crop and farm <strong>in</strong>frastructure.<br />
These data are essential for<br />
plann<strong>in</strong>g <strong>the</strong> cage depth of offshore<br />
deployments.<br />
In addition, summariz<strong>in</strong>g <strong>the</strong> surface<br />
currents data for <strong>the</strong> GOM by season<br />
would help po<strong>in</strong>t out which areas<br />
are more or less prone to oil spill impacts.<br />
Access<strong>in</strong>g <strong>the</strong>se data is important<br />
for plann<strong>in</strong>g and zon<strong>in</strong>g of ocean<br />
uses and select<strong>in</strong>g suitable sites <strong>in</strong> <strong>the</strong><br />
GOM and elsewhere to develop future<br />
offshore aquaculture operations.<br />
Likewise, future moor<strong>in</strong>g designs for<br />
offshore cage systems should contemplate<br />
design<strong>in</strong>g quick-release anchor<strong>in</strong>g<br />
systems so that cages can be released to<br />
<strong>the</strong> surface and towed away from<br />
harm’s way. Strategies to move and<br />
anchor cages from harm’s way should
e conceived apriorito provide options<br />
should <strong>the</strong> need arise. Ocean<br />
technology eng<strong>in</strong>eers face <strong>the</strong> challenge<br />
of address<strong>in</strong>g <strong>the</strong>se concerns by<br />
modify<strong>in</strong>g or redesign<strong>in</strong>g <strong>the</strong> cage<br />
systems currently available (e.g., Ocean<br />
Spar, Ocean Farm Technologies,<br />
Aqual<strong>in</strong>e, SubFlex, etc.). Offshore<br />
cage system operators will also have<br />
to implement quick harvest systems<br />
to br<strong>in</strong>g <strong>the</strong> fish to market before <strong>the</strong><br />
oil spill affects <strong>the</strong>m. Aga<strong>in</strong>, apriori<br />
cont<strong>in</strong>gency plann<strong>in</strong>g and employee<br />
awareness of <strong>the</strong>se harvest<strong>in</strong>g strategies<br />
can help operators harvest <strong>the</strong><br />
crop expeditiously.<br />
As previously discussed, current<br />
satellite imagery taken around <strong>the</strong><br />
area of <strong>the</strong> Deepwater Horizon oil rig<br />
spill shows that had offshore cages<br />
been located <strong>in</strong> <strong>the</strong> areas that were covered<br />
with oil, significant loss of stock<br />
and capital would have occurred because<br />
of <strong>the</strong> contam<strong>in</strong>ation and mortality<br />
caused by <strong>the</strong> crude oil and its<br />
residues. There would also have been<br />
a risk because of contam<strong>in</strong>ation and<br />
mortality caused by <strong>the</strong> use of chemical<br />
dispersants at <strong>the</strong> source of <strong>the</strong> oil<br />
spill (http://www.cstars.miami.edu).<br />
This discussion highlights <strong>the</strong> importance<br />
of select<strong>in</strong>g regions or even<br />
countries that have m<strong>in</strong>imum potential<br />
for conflict between <strong>the</strong>ir offshore<br />
energy <strong>in</strong>dustries and locat<strong>in</strong>g offshore<br />
aquaculture production. The assurance<br />
that <strong>the</strong> ocean water quality will<br />
be ma<strong>in</strong>ta<strong>in</strong>ed becomes a real asset<br />
for a company want<strong>in</strong>g to raise and<br />
sell healthy and wholesome fish <strong>in</strong> a<br />
worldwide market.<br />
Conclusions<br />
All considerations presented <strong>in</strong><br />
Table 1 and discussed here are to be<br />
applied after general site evaluation<br />
us<strong>in</strong>g GIS, available maps and hydro-<br />
graphic charts, satellite images, and<br />
prelim<strong>in</strong>ary <strong>in</strong>formation ga<strong>the</strong>red on<br />
site. Google Earth has become a most<br />
useful tool for prelim<strong>in</strong>ary work on site<br />
assessment. Although some of <strong>the</strong><br />
parameters discussed do not directly<br />
apply when assess<strong>in</strong>g an oceanic site<br />
for cage culture per se, allareworth<br />
consider<strong>in</strong>g when select<strong>in</strong>g a land site<br />
becauseasuccessfuloffshoreoperation<br />
must rely on a land-based facility<br />
for logistic support and supply of<br />
f<strong>in</strong>gerl<strong>in</strong>gs.<br />
The utilization of high-quality<br />
feeds specific for each developmental<br />
stage of <strong>the</strong> fish, best management<br />
feed<strong>in</strong>g practices to improve feed conversion,<br />
and ma<strong>the</strong>matical models to<br />
predict and monitor environmental<br />
impacts accord<strong>in</strong>g carry<strong>in</strong>g capacity<br />
should be emphasized go<strong>in</strong>g forward.<br />
Horizontal <strong>in</strong>tegration should also be<br />
considered as a viable solution to reduce<br />
negative impacts while enhanc<strong>in</strong>g<br />
production and economic efficiency<br />
(Bunt<strong>in</strong>g,2007).Fur<strong>the</strong>rmore,ona<br />
broad scale, research to improve and<br />
reduce fish meal and fish oil utilization<br />
should be conducted to <strong>in</strong>crease both<br />
<strong>the</strong> profitability of mar<strong>in</strong>e farm<strong>in</strong>g operations<br />
and <strong>the</strong> ecological susta<strong>in</strong>ability<br />
of <strong>the</strong> <strong>in</strong>dustry as a whole.<br />
It is important to recognize from<br />
<strong>the</strong> onset that public and government<br />
understand<strong>in</strong>g and acceptance of <strong>the</strong>se<br />
commercial projects is of great importance<br />
to <strong>the</strong> future of <strong>the</strong> <strong>in</strong>dustry.<br />
Likewise, <strong>in</strong>dustry must understand<br />
that a successful site survey should necessarily<br />
<strong>in</strong>clude a study of <strong>the</strong> flora and<br />
fauna present <strong>in</strong> <strong>the</strong> area, focus<strong>in</strong>g on<br />
<strong>in</strong>dicator organisms, to establish basel<strong>in</strong>e<br />
conditions. In this way, <strong>the</strong> aquaculture<br />
company, <strong>the</strong> public, and <strong>the</strong><br />
government will know if <strong>the</strong>re are negative<br />
impacts from <strong>the</strong> project operation<br />
on <strong>the</strong> abundance of benthic and<br />
water column organisms.<br />
Lastly, companies <strong>in</strong>vest a considerable<br />
amount of time and expense <strong>in</strong><br />
assess<strong>in</strong>g whe<strong>the</strong>r a land-based support<br />
site and/or an offshore ocean production<br />
site would be suitable for a commercial<br />
fish farm. Although <strong>the</strong>se costs<br />
can be significant, <strong>the</strong> authors strongly<br />
recommend that a comprehensive site<br />
survey be carried out not only to determ<strong>in</strong>e<br />
<strong>the</strong> suitability of <strong>the</strong> site for <strong>the</strong><br />
species and <strong>the</strong> technology be<strong>in</strong>g considered<br />
but also to determ<strong>in</strong>e <strong>the</strong> economic<br />
feasibility of <strong>the</strong> project as well.<br />
Initial site assessment <strong>in</strong>formation and<br />
costs should be on direct <strong>in</strong>puts to <strong>the</strong><br />
project bus<strong>in</strong>ess plan to provide <strong>the</strong> necessary<br />
<strong>in</strong>sight <strong>in</strong>to <strong>the</strong> risk and <strong>the</strong> profitability<br />
of <strong>the</strong> offshore aquaculture<br />
venture.<br />
Acknowledgments<br />
The authors thank John Corb<strong>in</strong> of<br />
<strong>Aquaculture</strong> Plann<strong>in</strong>g & Advocacy<br />
LLC and two anonymous reviewers<br />
for <strong>the</strong>ir critical review and valuable<br />
contributions to <strong>the</strong> orig<strong>in</strong>al manuscript<br />
draft. This research was partially<br />
funded by past and current grants from<br />
<strong>the</strong> National Oceanic and Atmospheric<br />
Adm<strong>in</strong>istration (NOAA-NMAI No.<br />
NA06OAR4170238) and NOAA-<br />
MAP NA08OAR417826) and Sea<br />
Grant College Program (No. RLRA42).<br />
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Bonhomme, F., Colombo, L., Crosetti, D.,<br />
Danancher, D., García-Vázquez, E., Gilbey,<br />
J., Svåsand, T., Verspoor, E., Triantaphyllidis,<br />
C. 2007. Management options to reduce<br />
genetic impacts of aquaculture Activities.<br />
In: Genetic Impacts from <strong>Aquaculture</strong>:<br />
Meet<strong>in</strong>g <strong>the</strong> Challenge <strong>in</strong> Europe, 162-167.<br />
Norway: Bergen.<br />
U.S. Commission on Ocean Policy. 2004.<br />
An Ocean Bluepr<strong>in</strong>t for <strong>the</strong> <strong>21st</strong> <strong>Century</strong>.<br />
F<strong>in</strong>al Report. Wash<strong>in</strong>gton, DC. 646 pp.<br />
ISBN#0-9759462-0-X.<br />
Wu, R.S.S. 1995. The environmental impact<br />
of mar<strong>in</strong>e fish culture: Towards a susta<strong>in</strong>able<br />
future. Mar Pollut Bull. 31:159-166.<br />
May/June 2010 Volume 44 Number 3 35
PAPER<br />
A Case Study of an Offshore SeaStation®<br />
Sea Farm<br />
AUTHOR<br />
Gary F. Loverich<br />
Ocean Spar, LLC<br />
Introduction<br />
The author has been <strong>in</strong>volved <strong>in</strong><br />
<strong>the</strong> mar<strong>in</strong>e <strong>in</strong>dustry as a fisheries eng<strong>in</strong>eer<br />
specializ<strong>in</strong>g <strong>in</strong> commercial fish<strong>in</strong>g<br />
nets s<strong>in</strong>ce 1969 and sea farm<strong>in</strong>g<br />
cages s<strong>in</strong>ce 1988. The complementary<br />
nature of commercial fish<strong>in</strong>g technology<br />
and <strong>the</strong> development of an offshore<br />
sea farm<strong>in</strong>g <strong>in</strong>dustry led to a<br />
cont<strong>in</strong>uous study of possible cage<br />
configurations that had <strong>the</strong> potential<br />
for deployment at high-energy ocean<br />
sites. Throughout this narrative, <strong>the</strong><br />
term sea farm<strong>in</strong>g will be used to describe<br />
<strong>the</strong> rear<strong>in</strong>g of fish <strong>in</strong> <strong>the</strong> open<br />
ocean. The more common terms aquaculture<br />
or mariculture imply more<br />
precise control of <strong>the</strong> operations and<br />
environment, as might occur <strong>in</strong> sheltered<br />
bays and <strong>in</strong>land waters. In particular,<br />
<strong>the</strong> study of sea farm<strong>in</strong>g on <strong>the</strong><br />
basis of <strong>the</strong> author’s commercial fish<strong>in</strong>g<br />
experience led to <strong>the</strong> unique concept<br />
of us<strong>in</strong>g float<strong>in</strong>g spar buoys that<br />
serve as <strong>the</strong> basic structure to support a<br />
nett<strong>in</strong>g enclosure for grow<strong>in</strong>g fish. Simplyput,highlydampedsparbuoysare<br />
less <strong>in</strong>fluenced by surface waves than<br />
shallow draft surface floats (Berteaux,<br />
1991). Over time, this spar buoy sea<br />
cage technology has proven robust,<br />
workable, and economical and is commercially<br />
produced by Ocean Spar,<br />
LLC.<br />
The need for and challenges of offshore<br />
sea farm<strong>in</strong>g are well documented<br />
36 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
ABSTRACT<br />
Ocean Spar eng<strong>in</strong>eers have been test<strong>in</strong>g <strong>the</strong> SeaStation ® cage s<strong>in</strong>ce 1994. Recently,<br />
larger offshore sea farm<strong>in</strong>g ventures have been employ<strong>in</strong>g <strong>the</strong> SeaStation<br />
submersible cages for grow<strong>in</strong>g fish at ocean sites. Of particular <strong>in</strong>terest is <strong>the</strong><br />
case study of a larger system of SeaStation cages <strong>in</strong>stalled and operated off Keahole<br />
Po<strong>in</strong>t, Kona, Hawaii. The offshore site is subject to ocean-gyre currents of 1 m/s and<br />
50-year storm waves with significant wave heights of 9 m. The venture had six<br />
cages <strong>in</strong>stalled and arranged <strong>in</strong> a 2 × 3 moored array kept at a m<strong>in</strong>imum submergence<br />
of 10 m. The <strong>in</strong>dividual cages have unique buoyancy control for rais<strong>in</strong>g <strong>the</strong><br />
cage out of <strong>the</strong> water, so one half of <strong>the</strong> volume is exposed to air for clean<strong>in</strong>g and<br />
dry<strong>in</strong>g. This tactic also <strong>in</strong>creases <strong>the</strong> efficiency of crop harvest with m<strong>in</strong>imum effort<br />
by <strong>the</strong> farm operators and m<strong>in</strong>imum stress to <strong>the</strong> fish. As SeaStation cages were<br />
added to fill <strong>the</strong> six cage array, <strong>the</strong> last two cages were designed with an additional<br />
feature allow<strong>in</strong>g <strong>the</strong> cage to flip while submerged. The flip operation exchanged <strong>the</strong><br />
top and <strong>the</strong> bottom of <strong>the</strong> cage, so <strong>the</strong> entire cage could be cleaned by exposure to<br />
<strong>the</strong> sun and w<strong>in</strong>d. With <strong>the</strong> <strong>in</strong>creas<strong>in</strong>g number of cages, <strong>the</strong> grid system dynamics<br />
changed, and higher than expected currents foiled some of <strong>the</strong> operational strategies<br />
that were developed us<strong>in</strong>g <strong>the</strong> <strong>in</strong>dividual cages. This article documents <strong>the</strong> features,<br />
events, and <strong>in</strong>novative remedies that made this sea farm<strong>in</strong>g effort unique and<br />
worthy of note.<br />
<strong>in</strong> numerous academic, <strong>in</strong>dustrial,<br />
and government documents (Pittenger<br />
et al., 2007). The eng<strong>in</strong>eer<strong>in</strong>g design<br />
and development of <strong>the</strong> two Ocean<br />
Spar cage systems (Ocean Spar anchor<br />
tension and SeaStation® cages) are also<br />
described <strong>in</strong> <strong>the</strong> <strong>in</strong>dustry literature and<br />
especially <strong>in</strong> <strong>the</strong> article by Loverich and<br />
Forster (2000). Therefore, <strong>the</strong>re is little<br />
need to reiterate statements, ideas, <strong>the</strong>ories,<br />
or details described <strong>in</strong> past documents<br />
justify<strong>in</strong>g <strong>the</strong> necessity for <strong>the</strong><br />
development of an offshore sea farm<strong>in</strong>g<br />
<strong>in</strong>dustry or even describ<strong>in</strong>g <strong>the</strong> eng<strong>in</strong>eer<strong>in</strong>g<br />
effort which went <strong>in</strong>to <strong>the</strong><br />
cage designs (Loverich and Swanson,<br />
1993). Ra<strong>the</strong>r, this article is devoted to<br />
recent case studies of <strong>the</strong> SeaStation cage<br />
as applied to certa<strong>in</strong> offshore sea farm<strong>in</strong>g<br />
ventures. In particular, <strong>the</strong> SeaStation<br />
cage has proven itself with long-term<br />
<strong>in</strong>stallations <strong>in</strong> ocean locations; several<br />
of which have experienced direct or<br />
nearly direct hits from hurricanes<br />
and typhoons (Benetti et al., 2006).<br />
From 1989 to 1994, Ocean Spar’s<br />
eng<strong>in</strong>eer<strong>in</strong>g development of an offshore<br />
cage was focused on design and<br />
test<strong>in</strong>g of <strong>the</strong> anchor tensioned cage,<br />
now called <strong>the</strong> AquaSpar® cage. A<br />
total of 30 cages were <strong>in</strong>stalled, with<br />
two of <strong>the</strong> largest be<strong>in</strong>g 21,000 m 3 <strong>in</strong><br />
volume. The AquaSpar cage performs<br />
best <strong>in</strong> <strong>the</strong> gray area between low- and<br />
high-energy ocean sites and does especially<br />
well <strong>in</strong> areas of high current and<br />
moderate waves. The relatively recent<br />
emphasis on grow<strong>in</strong>g tropical or semitropical<br />
food fish offshore has <strong>in</strong>creased<br />
<strong>the</strong> <strong>in</strong>terest <strong>in</strong> <strong>the</strong> company’s o<strong>the</strong>r
design, <strong>the</strong> SeaStation cage, <strong>in</strong> part because<br />
of its ability to rema<strong>in</strong> and operate<br />
submerged beneath <strong>the</strong> ocean surface.<br />
Through test<strong>in</strong>g and operational experience,<br />
this design has proven to<br />
be a true offshore cage, and its application<br />
has become an eng<strong>in</strong>eer<strong>in</strong>g priority<br />
for Ocean Spar eng<strong>in</strong>eers.<br />
The Basic SeaStation Cage<br />
The SeaStation cage is best described<br />
as a cage with a central vertical<br />
spar buoy connected to a rigid horizontal<br />
r<strong>in</strong>g by syn<strong>the</strong>tic ropes (Figure 1).<br />
The arrangement is similar to a bicycle<br />
wheel where <strong>the</strong> axel is connected to<br />
<strong>the</strong> wheel rim by tensioned spokes.<br />
The taut syn<strong>the</strong>tic ropes connect<strong>in</strong>g<br />
<strong>the</strong> two rigid structures give <strong>the</strong><br />
cage its “semirigid” nature. Tension<br />
<strong>in</strong><strong>the</strong>spokesishighenoughtohold<br />
<strong>the</strong> structural components <strong>in</strong> place<br />
and results <strong>in</strong> a constant volume and<br />
shape even <strong>in</strong> high waves and high currents.<br />
Buoyancy is controlled by fill<strong>in</strong>g<br />
chambers <strong>in</strong> <strong>the</strong> central spar buoy with<br />
air or water. A ballast weight lowers <strong>the</strong><br />
effective center of gravity by act<strong>in</strong>g as a<br />
concentrated weight attached to <strong>the</strong><br />
bottom of <strong>the</strong> spar. The ballast weight<br />
is rigged to set <strong>the</strong> depth of cage sub-<br />
FIGURE 1<br />
The general configuration of all SeaStation<br />
cages. Some m<strong>in</strong>or details of construction<br />
and shape have changed as features have<br />
evolved over <strong>the</strong> past 15 years.<br />
}<br />
mergence <strong>in</strong> still water (Baldw<strong>in</strong> et al.,<br />
2000).<br />
While submerged, <strong>the</strong> stability of<br />
<strong>the</strong> SeaStation cage is ma<strong>in</strong>ta<strong>in</strong>ed by<br />
<strong>the</strong> vertical separation of <strong>the</strong> centers<br />
of buoyancy and gravity. When fully<br />
raised to <strong>the</strong> surface, stability is enhanced<br />
by <strong>the</strong> action of <strong>the</strong> buoyant<br />
rim sections act<strong>in</strong>g somewhat similar<br />
to <strong>the</strong> widely spaced hulls on a catamaran.<br />
Nett<strong>in</strong>g is attached to <strong>the</strong> structural<br />
spoke l<strong>in</strong>es connect<strong>in</strong>g <strong>the</strong> spar<br />
buoy and <strong>the</strong> rim. SeaStation cages<br />
can be adjusted to float with low freeboard<br />
and a small water plane or as<br />
submerged cages depend<strong>in</strong>g on <strong>the</strong><br />
need of <strong>the</strong> customer. In both deployment<br />
scenarios, <strong>the</strong> cage performs well<br />
<strong>in</strong> severe wave and high current environments,<br />
although shelter from confused<br />
surface seas is provided when<br />
fully submerged.<br />
From its <strong>in</strong>ception <strong>in</strong> 1994, <strong>the</strong>re<br />
have been approximately 50 <strong>in</strong>dividual<br />
SeaStation cages deployed. Some were<br />
studied strictly for eng<strong>in</strong>eer<strong>in</strong>g and operational<br />
test<strong>in</strong>g (Baldw<strong>in</strong> et al., 2000).<br />
These tests, hav<strong>in</strong>g limited budgets,<br />
had little or no possibility of <strong>in</strong>come<br />
but were considered important for<br />
cage evaluation or for <strong>in</strong>vestigat<strong>in</strong>g<br />
promis<strong>in</strong>g new species for domestication<br />
(Chambers and Howell, 2005).<br />
A few o<strong>the</strong>rs were <strong>in</strong>stalled by sea farmers<br />
who wanted to test one or two submersible<br />
cages at exposed sites where<br />
o<strong>the</strong>r types of cages would fail. Cage<br />
test<strong>in</strong>g supported by research grants<br />
<strong>in</strong> Spa<strong>in</strong>, Hawaii, and South Korea<br />
were later developed <strong>in</strong>to commercial<br />
farms by venture capitalists that added<br />
cages and <strong>in</strong>itiated <strong>in</strong>dustrial-scale<br />
operations. Each of <strong>the</strong>se pioneer<strong>in</strong>g<br />
enterprises has provided greater understand<strong>in</strong>g<br />
of <strong>the</strong> offshore operations<br />
and <strong>the</strong> impetus for enhancements<br />
to <strong>the</strong> technology of <strong>the</strong> SeaStation<br />
cage.<br />
The SeaStation cage has become<br />
<strong>the</strong> “poster child” for ocean aquaculture<br />
be<strong>in</strong>g pictured <strong>in</strong> many documents featur<strong>in</strong>g<br />
<strong>the</strong> pros and <strong>the</strong> cons of <strong>the</strong> offshore<br />
<strong>in</strong>dustry. As such, it has been<br />
recognized and evaluated by <strong>in</strong>dependent<br />
scientists and design teams treat<strong>in</strong>g<br />
it as a generic commodity (Perez<br />
et al., 2003). Most of <strong>the</strong> <strong>in</strong>stallations<br />
of SeaStation cages have been rout<strong>in</strong>e,<br />
and operations have been relatively<br />
troublefreeexceptfor<strong>the</strong>learn<strong>in</strong>g<br />
curve required of all new technologies<br />
<strong>in</strong>jected <strong>in</strong>to <strong>the</strong> diverse and hostile<br />
ocean environment. These rout<strong>in</strong>e <strong>in</strong>stallations<br />
require little discussion and<br />
are ra<strong>the</strong>r straight forward. The rema<strong>in</strong>der<br />
of this discussion will focus<br />
on recent design <strong>in</strong>novations, <strong>the</strong> operational<br />
flexibility of SeaStation cages,<br />
and some organizational difficulties<br />
that are often characteristic of new<br />
ventures. In particular, <strong>the</strong> SeaStation<br />
<strong>in</strong>stallation at Keahole Po<strong>in</strong>t on <strong>the</strong><br />
Island of Hawaii, State of Hawaii will<br />
be covered <strong>in</strong> detail, with occasional<br />
reference to <strong>in</strong>stallations at o<strong>the</strong>r sites.<br />
A Summary of Design and<br />
Operational Guidel<strong>in</strong>es<br />
When design<strong>in</strong>g offshore cages<br />
Ocean Spar eng<strong>in</strong>eers have followed<br />
some basic design guidel<strong>in</strong>es that are<br />
very useful to all those now work<strong>in</strong>g<br />
with sea farm<strong>in</strong>g at offshore sites or<br />
who are contemplat<strong>in</strong>g enter<strong>in</strong>g <strong>the</strong> offshore<br />
sea farm<strong>in</strong>g <strong>in</strong>dustry. Although<br />
many of <strong>the</strong>se guidel<strong>in</strong>es apply directly<br />
to <strong>the</strong> design of cages, o<strong>the</strong>rs have broad<br />
operational application. These guidel<strong>in</strong>es<br />
are summarized as follows:<br />
1) To be an expert, one has to know <strong>the</strong><br />
numerous wrong ways to approach a<br />
task as well as <strong>the</strong> few correct ways.<br />
2) In regard to offshore sea farm<strong>in</strong>g,<br />
if it was easy it would have been<br />
an <strong>in</strong>dustry long ago.<br />
May/June 2010 Volume 44 Number 3 37
3) The eng<strong>in</strong>eer<strong>in</strong>g mantra “Keep it<br />
Simple” multiplies several times<br />
over when consider<strong>in</strong>g structures,<br />
rigg<strong>in</strong>g, or operations <strong>in</strong> <strong>the</strong> ocean.<br />
4) Ocean conditions work 24/7 aga<strong>in</strong>st<br />
deployed structures. If <strong>the</strong>re is a design<br />
or constructional flaw <strong>in</strong> a system<br />
or component, given enough<br />
time <strong>in</strong> <strong>the</strong> water, <strong>the</strong> ocean conditions<br />
will exploit that flaw to cause<br />
failure.<br />
5) In <strong>the</strong> sea farm<strong>in</strong>g <strong>in</strong>dustry, success<br />
is proven over time. The fatal<br />
test often comes after public declarations<br />
of success.<br />
6) On land, humans control <strong>the</strong> plann<strong>in</strong>g<br />
and operations. In <strong>the</strong> sea,<br />
control over assets and ideas is rel<strong>in</strong>quished<br />
to and tested by Mo<strong>the</strong>r<br />
Nature.<br />
7) It is often difficult to teach new<br />
dogs old tricks. This <strong>in</strong>dustry will<br />
never get off <strong>the</strong> ground if <strong>the</strong><br />
same mistakes are made over and<br />
over aga<strong>in</strong> or if risks are not justified<br />
by experience.<br />
8) It is often difficult to teach old dogs<br />
new tricks. Be opened to reth<strong>in</strong>k<strong>in</strong>g<br />
older ideas and evaluat<strong>in</strong>g newer<br />
ones, but <strong>in</strong> <strong>the</strong> light of physics<br />
and past experience.<br />
9) There are two characteristics of<br />
<strong>the</strong> sea farm<strong>in</strong>g <strong>in</strong>dustry that frustrate<br />
and delay its evolution offshore<br />
and must be overcome or<br />
avoided.<br />
a) The tendency to retreat back to<br />
<strong>in</strong>shore cage technology and<br />
operational procedures that<br />
have previously failed and<br />
when applied offshore aga<strong>in</strong>,<br />
given enough time, will cont<strong>in</strong>ue<br />
to fail.<br />
b) The will<strong>in</strong>gness to be seduced<br />
by <strong>the</strong> latest untried and unproven<br />
novel cage system design.<br />
Every cage design has useful<br />
features and features that are<br />
38 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
troublesome. Work and learn<br />
with what has been proven.<br />
A Hawaii Case Study<br />
In 2003 and after 9 years of development<br />
and proof of concept, <strong>the</strong><br />
SeaStation cages were selected to be <strong>in</strong>stalled<br />
at a site offshore from Keahole<br />
Po<strong>in</strong>t on <strong>the</strong> Island of Hawaii. This specific<br />
use of <strong>the</strong> cages <strong>in</strong>itiated quick and<br />
<strong>in</strong>novative evolution of <strong>the</strong> SeaStation<br />
design through collaborations between<br />
Ocean Spar eng<strong>in</strong>eers and <strong>the</strong> sea farm<br />
owners. The chronology of this evolution<br />
<strong>in</strong> cage design and operation is<br />
important <strong>in</strong> understand<strong>in</strong>g <strong>the</strong> significance<br />
of this case study.<br />
The first cages at Keahole Po<strong>in</strong>t<br />
were <strong>in</strong>stalled <strong>in</strong> 2005. Although<br />
o<strong>the</strong>r SeaStation cage farms may have<br />
been <strong>in</strong> <strong>the</strong> water longer, used a different<br />
moor<strong>in</strong>g layout, and/or used larger<br />
SeaStation cages, <strong>the</strong> experience at<br />
Keahole Po<strong>in</strong>t provides an important<br />
case study because of <strong>the</strong> variety of design<br />
evolutions, <strong>the</strong> unique operational<br />
challenges, and <strong>the</strong> outcome of <strong>the</strong><br />
responses to <strong>the</strong>se challenges. The<br />
importance of <strong>the</strong> design guidel<strong>in</strong>es<br />
previously described is illustrated<br />
by this case study.<br />
Ocean Spar was contracted <strong>in</strong> 2005<br />
to <strong>in</strong>stall six SeaStation 3000 cages to<br />
grow Seriola rivoliana or Kahala <strong>in</strong><br />
2005. The operat<strong>in</strong>g strategy appeared<br />
to be one of rapid vertical <strong>in</strong>tegration<br />
<strong>in</strong>clud<strong>in</strong>g hatchery, operations, process<strong>in</strong>g,<br />
market<strong>in</strong>g, and distribution.<br />
The management was aggressive and<br />
capable. The Kahala were to be grown<br />
<strong>in</strong> submerged SeaStation cages moored<br />
as specified by <strong>the</strong> site permits.<br />
In <strong>the</strong> beg<strong>in</strong>n<strong>in</strong>g, <strong>the</strong> design and<br />
operational evolution of <strong>the</strong> SeaStation<br />
cages was accelerated by <strong>the</strong> aggressive<br />
management strategy, which encouraged<br />
<strong>the</strong> design and adoption of novel<br />
cage features and tactics. In this regard,<br />
<strong>the</strong> Ocean Spar eng<strong>in</strong>eers were challenged<br />
by reasonable design and operation<br />
requests that resulted <strong>in</strong> greater<br />
capabilities for <strong>the</strong> cages. The SeaStation<br />
cage ga<strong>in</strong>ed more useful features while at<br />
<strong>the</strong>sametimecont<strong>in</strong>uedevolv<strong>in</strong>gfrom<br />
simply an offshore cage to an offshore<br />
cagesystem.Thiswasseenasapositive<br />
development and a shared objective<br />
of Ocean Spar eng<strong>in</strong>eers, who welcomed<br />
<strong>the</strong> <strong>in</strong>novative and collaborative<br />
management style exhibited by <strong>the</strong><br />
venture.<br />
After years of eng<strong>in</strong>eer<strong>in</strong>g tests and<br />
small-scale <strong>in</strong>stallations, <strong>the</strong> SeaStation<br />
cage was at <strong>the</strong> po<strong>in</strong>t <strong>in</strong> its development<br />
where only <strong>the</strong> operation of a<br />
larger-scale sea farm would generate<br />
<strong>the</strong> evolution of improved operational<br />
features. Some features of SeaStation<br />
were created and were unique <strong>in</strong> <strong>the</strong><br />
sea farm<strong>in</strong>g <strong>in</strong>dustry. Given <strong>the</strong> very<br />
early success of <strong>the</strong> <strong>in</strong>itial two SeaStation<br />
cages <strong>in</strong>stalled at Keahole Po<strong>in</strong>t, it was<br />
reasonable to th<strong>in</strong>k that <strong>the</strong> success<br />
would cont<strong>in</strong>ue after all <strong>the</strong> cages were<br />
<strong>in</strong>stalled. However, as <strong>the</strong> cage system<br />
expanded, so did <strong>the</strong> complexity of<br />
farm operations and market demands<br />
for <strong>the</strong> product. More cages required<br />
more operational organization, and<br />
more cages put greater performance demands<br />
on <strong>the</strong> grid system anchor<strong>in</strong>g <strong>the</strong><br />
entire array of SeaStation cages.<br />
Ra<strong>the</strong>r quickly, <strong>the</strong> farm’s operational<br />
and equipment priorities<br />
changed. This complicated or halted<br />
<strong>the</strong> developments needed to fur<strong>the</strong>r<br />
improve operational efficiencies and<br />
facilitate learn<strong>in</strong>g by experience. Requests<br />
for specialized equipment<br />
sometimes changed on a weekly to<br />
monthly basis. Sometimes <strong>the</strong> equipment<br />
delivered was never used. From<br />
an eng<strong>in</strong>eer’s perspective, some of <strong>the</strong><br />
design and equipment requests to<br />
Ocean Spar were not fully vetted,
and <strong>the</strong> delivery schedules were unrealistic<br />
on <strong>the</strong> basis of <strong>the</strong> design<br />
complexity of <strong>the</strong> item.<br />
Soon after all of <strong>the</strong> cages were <strong>in</strong>stalled,<br />
<strong>the</strong> behavior of <strong>the</strong> grid moor<strong>in</strong>g<br />
system <strong>in</strong> response to <strong>the</strong> ocean<br />
conditions on <strong>the</strong> site became more<br />
dynamic. This behavior was not well<br />
understood by <strong>the</strong> operators, who had<br />
yet to optimize daily operations for <strong>the</strong><br />
completed cage system. High-priority<br />
design requests to Ocean Spar were<br />
abandoned when more immediate operat<strong>in</strong>g<br />
requirements took precedent.<br />
These <strong>in</strong>cluded a central feed station<br />
with submerged distribution of feed<br />
to all cages. Operational strategies,<br />
which might work well for a couple<br />
of cages, were foiled by <strong>the</strong> unanticipated<br />
difficulties of grow<strong>in</strong>g fish on<br />
<strong>the</strong> fully developed site.<br />
In addition, <strong>the</strong>re was less time to<br />
collaborate with <strong>the</strong> Ocean Spar eng<strong>in</strong>eers<br />
as <strong>the</strong> management structure of<br />
<strong>the</strong> farm changed and bus<strong>in</strong>ess became<br />
more complex. When most needed,<br />
communication became much more<br />
difficult as a result of a new cha<strong>in</strong> of<br />
command at <strong>the</strong> sea farm. Fail<strong>in</strong>g to<br />
take <strong>the</strong> time to understand <strong>the</strong> sources<br />
of problems and possible solutions,<br />
farm managers started exam<strong>in</strong><strong>in</strong>g<br />
novel cage designs and reth<strong>in</strong>k<strong>in</strong>g<br />
gravity cage technology. Eventually,<br />
<strong>the</strong> <strong>in</strong>vestors lost confidence <strong>in</strong> be<strong>in</strong>g<br />
able to economically raise fish <strong>in</strong> sea<br />
cages at <strong>the</strong> Keahole Po<strong>in</strong>t site.<br />
More recently, Ocean Spar personnel<br />
have determ<strong>in</strong>ed that fish could be<br />
profitably raised at Keahole Po<strong>in</strong>t us<strong>in</strong>g<br />
SeaStation cages under a more<br />
modest bus<strong>in</strong>ess plan, similar to o<strong>the</strong>r<br />
successful SeaStation sea farms. In<br />
December 2009, <strong>the</strong> majority owners<br />
of Ocean Spar purchased <strong>the</strong> Keahole<br />
Po<strong>in</strong>t site and started a new enterprise,<br />
which is at this time too new for comment.<br />
The follow<strong>in</strong>g discussion will<br />
provide a more detailed eng<strong>in</strong>eer<strong>in</strong>g<br />
and operational history of <strong>the</strong> Keahole<br />
Po<strong>in</strong>t deployment of <strong>the</strong> SeaStation<br />
cages.<br />
The Features of Keahole<br />
Po<strong>in</strong>t and SeaStation Cages<br />
The Keahole Po<strong>in</strong>t site is located<br />
about 1 mile offshore and <strong>in</strong> water<br />
depths that range from 59 to approximately<br />
68 m over <strong>the</strong> permitted area.<br />
With <strong>the</strong> exception of two small float<strong>in</strong>g<br />
gravity cages, <strong>the</strong> site permit did<br />
not allow floats moored permanently<br />
on <strong>the</strong> surface of <strong>the</strong> ocean. The bottom<br />
characteristics were orig<strong>in</strong>ally described<br />
as lava rock and some sand<br />
patches, but with little o<strong>the</strong>r detailed<br />
<strong>in</strong>formation provided. Local currents<br />
are generated by cyclical ocean gyres,<br />
local bathymetry, and wea<strong>the</strong>r. The accelerated<br />
bus<strong>in</strong>ess plan did not allow<br />
time for current or wave measurements<br />
that extended beyond 4 weeks; however,<br />
that scenario had been typical of<br />
every Ocean Spar <strong>in</strong>stallation over <strong>the</strong><br />
past 20 years, so it was thought to be<br />
“bus<strong>in</strong>ess as usual.” Ocean Spar measured<br />
currents as high as 0.70 m/s by<br />
deploy<strong>in</strong>g a record<strong>in</strong>g current meter.<br />
From published wave data and from<br />
<strong>the</strong> analysis of a 50-year storm, it was<br />
estimated that such an event would<br />
produce significant wave heights of<br />
n<strong>in</strong>e meters (Rocheleau, 1979). There<br />
wasnosupport<strong>in</strong>gdatatosuggest<br />
extreme waves might be smaller at<br />
Keahole Po<strong>in</strong>t. Therefore, <strong>the</strong> cage system<br />
was designed for possible wave<br />
heights of n<strong>in</strong>e meters, concurrent with<br />
current velocity equal to 0.75 m/s,<br />
runn<strong>in</strong>g <strong>in</strong> <strong>the</strong> same direction as <strong>the</strong><br />
waves. As a matter of policy, Ocean<br />
Spar doubles <strong>the</strong> actual drag of each<br />
cage for all structural and moor<strong>in</strong>g calculations<br />
because some biofoul<strong>in</strong>g will<br />
always be present on a cage, and it is<br />
never known how regularly <strong>the</strong> cages<br />
will be cleaned.<br />
Theentirecageandmoor<strong>in</strong>gsystem<br />
was designed and assembled as<br />
<strong>the</strong> current measurements were be<strong>in</strong>g<br />
recorded, so an <strong>in</strong>creased safety factor<br />
was also designed <strong>in</strong>to <strong>the</strong> system to<br />
compensate for unknowns. After all<br />
<strong>the</strong> cages were deployed, subsequent<br />
measurements <strong>in</strong>dicated ocean-gyre<br />
currentsashighas1.04m/s.The<br />
cages’ ability to withstand <strong>the</strong> higher<br />
current verified numerical model<strong>in</strong>g<br />
of <strong>the</strong> structure and provided a valuable<br />
eng<strong>in</strong>eer<strong>in</strong>g test. When <strong>the</strong> higher<br />
current events occurred, farm operations<br />
were complicated because <strong>the</strong><br />
peak currents could last for periods as<br />
short as a few days or for periods measured<br />
<strong>in</strong> weeks.<br />
The Grid Moor<strong>in</strong>g System<br />
The bottom footpr<strong>in</strong>t encompass<strong>in</strong>g<br />
<strong>the</strong> entire Keahole Po<strong>in</strong>t sea farm permit<br />
area was too small to accommodate<br />
<strong>in</strong>dependently moored cages so a grid<br />
moor<strong>in</strong>g array was selected to fit <strong>the</strong><br />
site. Ocean Spar’s preferred anchor<br />
l<strong>in</strong>e scope ratios of at least 6:1 for<br />
high current sites could not be accommodated<strong>in</strong>side<strong>the</strong>permittedarea.<br />
Hence, <strong>the</strong> grid system was designed<br />
us<strong>in</strong>g a 4:1 scope ratio for anchor l<strong>in</strong>es,<br />
which connected to 2.5-ton Delta<br />
Flipper drag embedment anchors.<br />
The grid system was composed of<br />
moor<strong>in</strong>g l<strong>in</strong>es and ropes fram<strong>in</strong>g <strong>the</strong><br />
2 × 3 moor<strong>in</strong>g array or grid. Calculation<br />
of total submerged buoyancy was<br />
based on <strong>the</strong> orig<strong>in</strong>al current measurements<br />
show<strong>in</strong>g a maximum speed of<br />
0.75 m/s. A s<strong>in</strong>gle 3000-m 3 SeaStation<br />
cage occupied each cell of <strong>the</strong> grid<br />
and was connected by four pennants<br />
(Figure 2). The grid was submerged<br />
May/June 2010 Volume 44 Number 3 39
FIGURE 2<br />
A f<strong>in</strong>ite element model of <strong>the</strong> six cage grid system used at Keahole Po<strong>in</strong>t. This early layout has<br />
been simplified for clarity and is represented <strong>in</strong> still water.<br />
at 10 m depth, which was also <strong>the</strong><br />
approximate location of <strong>the</strong> top of<br />
<strong>the</strong> cage <strong>in</strong> still water.<br />
The sea farm started with two cages<br />
and gradually <strong>in</strong>creased to a total of<br />
eight SeaStations. The last two cages<br />
could not be connected directly to <strong>the</strong><br />
orig<strong>in</strong>al six cell array, so <strong>the</strong>y were <strong>in</strong>dependently<br />
moored with<strong>in</strong> <strong>the</strong> legal farm<br />
boundaries. These two cages figure little<br />
<strong>in</strong> <strong>the</strong> eng<strong>in</strong>eer<strong>in</strong>g performance of<br />
<strong>the</strong> system but did <strong>in</strong>crease <strong>the</strong> work<br />
load of <strong>the</strong> staff.<br />
Buoyancy Control<br />
<strong>in</strong> SeaStation<br />
The SeaStation cages each have a<br />
fixed buoyancy chamber <strong>in</strong>sur<strong>in</strong>g<br />
that a cage will float to <strong>the</strong> surface<br />
should it ever become decoupled<br />
from its ballast weight. When submerged,<br />
a cage s<strong>in</strong>ks until <strong>the</strong> ballast<br />
weight hits bottom and <strong>the</strong> cage floats<br />
a fixed distance above at its designed<br />
operat<strong>in</strong>g depth, as determ<strong>in</strong>ed by <strong>the</strong><br />
ballast pennant length. This fixed<br />
buoyancy chamber is a pressure hull<br />
that can withstand cont<strong>in</strong>uous submergence<br />
to greater depths than most<br />
sea farms ever wish to operate. The air<br />
volume <strong>in</strong>side <strong>the</strong> fixed buoyancy<br />
40 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
chamber is not open to ambient sea<br />
pressure and is constant until crush<br />
depth is reached. In contrast, <strong>the</strong> bottom<br />
portion of <strong>the</strong> spar buoy has variable<br />
buoyancy controlled by <strong>the</strong> farm<br />
operators and when fully filled with<br />
air will lift <strong>the</strong> cage to <strong>the</strong> surface<br />
level while also lift<strong>in</strong>g <strong>the</strong> ballast<br />
weight off bottom. Variable and fixed<br />
buoyancy is a simple system that works<br />
well and is a major advantage of<br />
SeaStation cages.<br />
In response to design requests for<br />
<strong>the</strong> Keahole Po<strong>in</strong>t site, Ocean Spar<br />
eng<strong>in</strong>eers modified cages by <strong>in</strong>creas<strong>in</strong>g<br />
variable buoyancy enough to raise <strong>the</strong><br />
cages until <strong>the</strong> rim floated on <strong>the</strong> surface.<br />
This raised <strong>the</strong> total amount of variable<br />
buoyancy for <strong>the</strong> entire eight cage<br />
system to approximately 50,000 kgf.<br />
This change benefited net clean<strong>in</strong>g and<br />
offered <strong>the</strong> advantage of expos<strong>in</strong>g <strong>the</strong><br />
entire top half of <strong>the</strong> cage so that <strong>the</strong> nett<strong>in</strong>g<br />
could be air dried <strong>in</strong> <strong>the</strong> sun and<br />
ocean breeze while <strong>the</strong> fish rema<strong>in</strong>ed<br />
<strong>in</strong><strong>the</strong>lowerhalfof<strong>the</strong>cage(Figure3).<br />
This proved to be a unique clean<strong>in</strong>g<br />
strategy not available <strong>in</strong> any o<strong>the</strong>r cage<br />
design. With <strong>the</strong> top half of <strong>the</strong> cage<br />
out of <strong>the</strong> water, <strong>the</strong> submerged portion<br />
was cleaned by divers us<strong>in</strong>g hydraulic<br />
net cleaners. The first four SeaStation<br />
FIGURE 3<br />
Two of <strong>the</strong> first cages <strong>in</strong>stalled at Keahole Po<strong>in</strong>t,<br />
each float<strong>in</strong>g at rim level. The two gravity nursery<br />
cages are float<strong>in</strong>g <strong>in</strong> <strong>the</strong> background.<br />
cages for <strong>the</strong> site were built with this<br />
new and very useful feature.<br />
Theslopedbottomhalfof<strong>the</strong><br />
SeaStation cage served to force dead<br />
fish, termed morts, to <strong>the</strong> bottom of<br />
<strong>the</strong> cage where <strong>the</strong>y could be collected<br />
from <strong>in</strong>side or outside of <strong>the</strong> cage depend<strong>in</strong>g<br />
on diver preference. There<br />
was no requirement for divers to enter<br />
<strong>the</strong> cage and swim over a broad net<br />
bottom <strong>in</strong> search of morts. Fur<strong>the</strong>rmore,<br />
Ocean Spar eng<strong>in</strong>eers, given<br />
<strong>the</strong> ability to raise <strong>the</strong> cages to <strong>the</strong> surface,<br />
were also able to test new hardware<br />
to air lift morts from <strong>the</strong> small<br />
conical area at <strong>the</strong> bottom of <strong>the</strong> cage<br />
to save collection time.<br />
The <strong>in</strong>novative partnership between<br />
<strong>the</strong> companies allowed o<strong>the</strong>r<br />
ideas to be tested. Cages five and six<br />
were redesigned to be totally flipped<br />
upside down so both <strong>the</strong> top and<br />
<strong>the</strong> bottom of <strong>the</strong> cages could be alternately<br />
air dried. Flipp<strong>in</strong>g or capsiz<strong>in</strong>g<br />
was achieved by a tactic of fill<strong>in</strong>g<br />
<strong>the</strong> bottom ballast chamber with air<br />
while allow<strong>in</strong>g <strong>the</strong> top chamber to<br />
flood. Notably, <strong>the</strong> f<strong>in</strong>gerl<strong>in</strong>gs necessary<br />
to stock <strong>the</strong> new cages were already<br />
be<strong>in</strong>g raised <strong>in</strong> <strong>the</strong> hatchery, which<br />
added a time constra<strong>in</strong>t to <strong>the</strong> order.<br />
The tight delivery schedule required<br />
a compromise <strong>in</strong> designed
stability, which proved practical at first,<br />
but troublesome later. To elim<strong>in</strong>ate<br />
<strong>the</strong> need for disconnect<strong>in</strong>g <strong>the</strong> ballast<br />
weights from <strong>the</strong> spar, <strong>the</strong> typical s<strong>in</strong>gle<br />
ballast design shown <strong>in</strong> Figure 1<br />
was replaced with two smaller ballast<br />
weights shown <strong>in</strong> Figure 4. Each was<br />
suspended from <strong>the</strong> rim rigg<strong>in</strong>g on a<br />
special swivel. Then after <strong>the</strong> two grid<br />
pennants were removed, <strong>the</strong> o<strong>the</strong>r<br />
two pennants acted as a gimbaled axis<br />
allow<strong>in</strong>g <strong>the</strong> cages to flip 180° (Figure<br />
4). The flip tactic is always accomplished<br />
with <strong>the</strong> cage fully submerged,<br />
and although remov<strong>in</strong>g two grid pennants<br />
from <strong>the</strong> rim requires some diver<br />
activity, <strong>the</strong> reduction <strong>in</strong> diver clean<strong>in</strong>g<br />
effort greatly outweighed <strong>the</strong> extra<br />
time needed to flip a cage.<br />
The downside to this arrangement<br />
was <strong>the</strong> reduction <strong>in</strong> hydrostatic stability<br />
of <strong>the</strong> SeaStation when surfaced.<br />
The ballast attachment po<strong>in</strong>ts<br />
now at <strong>the</strong> rim level moved <strong>the</strong> virtual<br />
center of gravity up <strong>the</strong> spar buoy and<br />
decreased <strong>the</strong> overall stability of <strong>the</strong><br />
cage especially with <strong>the</strong> rim surfaced.<br />
The redesigned cages were successfully<br />
flipped several times prov<strong>in</strong>g <strong>the</strong><br />
concept and arguably <strong>the</strong> operational<br />
utility of <strong>the</strong> feature; that is, <strong>the</strong> cage<br />
clean<strong>in</strong>g can always be done <strong>in</strong> shallower<br />
water.<br />
FIGURE 4<br />
This concept draw<strong>in</strong>g of <strong>the</strong> Flip SeaStation<br />
illustrates <strong>the</strong> cages ability to rotate 180°<br />
around an imag<strong>in</strong>ary axis between <strong>the</strong> ballast<br />
weight attachment po<strong>in</strong>ts.<br />
This feature <strong>in</strong>creased <strong>the</strong> potential<br />
capabilities of SeaStation. Later alternative<br />
flip details and o<strong>the</strong>r means<br />
to <strong>in</strong>crease cage surface stability were<br />
developed, although <strong>the</strong>se features<br />
could not be retrofitted to <strong>the</strong> cages<br />
at Keahole Po<strong>in</strong>t. This enhanced surface<br />
stability is now standard for<br />
SeaStation cages. The flip capability<br />
although useful was never fully<br />
exploited at Keahole Po<strong>in</strong>t.<br />
Nursery Nets<br />
All <strong>the</strong> SeaStation cages were<br />
constructed us<strong>in</strong>g 51 mm stretch ×<br />
1.9 mm diameter Ultra Cross Dynema<br />
nett<strong>in</strong>g to keep <strong>the</strong> system drag as low<br />
as possible, although any type of nett<strong>in</strong>g<br />
can be used. This mesh size was<br />
too large to reta<strong>in</strong> Kahala f<strong>in</strong>gerl<strong>in</strong>gs,<br />
so a nursery strategy was needed to<br />
grow fish to a larger stock<strong>in</strong>g size.<br />
Orig<strong>in</strong>ally, f<strong>in</strong>gerl<strong>in</strong>gs from <strong>the</strong> hatchery<br />
were transferred to small mesh, surface<br />
gravity cages for about 30 days,<br />
until <strong>the</strong>y grew large enough to be<br />
transferred <strong>in</strong>to <strong>the</strong> larger-mesh cages.<br />
The orig<strong>in</strong>al nursery cage strategy did<br />
not work well at this site because <strong>the</strong><br />
wave and <strong>the</strong> current conditions were<br />
too extreme for ma<strong>in</strong>ta<strong>in</strong><strong>in</strong>g float<strong>in</strong>g<br />
gravity cages and <strong>the</strong>y were quickly<br />
abandoned.<br />
The situation was remedied by<br />
us<strong>in</strong>g nursery nets supplied by Ocean<br />
Spar, each temporarily mounted <strong>in</strong>side<br />
a SeaStation cage (Figure 5). The nursery<br />
nets that wrap around <strong>the</strong> spar and<br />
are connected to <strong>the</strong> rim by ropes had<br />
been used successfully on many o<strong>the</strong>r<br />
SeaStation <strong>in</strong>stalls. The nursery cages<br />
were <strong>in</strong>itially designed for a volume of<br />
300 m 3 but were eventually supplied<br />
<strong>in</strong> 600- and 900-m 3 volumes. Divers<br />
could easily <strong>in</strong>stall and remove <strong>the</strong>se<br />
nets through zippered open<strong>in</strong>gs <strong>in</strong> <strong>the</strong><br />
SeaStation cage. The elim<strong>in</strong>ation of<br />
FIGURE 5<br />
A typical SeaStation cage with a nursery net.<br />
For clarity, <strong>the</strong> tensioned l<strong>in</strong>es between <strong>the</strong><br />
nursery net and <strong>the</strong> SeaStation rim are not<br />
shown.<br />
<strong>the</strong> gravity nursery cages allowed <strong>the</strong><br />
two additional SeaStations to be <strong>in</strong>stalled,<br />
mak<strong>in</strong>g a total of eight, without<br />
violat<strong>in</strong>g <strong>the</strong> site permit.<br />
Fish Harvest<br />
The precise control of free board<br />
and <strong>the</strong> slop<strong>in</strong>g bottom of SeaStation<br />
cages offers some significant advantages<br />
for harvest<strong>in</strong>g <strong>the</strong> stock. Both<br />
of <strong>the</strong>se features were used to develop<br />
two new harvest techniques at Keahole<br />
Po<strong>in</strong>t.<br />
When <strong>in</strong> higher densities, fish were<br />
harvested by <strong>the</strong> use of a nett<strong>in</strong>g cone<br />
mounted <strong>in</strong>side of SeaStation. With<br />
<strong>the</strong> wide end opened and po<strong>in</strong>t<strong>in</strong>g toward<br />
<strong>the</strong> surface, <strong>the</strong> entire cone surrounds<br />
<strong>the</strong> central spar buoy. A fish<br />
pump and hose attaches to <strong>the</strong> bottom<br />
end of <strong>the</strong> cone. With <strong>the</strong> harvest cone<br />
<strong>in</strong>stalled, <strong>the</strong> submerged cage is raised<br />
by <strong>the</strong> addition of air to <strong>the</strong> spar buoy<br />
until <strong>the</strong> top end of <strong>the</strong> harvest cone is<br />
above <strong>the</strong> water surface, and <strong>the</strong> captured<br />
fish are concentrated at <strong>the</strong> bottom<br />
of <strong>the</strong> cone. They can <strong>the</strong>n be<br />
pumped aboard ship for transport to<br />
shore.<br />
Several rais<strong>in</strong>g and lower<strong>in</strong>g sequences<br />
might be needed to harvest<br />
May/June 2010 Volume 44 Number 3 41
<strong>the</strong> fish required for market (Figure<br />
6). This first stage harvest worked<br />
well, and Ocean Spar cont<strong>in</strong>ued to<br />
develop <strong>the</strong> technique and equipment<br />
fur<strong>the</strong>r with ideas com<strong>in</strong>g from o<strong>the</strong>r<br />
sea farmers (Figure 7). As fish are harvested<br />
from <strong>the</strong> cage, <strong>the</strong> harvest cone<br />
technique becomes less efficient because<br />
fewer fish occupy a larger space.<br />
Theconeharvesttechniquedoes<br />
not take advantage of a major feature<br />
of SeaStation. Early <strong>in</strong> <strong>the</strong> development<br />
of SeaStation cages, it was realized<br />
that fish could be concentrated<br />
for harvest or grad<strong>in</strong>g by slowly rais<strong>in</strong>g<br />
<strong>the</strong> cage to <strong>the</strong> surface. The controllable<br />
accent speed and <strong>the</strong> stable<br />
FIGURE 6<br />
The harvest net used at Keahole Po<strong>in</strong>t is shown<br />
<strong>in</strong>side of <strong>the</strong> SeaStation cage after <strong>the</strong> cage has<br />
been raised to <strong>the</strong> surface.<br />
FIGURE 7<br />
A later evolution of <strong>the</strong> harvest cone preferred<br />
for use <strong>in</strong> <strong>the</strong> Spanish SeaStation cages. Notice<br />
<strong>the</strong> rigid <strong>in</strong>terface act<strong>in</strong>g to connect <strong>the</strong> net with<br />
<strong>the</strong> pump hose.<br />
42 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
shape of <strong>the</strong> cage reduce fish stress as<br />
<strong>the</strong>cageisraisedwhileat<strong>the</strong>same<br />
time <strong>the</strong> cage volume is reduced by<br />
half. This volume reduction was <strong>the</strong><br />
basis for a second harvest technique.<br />
To efficiently harvest <strong>the</strong> last few<br />
fish from <strong>the</strong> cage required a different<br />
technique. A se<strong>in</strong><strong>in</strong>g operation was<br />
developed by Ocean Spar with <strong>the</strong> rim<br />
at <strong>the</strong> surface and <strong>the</strong> spar buoy serv<strong>in</strong>g<br />
as an axle around which a special<br />
“sweep” se<strong>in</strong>e was wrapped and <strong>the</strong>n<br />
unwrapped. Hav<strong>in</strong>g one end of <strong>the</strong><br />
se<strong>in</strong>e be<strong>in</strong>g held stationary while <strong>the</strong><br />
o<strong>the</strong>r end moves around <strong>the</strong> <strong>in</strong>side<br />
perimeter of <strong>the</strong> cage crowds <strong>the</strong> fish<br />
for harvest aga<strong>in</strong>st <strong>the</strong> stationary end.<br />
Fur<strong>the</strong>r collaps<strong>in</strong>g of <strong>the</strong> se<strong>in</strong>e concentrates<br />
fish for pump<strong>in</strong>g to a boat which<br />
is moored along side <strong>the</strong> rim.<br />
The SeaStation is uniquely configured<br />
for se<strong>in</strong>e harvest. The bottom of<br />
<strong>the</strong> se<strong>in</strong>e is sloped to match <strong>the</strong> bottom<br />
of <strong>the</strong> cage. This sloped bottom enhanced<br />
<strong>the</strong> efficiency of <strong>the</strong> se<strong>in</strong>e by locat<strong>in</strong>g<br />
<strong>the</strong> shallow end at <strong>the</strong> perimeter,<br />
where <strong>the</strong> tow velocity is greatest, and<br />
<strong>the</strong> deeper, higher drag part of <strong>the</strong><br />
se<strong>in</strong>e near <strong>the</strong> spar “axel,” where <strong>the</strong><br />
tow velocity is near zero. The efficiency<br />
comes not only from <strong>the</strong> lower motive<br />
force required to move <strong>the</strong> se<strong>in</strong>e but<br />
also from better contact between <strong>the</strong><br />
se<strong>in</strong>e and <strong>the</strong> cage bottom because of<br />
<strong>the</strong> faster mov<strong>in</strong>g end hav<strong>in</strong>g less tendency<br />
to lift off bottom and allow<strong>in</strong>g<br />
<strong>the</strong> fish to escape.<br />
Confound<strong>in</strong>g Occurrences<br />
The <strong>in</strong>itial progress at <strong>the</strong> Keahole<br />
Po<strong>in</strong>t site and positive attitudes toward<br />
SeaStation cages slowly changed after<br />
all <strong>the</strong> cages were <strong>in</strong>stalled. Improvements<br />
and evolution <strong>in</strong> operational<br />
procedures were halted <strong>in</strong> response to<br />
new, dynamic changes <strong>in</strong> <strong>the</strong> behavior<br />
of <strong>the</strong> grid system.<br />
As previously stated, <strong>the</strong> maximum<br />
current at <strong>the</strong> site exceeded <strong>the</strong> expected<br />
currents. Drag was <strong>in</strong>creased<br />
by <strong>the</strong> temporary <strong>in</strong>stallation of larger<br />
nursery nets <strong>in</strong>to some cages as <strong>the</strong>y<br />
were restocked. The small mesh nursery<br />
nets have nearly <strong>the</strong> same drag as<br />
a SeaStation cage itself. For a fully<br />
stocked farm with perhaps several different<br />
cohorts of fish be<strong>in</strong>g raised at <strong>the</strong><br />
same time, it would not be uncommon<br />
to see at least one nursery net <strong>in</strong>stalled<br />
<strong>in</strong> <strong>the</strong> system at all times. As higher<br />
than expected currents became more<br />
frequent, <strong>the</strong> system drag <strong>in</strong>creased.<br />
The drag issue was exacerbated fur<strong>the</strong>r<br />
by a sea farm company decision to stop<br />
clean<strong>in</strong>g <strong>the</strong> cages and concentrate on<br />
<strong>the</strong> requirements of rear<strong>in</strong>g <strong>the</strong> fish.<br />
When faster mov<strong>in</strong>g water arrived,<br />
it was not uncommon to see <strong>the</strong> entire<br />
system submerged to greater depths<br />
than <strong>in</strong>itially observed. With greater<br />
biofoul<strong>in</strong>g and <strong>the</strong> addition of nursery<br />
nets, even <strong>in</strong> lower currents, <strong>the</strong> cages<br />
submerged to greater depths than orig<strong>in</strong>ally<br />
planned, and <strong>the</strong>y did so more<br />
frequently and for longer periods of<br />
time. The cages would submerge<br />
until <strong>the</strong>y reached an equilibrium<br />
depth where <strong>the</strong> current was lower or<br />
where buoyancy, drag, and moor<strong>in</strong>g<br />
forces balanced. For some cages, this<br />
could be anywhere from <strong>the</strong> designed<br />
depth of 10–30 m deep or greater.<br />
These greater depths had been predicted<br />
by numerical model<strong>in</strong>g, but<br />
<strong>the</strong> longer duration of <strong>the</strong> currents was<br />
not expected. Fortunately, SeaStation<br />
cages are capable of withstand<strong>in</strong>g<br />
great submergence, and <strong>the</strong> fish were<br />
not adversely affected by <strong>the</strong> chang<strong>in</strong>g<br />
depths.<br />
However, <strong>the</strong> harvest techniques<br />
developed at Keahole Po<strong>in</strong>t required<br />
a near vertical spar angle. But with<br />
<strong>the</strong> <strong>in</strong>creased depths of <strong>the</strong> grid system,<br />
<strong>the</strong> vertical orientation was sometimes
compromised, especially when <strong>the</strong> Flip<br />
cages were surfaced. In <strong>the</strong> stronger<br />
current, rais<strong>in</strong>g a s<strong>in</strong>gle cage caused it<br />
to pull aga<strong>in</strong>st <strong>the</strong> submerged grid system<br />
by its upstream pennants, and <strong>in</strong><br />
so do<strong>in</strong>g, it would heel to beyond its<br />
workable angle (Figure 8).<br />
FIGURE 8<br />
One of <strong>the</strong> Flip SeaStation cages shown heel<strong>in</strong>g<br />
as it is raised to <strong>the</strong> surface and pulls aga<strong>in</strong>st <strong>the</strong><br />
submerged grid system.<br />
Discussion<br />
The early success of <strong>the</strong> Keahole<br />
Po<strong>in</strong>t sea farm <strong>in</strong> terms of operations,<br />
fish quality, and market<strong>in</strong>g promised future<br />
success as <strong>the</strong> number of SeaStation<br />
cages <strong>in</strong>creased to <strong>the</strong> permitted capacity.<br />
However, <strong>the</strong> operational techniques<br />
learned while work<strong>in</strong>g with a<br />
few cages do not necessarily scale up<br />
when work<strong>in</strong>g with a completed cage<br />
system or even with larger cages. The<br />
need to produce more product <strong>in</strong> coord<strong>in</strong>ation<br />
with <strong>in</strong>creas<strong>in</strong>g market<br />
demand often results <strong>in</strong> operational<br />
difficulties for any new bus<strong>in</strong>ess venture.<br />
The economic pressure to realize<br />
a profit cannot be underestimated as a<br />
major <strong>in</strong>fluence to accelerate sales and<br />
reduce costs. From <strong>the</strong> perspective of<br />
an eng<strong>in</strong>eer and constra<strong>in</strong><strong>in</strong>g discussion<br />
to hardware and its use, h<strong>in</strong>d<br />
sight suggests that declar<strong>in</strong>g “success<br />
too early” prevented a more cautious<br />
approach to learn<strong>in</strong>g <strong>the</strong> characteris-<br />
tics of <strong>the</strong> site and equipment. Recogniz<strong>in</strong>g<br />
<strong>the</strong>re is a learn<strong>in</strong>g curve could<br />
have been one part of a strategy result<strong>in</strong>g<br />
<strong>in</strong> a more successful longer term<br />
outcome.<br />
SeaStation Stability<br />
As described above, <strong>the</strong> <strong>in</strong>herent<br />
stability of <strong>the</strong> SeaStation cages was<br />
adversely affected by occurrences, necessities,<br />
and strategies unrelated to<br />
<strong>the</strong> design of SeaStation cages. The<br />
generous 50,000 kgf of reserve buoyancy<br />
available <strong>in</strong> <strong>the</strong> eight cages was<br />
not used to adjust to chang<strong>in</strong>g ocean<br />
cycles. The reasons for this are not apparent,<br />
but at least a partial use of this<br />
available reserve buoyancy would<br />
have raised <strong>the</strong> work<strong>in</strong>g depth of <strong>the</strong><br />
entire grid system and <strong>in</strong>creased <strong>the</strong><br />
stability of <strong>the</strong> cages when surfaced,<br />
much <strong>the</strong> same as had happened<br />
when only a few cages were attached<br />
to <strong>the</strong> grid or when <strong>the</strong> system drag<br />
was lower.<br />
Ocean Spar has designed, built,<br />
and <strong>in</strong>stalled SeaStation cages as large<br />
as 6800 m 3 (Figure 9) and now have<br />
cage designs with up to 15,000 m 3<br />
grow<strong>in</strong>g volume. Just by <strong>in</strong>creas<strong>in</strong>g<br />
<strong>the</strong> geometric scale of <strong>the</strong> components<br />
<strong>in</strong> <strong>the</strong>se larger cages, <strong>the</strong> <strong>in</strong>herent surface<br />
FIGURE 9<br />
SeaStation 5400 was <strong>in</strong>stalled off <strong>the</strong> coast of<br />
South Korea <strong>in</strong> May of 2006. This cage represents<br />
<strong>the</strong> first design larger than <strong>the</strong> 3000 series.<br />
stability of <strong>the</strong> cage has been significantly<br />
<strong>in</strong>creased. Yet if reserve buoyancy<br />
was not utilized at Keahole Po<strong>in</strong>t, even<br />
<strong>the</strong> new and larger cages would have<br />
behaved <strong>in</strong> exactly <strong>the</strong> same way, a<br />
s<strong>in</strong>gle cage try<strong>in</strong>g to raise <strong>the</strong> entire<br />
system and <strong>in</strong> so do<strong>in</strong>g heel<strong>in</strong>g over<br />
too far from vertical to operate.<br />
Cage Clean<strong>in</strong>g<br />
As illustrated at <strong>the</strong> Keahole Po<strong>in</strong>t<br />
site, but also at nearly all o<strong>the</strong>r operat<strong>in</strong>g<br />
farms, net clean<strong>in</strong>g is of utmost<br />
importance. The high drag of cages<br />
heavy with biofoul<strong>in</strong>g contributed to<br />
over power<strong>in</strong>g <strong>the</strong> submerged grid<br />
system and <strong>the</strong> fixed buoyancy <strong>in</strong>herent<br />
<strong>in</strong> each SeaStation cage. Clean<strong>in</strong>g<br />
nets if cont<strong>in</strong>ued would have m<strong>in</strong>imized<br />
if not elim<strong>in</strong>ated much of <strong>the</strong><br />
difficulty experienced at Keahole<br />
Po<strong>in</strong>t (Figure 10). Until adequate antifoulant<br />
components are developed, <strong>the</strong><br />
best strategy at offshore sites for cage<br />
clean<strong>in</strong>g is to employ or contract that<br />
job out to a crew of divers or operators<br />
whose only task is to clean cages. It is<br />
too easy to lose control of <strong>the</strong> biofoul<strong>in</strong>g<br />
when <strong>the</strong> clean<strong>in</strong>g crew is assigned<br />
too<strong>the</strong>rseafarmtasks,forassoonas<br />
a net is cleaned biofoul<strong>in</strong>g beg<strong>in</strong>s<br />
aga<strong>in</strong>. Even with <strong>the</strong> more efficient<br />
FIGURE 10<br />
A diver us<strong>in</strong>g a hydraulic net cleaner on a<br />
SeaStation cage <strong>in</strong>stalled at Keahole Po<strong>in</strong>t.<br />
May/June 2010 Volume 44 Number 3 43
net cleaners now on <strong>the</strong> market, it is<br />
reasonable for offshore sea farms to<br />
organize around separate clean<strong>in</strong>g<br />
crews and husbandry crews, for when<br />
<strong>the</strong> conditions are favorable <strong>the</strong> greatest<br />
number of tasks should be accomplished.<br />
For short, wea<strong>the</strong>r w<strong>in</strong>dows<br />
two crews work<strong>in</strong>g on separate but<br />
necessary tasks are better than one.<br />
Communications<br />
When work<strong>in</strong>g with <strong>in</strong>terconnected<br />
submersible cage systems, understand<strong>in</strong>g<br />
often decreases as complexity of<br />
<strong>the</strong> operation <strong>in</strong>creases. There always<br />
comes a po<strong>in</strong>t <strong>in</strong> <strong>the</strong> early part of a<br />
sea farm deployment where <strong>the</strong> owners<br />
believe <strong>the</strong>y fully understand <strong>the</strong><br />
system. Dur<strong>in</strong>g farm management<br />
changes, valuable <strong>in</strong>formation is often<br />
not transferred to new personnel and<br />
is lost.<br />
In some cases, <strong>the</strong> solutions seem so<br />
obvious; it appears <strong>the</strong>re is no need to<br />
consult or relay prior experience or to<br />
be cautious. To illustrate this po<strong>in</strong>t, a<br />
recent example from a different user<br />
group and site is described:<br />
A Flip SeaStation cage was purchased<br />
for an experiment by<br />
some fishery scientists. The<br />
submerged flip cage nearly<br />
identical to <strong>the</strong> one used at<br />
Keahole Po<strong>in</strong>t was <strong>in</strong>stalled at<br />
an offshore site. To identify<br />
<strong>the</strong> location, divers <strong>in</strong>stalled a<br />
small surface buoy connected<br />
to <strong>the</strong> top of <strong>the</strong> spar with a<br />
float<strong>in</strong>g syn<strong>the</strong>tic l<strong>in</strong>e, as specified<br />
by Ocean Spar. Later an<br />
operator replaced this with a<br />
larger buoy connected to <strong>the</strong><br />
spar with cha<strong>in</strong>, obviously<br />
th<strong>in</strong>k<strong>in</strong>g that this was a needed<br />
improvement. Dur<strong>in</strong>g a particularly<br />
large storm generat<strong>in</strong>g<br />
44 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
6 m seas <strong>in</strong> <strong>the</strong> fall of 2007,<br />
<strong>the</strong> SeaStation unexpectedly<br />
sank to a depth of 75 m and rema<strong>in</strong>ed<br />
on bottom with newly<br />
stocked f<strong>in</strong>gerl<strong>in</strong>gs for nearly a<br />
month before it could be raised.<br />
The SeaStation was undamaged,<br />
and <strong>the</strong> majority of <strong>the</strong> f<strong>in</strong>gerl<strong>in</strong>gs<br />
were still alive, though<br />
probably quite hungry. What<br />
happened?<br />
The <strong>in</strong>itial Flip SeaStation cage<br />
was designed symmetrical top<br />
and bottom. Valves are located<br />
on both ends of <strong>the</strong> spar for<br />
convenience to <strong>the</strong> divers dur<strong>in</strong>g<br />
<strong>the</strong> flip maneuver. These valves<br />
are protected by recess<strong>in</strong>g <strong>the</strong>m<br />
<strong>in</strong>to <strong>the</strong> spar buoy. Unlike a<br />
standard SeaStation, an opened<br />
valve would flood <strong>the</strong> central<br />
spar. The center of <strong>the</strong> valve<br />
chamber is opened so a diver<br />
can reach <strong>in</strong> and operate <strong>the</strong><br />
valves as necessary. Dur<strong>in</strong>g <strong>the</strong><br />
storm, <strong>the</strong> surface buoy and<br />
cha<strong>in</strong> substituted by employees<br />
bobbed up and down with <strong>the</strong><br />
waves mak<strong>in</strong>g <strong>the</strong> cha<strong>in</strong> tension<br />
alternate between slack and<br />
taut. When cha<strong>in</strong> is slack it<br />
s<strong>in</strong>ks and hits anyth<strong>in</strong>g not<br />
mov<strong>in</strong>g <strong>in</strong> unison with it.<br />
Highlight<strong>in</strong>g design guidel<strong>in</strong>e<br />
four above “given enough time<br />
<strong>in</strong> <strong>the</strong> ocean a flaw will be<br />
exposed,” a loop of <strong>the</strong> cha<strong>in</strong><br />
found its way <strong>in</strong>to <strong>the</strong> valve<br />
chamber, opened or broke <strong>the</strong><br />
valve, s<strong>in</strong>k<strong>in</strong>g <strong>the</strong> SeaStation.<br />
Experience at Ocean Spar has<br />
shown many times over that<br />
cha<strong>in</strong> connected to a surface<br />
float will damage any submerged<br />
fitt<strong>in</strong>gs it contacts. Notably,<br />
Ocean Spar designs rarely<br />
use cha<strong>in</strong> and rarely specify<br />
cha<strong>in</strong> except <strong>in</strong> unusual circum-<br />
stances. This unfortunate event<br />
tested <strong>the</strong> SeaStation depth rat<strong>in</strong>g,<br />
an unexpected and positive<br />
eng<strong>in</strong>eer<strong>in</strong>g data po<strong>in</strong>t, but unexpectedly<br />
ru<strong>in</strong>ed an expensive<br />
science experiment.<br />
This costly failure, although not<br />
fatal, is an excellent example of how<br />
<strong>the</strong> above design guidel<strong>in</strong>es were determ<strong>in</strong>ed<br />
by “hard won” experience. In<br />
particular, this failure can be attributed<br />
to overlook<strong>in</strong>g design guidel<strong>in</strong>es 1, 4,<br />
6, and 7. It is difficult but necessary to<br />
elim<strong>in</strong>ate this type of failure. The development<br />
of a viable sea farm<strong>in</strong>g <strong>in</strong>dustry<br />
is too slow and difficult to allow small<br />
mistakes like this to h<strong>in</strong>der progress.<br />
Sea farm<strong>in</strong>g is not easy, and novel<br />
ideas on paper or those still <strong>in</strong> ones<br />
head do not transfer to automatic, fulltime,<br />
long-term success <strong>in</strong> <strong>the</strong> ocean.<br />
Pick<strong>in</strong>g Sites<br />
A sea farm must work with<strong>in</strong> <strong>the</strong><br />
restrictions of its permits, but performance<br />
considerations should go <strong>in</strong>to<br />
select<strong>in</strong>g <strong>the</strong> site and its boundaries.<br />
Environmental data usually require<br />
time to accumulate. Unfortunately,<br />
<strong>the</strong> time required for data collection<br />
is <strong>in</strong> direct opposition to <strong>the</strong> need for<br />
quickly generat<strong>in</strong>g revenue from fish<br />
sales. Revenue generation will always<br />
take priority over data collection. If<br />
good long-term data are not available,<br />
<strong>the</strong>n choice of cages with proven durability<br />
reduces needless risk.<br />
Experience shows that <strong>the</strong> permitted<br />
boundaries of offshore sea farms<br />
have almost always been too small to<br />
allow <strong>the</strong> anchor<strong>in</strong>g footpr<strong>in</strong>t required<br />
for operational efficiency. The higher<br />
current areas require a scope ratio of<br />
at least 6:1. Yet high scope ratios are<br />
rarely considered dur<strong>in</strong>g <strong>the</strong> selection<br />
of <strong>the</strong> permit boundaries. The
importance of this can be seen by <strong>the</strong><br />
follow<strong>in</strong>g example:<br />
Assume for <strong>in</strong>stance a site has a<br />
maximum current of 1 m/s and<br />
a cage with 7000 kgf drag is to<br />
be moored <strong>the</strong>re. If <strong>the</strong> permitted<br />
boundaries only allow a 4:1<br />
scope ratio <strong>the</strong>n <strong>the</strong> amount of<br />
buoyancy required to keep <strong>the</strong><br />
cage at depth dur<strong>in</strong>g <strong>the</strong> maximum<br />
current is 1807 kgf. On<br />
<strong>the</strong> o<strong>the</strong>r hand, if <strong>the</strong> moor<strong>in</strong>g<br />
scope ratio is 6:1, <strong>the</strong> amount<br />
of buoyancy required becomes<br />
1183 kgf. The required buoyancy<br />
is reduced by a factor of<br />
0.66 when us<strong>in</strong>g <strong>the</strong> 6/1<br />
scope ratio. This fact <strong>in</strong>creases<br />
<strong>the</strong> eng<strong>in</strong>eer<strong>in</strong>g flexibility for<br />
any sea farm design.<br />
It is <strong>in</strong> <strong>the</strong> farm owners’ <strong>in</strong>terest<br />
to advocate for a site that allows at<br />
least a 6:1 scope ratio for <strong>the</strong> moor<strong>in</strong>g<br />
system.<br />
Although fixed by <strong>the</strong> permit<br />
boundaries and unavailable as an alternative,<br />
<strong>the</strong> use of larger scope ratios<br />
at Keahole Po<strong>in</strong>t would also have reduced<br />
if not elim<strong>in</strong>ated <strong>the</strong> stability<br />
problems encountered <strong>the</strong>re. The effectiveness<br />
of <strong>the</strong> fixed buoyancy <strong>in</strong>herent<br />
<strong>in</strong> each SeaStation cage would<br />
have been <strong>in</strong>creased by a factor of<br />
1.50.<br />
Conclusions<br />
The use of <strong>the</strong> SeaStation cages<br />
at Keahole Po<strong>in</strong>t is ano<strong>the</strong>r example<br />
of <strong>the</strong>ir ability to survive and function<br />
<strong>in</strong> offshore conditions. Arguably, <strong>the</strong><br />
idea of keep<strong>in</strong>g it simple favors <strong>in</strong>dividually<br />
moored cages ra<strong>the</strong>r than coupled<br />
grid moor<strong>in</strong>gs. Importantly, valuable<br />
and efficient operations and features<br />
were developed at <strong>the</strong> Keahole Po<strong>in</strong>t<br />
sea farm. In particular, <strong>the</strong> float<strong>in</strong>g and<br />
flip characteristics prototyped at <strong>the</strong> site<br />
proved workable and promises even<br />
greater benefits as <strong>the</strong>se features undergo<br />
fur<strong>the</strong>r development and become better<br />
understood with greater use.<br />
Look<strong>in</strong>g <strong>in</strong>to <strong>the</strong> future, <strong>the</strong> ability<br />
to raise a cage to <strong>the</strong> surface so that<br />
volume is reduced by half has implications<br />
for yet untried harvest techniques,<br />
all of which require some<br />
means of first concentrat<strong>in</strong>g fish before<br />
<strong>the</strong>ir removal from <strong>the</strong> cage. In particular,<br />
any new active net harvest techniques<br />
will be easier because of this<br />
ability. The successful technique of<br />
rais<strong>in</strong>g <strong>the</strong> bottom of <strong>the</strong> net to concentrate<br />
<strong>the</strong> fish may be even more effective<br />
after <strong>the</strong> cage volume is already<br />
reduced by one half (Loverich et al.,<br />
1996).<br />
Dur<strong>in</strong>g a passive harvest, <strong>the</strong> fish<br />
move <strong>in</strong>to <strong>the</strong> harvest area by choice<br />
ra<strong>the</strong>r than by force. In 1996, Ocean<br />
Spar personnel achieved a passive<br />
harvest of 2500 salmon stocked <strong>in</strong><br />
<strong>the</strong> orig<strong>in</strong>al 2600-m 3 SeaStation cage.<br />
The development of o<strong>the</strong>r novel passive<br />
harvest techniques will be encouraged<br />
by a cage that can be easily<br />
reduced to half volume. Ideas for passive<br />
techniques will evolve as use of<br />
<strong>the</strong> SeaStation cage cont<strong>in</strong>ues and as<br />
<strong>in</strong>formation is spread through <strong>the</strong><br />
<strong>in</strong>dustry.<br />
The Flip capability of SeaStation<br />
has potential for harvest by section<strong>in</strong>g<br />
off a portion of <strong>the</strong> cage and <strong>the</strong>n flipp<strong>in</strong>g<br />
it to capture fish <strong>in</strong> that special<br />
section. More efficient clean<strong>in</strong>g strategies<br />
and equipment can also develop<br />
around <strong>the</strong> flip tactic. Some sea farms<br />
require that <strong>the</strong> farmed fish be treated<br />
by a technique called tarp<strong>in</strong>g to rid<br />
<strong>the</strong>m of parasites. A tarp, <strong>in</strong>stalled by<br />
divers, surrounds <strong>the</strong> net, creat<strong>in</strong>g a<br />
closed pool of water <strong>in</strong>to which treatments<br />
are adm<strong>in</strong>istered. Install<strong>in</strong>g <strong>the</strong><br />
tarp is difficult <strong>in</strong> <strong>the</strong> ocean. With a<br />
flip cage, it is easy to imag<strong>in</strong>e but yet<br />
to be proven that <strong>the</strong> tarp can be <strong>in</strong>stalled<br />
on <strong>the</strong> top of <strong>the</strong> cage when<br />
<strong>the</strong> cage is submerged or surfaced.<br />
When<strong>the</strong>cageisflipped and <strong>the</strong>n<br />
surfaced, <strong>the</strong> tarp ends up on <strong>the</strong><br />
cage bottom ready for <strong>the</strong> treatment<br />
process.<br />
The <strong>in</strong>itial use of <strong>the</strong> SeaStation cage<br />
at Keahole Po<strong>in</strong>t proved <strong>the</strong> effectiveness<br />
of several <strong>in</strong>novative designs and<br />
approaches to important operational<br />
issues <strong>in</strong>herent <strong>in</strong> offshore fish farm<strong>in</strong>g.<br />
The results provide an excellent<br />
foundation for future development<br />
of additional operational techniques<br />
and SeaStation features. As <strong>the</strong> Keahole<br />
Po<strong>in</strong>t sea farm cont<strong>in</strong>ues under new<br />
ownership, <strong>the</strong> opportunities for fur<strong>the</strong>r<br />
ref<strong>in</strong>ement of techniques and design<br />
rema<strong>in</strong> numerous and promis<strong>in</strong>g.<br />
References<br />
Baldw<strong>in</strong>, K., Celikkol, B., Steen, R.,<br />
Michel<strong>in</strong>, D., Muller, E., Lavoie, P. 2000.<br />
Open ocean aquaculture eng<strong>in</strong>eer<strong>in</strong>g:<br />
Moor<strong>in</strong>g & net pen deployment. <strong>Mar<strong>in</strong>e</strong><br />
Technol Soc J 34(1):53-58.<br />
Benetti, D., Brand, L., Coll<strong>in</strong>, J., Orhun, R.,<br />
Benetti, A., O’Hanlon, B., Danylchuk, A.,<br />
Alston, D., Rivera, J., Carbarcas, A. 2006.<br />
Can aquaculture of carnivorous fish be susta<strong>in</strong>able:<br />
Case studies from <strong>the</strong> Caribbean.<br />
World Aquac, 37(1):44-47.<br />
Berteaux, H.O. 1991. Coastal and oceanic<br />
buoy eng<strong>in</strong>eer<strong>in</strong>g. Woods Hole, MA: H.O.<br />
Berteaux, pp. 79-102.<br />
Chambers, M., Howell, W.H. 2005. Prelim<strong>in</strong>ary<br />
<strong>in</strong>formation on cod and haddock<br />
production <strong>in</strong> submerged cages off <strong>the</strong> coast<br />
of New Hampshire, USA. ICES J Mar Sci,<br />
63:385-392.<br />
Loverich, G., Forster, J. 2000. Advances <strong>in</strong><br />
offshore cage design us<strong>in</strong>g spar buoys. <strong>Mar<strong>in</strong>e</strong><br />
Technol Soc J 34(1):18-28.<br />
May/June 2010 Volume 44 Number 3 45
Loverich, G.F., Swanson, K., Gace, L. 1996.<br />
Offshore aquaculture harvest and transport<br />
concept; feasibility and development.<br />
In: NOAA Grant Award No. NA56FD0071.<br />
pp. 22-23.<br />
Loverich, G.F., Swanson, K.T. 1993. Offshore<br />
sea farms: 25 Months of experience.<br />
In: Fish farm<strong>in</strong>g technology: Proceed<strong>in</strong>gs of<br />
<strong>the</strong> First International Conference on Fish<br />
Farm<strong>in</strong>g Technology. pp. 241-249. Trondheim,<br />
Norway.<br />
Perez, O.M., Ross, L.G., Telfer, T.C. 2003.<br />
On <strong>the</strong> calculation of wave climate for offshore<br />
cage culture site selection: A case study<br />
<strong>in</strong> Tenerife (Canary Islands). Aquac Eng<br />
29:1-21.<br />
Pittenger, R., Anderson, B., Benetti, D.,<br />
Dayton, P., Dewey, B., Goldburg, R.,<br />
Rieser, A., Sher, B., and Sturgulewski, A. 2007.<br />
<strong>Susta<strong>in</strong>able</strong> mar<strong>in</strong>e aquaculture: Fulfill<strong>in</strong>g <strong>the</strong><br />
promise; manag<strong>in</strong>g <strong>the</strong> risks. Report of <strong>the</strong><br />
<strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong> Task Force.<br />
Rocheleau, R. 1979. Evaluation of extreme<br />
w<strong>in</strong>d and wave climate at Keahole Po<strong>in</strong>t,<br />
Hawaii. Work<strong>in</strong>g Paper No. 42. Sea Grant<br />
College Program, University of Hawaii.<br />
46 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal
PAPER<br />
Technology Needs for Improved Operational<br />
Efficiency of Open Ocean Cage Culture<br />
AUTHOR<br />
Richard Langan<br />
Atlantic <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong> Center,<br />
University of New Hampshire<br />
The Need for Technological<br />
Innovation for Offshore<br />
Farm<strong>in</strong>g Systems<br />
Farm<strong>in</strong>g <strong>in</strong> offshore mar<strong>in</strong>e waters<br />
has been identified as a potential<br />
option for <strong>in</strong>creased aquaculture production,<br />
and <strong>the</strong>re has been global<br />
<strong>in</strong>terest <strong>in</strong> <strong>the</strong> development of this sector<br />
for more than two decades (Ryan,<br />
2004). There is sufficient rationale for<br />
pursu<strong>in</strong>g <strong>the</strong> development of open<br />
ocean farm<strong>in</strong>g. Favorable features of<br />
open ocean waters, which <strong>in</strong>clude<br />
ample space, tremendous carry capacity,<br />
<strong>the</strong> potential to reduce some of<br />
<strong>the</strong> negative environmental impacts<br />
of coastal fish farm<strong>in</strong>g (Ryan, 2004;<br />
Helsley and Kim, 2005; Ward et al.,<br />
2006), and optimal environmental<br />
conditions for a wide variety of mar<strong>in</strong>e<br />
species (Ostrowski and Helsley,<br />
2003; Ryan, 2004; Benetti et al.,<br />
2006; Howell et al., 2006), have encouraged<br />
many countries to engage <strong>in</strong><br />
offshore development. However,<br />
w<strong>in</strong>d and wave conditions <strong>in</strong> most<br />
of <strong>the</strong> world’s oceans pose significant<br />
technical and operational challenges.<br />
Initial attempts at offshore farm<strong>in</strong>g<br />
consisted of mov<strong>in</strong>g surface cages to<br />
<strong>in</strong>creas<strong>in</strong>gly exposed locations and<br />
relied to a large extent on trial and<br />
error. As a result, many structural failures<br />
occurred. Farm operators were<br />
ABSTRACT<br />
Advances <strong>in</strong> eng<strong>in</strong>eer<strong>in</strong>g design and construction of moor<strong>in</strong>g and conta<strong>in</strong>ment<br />
systems capable of withstand<strong>in</strong>g forces of waves and currents <strong>in</strong> open ocean environments<br />
over <strong>the</strong> past two decades have brought open sea fish farm<strong>in</strong>g much<br />
closer to realization. Despite <strong>the</strong> progress <strong>in</strong> development of moor<strong>in</strong>g and cage technologies,<br />
expansion of farm<strong>in</strong>g <strong>in</strong> offshore waters has been measured, primarily due<br />
to <strong>the</strong> <strong>in</strong>herent difficulties of operat<strong>in</strong>g <strong>in</strong> an environment that is frequently <strong>in</strong>accessible<br />
by vessels and farm personnel due to hostile wea<strong>the</strong>r conditions. In order for<br />
open ocean farm<strong>in</strong>g to achieve large-scale production, eng<strong>in</strong>eered systems that are<br />
capable of autonomous operation for periods rang<strong>in</strong>g from days to weeks are needed.<br />
Some advances <strong>in</strong> <strong>the</strong> development of support<strong>in</strong>g technologies have been made;<br />
however, until we see off-<strong>the</strong>-shelf technologies for remote operation of rout<strong>in</strong>e<br />
tasks such as feed<strong>in</strong>g, ma<strong>in</strong>tenance, and observation of stock and environmental<br />
conditions, development will likely be limited <strong>in</strong> scope and spatial scale.<br />
forced to spend more time repair<strong>in</strong>g<br />
damage than tend<strong>in</strong>g to livestock, impact<strong>in</strong>g<br />
production schedules and profit<br />
marg<strong>in</strong>s (Ryan, 2004). Beg<strong>in</strong>n<strong>in</strong>g <strong>in</strong><br />
<strong>the</strong> early 1990s, several groups began<br />
to apply a more sophisticated eng<strong>in</strong>eer<strong>in</strong>g<br />
approach to cage (Lisac, 1996;<br />
Loverich and Goudey, 1996) and<br />
moor<strong>in</strong>g design (Fredriksson et al.,<br />
2004); assessment of <strong>the</strong> structural<br />
<strong>in</strong>tegrity of cage materials (DeCew<br />
et al., 2005); and model<strong>in</strong>g <strong>the</strong> effects<br />
of hydrodynamic forc<strong>in</strong>g on cages<br />
and nett<strong>in</strong>g (Lader and Fredheim,<br />
2003; Swift et al., 2005). This approach<br />
led to improvements <strong>in</strong> design,<br />
materials selection, and <strong>in</strong>tegrity<br />
of offshore systems, reduc<strong>in</strong>g <strong>the</strong> possibility<br />
of system failure (Fredriksson<br />
et al., 2003).<br />
In recent years, more robust versions<br />
of gravity cage technologies<br />
have been successfully deployed <strong>in</strong><br />
some exposed sites (Ryan, 2004), and<br />
some submersible cage technologies<br />
have a proven performance record <strong>in</strong><br />
very exposed locations (Chambers<br />
et al., 2007); however, secure conta<strong>in</strong>ment<br />
is but one aspect of <strong>the</strong> technology<br />
needed for large-scale offshore<br />
farm<strong>in</strong>g. In addition, <strong>the</strong>re are challenges<br />
for nearly all aspects of dayto-day<br />
farm operation (Browdy and<br />
Hargreaves, 2009). Methods and<br />
equipment developed for rout<strong>in</strong>e operations<br />
such as feed<strong>in</strong>g, harvest<strong>in</strong>g,<br />
and monitor<strong>in</strong>g livestock and environmental<br />
conditions at protected <strong>in</strong>shore<br />
sites have been designed for calm sea<br />
conditions and for <strong>the</strong> most part cannot<br />
be directly transferred for use <strong>in</strong><br />
<strong>the</strong> offshore environment. Development<br />
of proven operational systems<br />
appropriate for open ocean environments<br />
has not kept pace with cage<br />
development. Until we see fully <strong>in</strong>tegrated<br />
farm<strong>in</strong>g systems that are essentially<br />
capable of autonomous operation<br />
for a period of days or perhaps weeks,<br />
growth of <strong>the</strong> offshore sector will likely<br />
May/June 2010 Volume 44 Number 3 47
e limited (Browdy and Hargreaves,<br />
2009).<br />
Improv<strong>in</strong>g Operational<br />
Efficiencies<br />
The operational challenges for offshore<br />
farm<strong>in</strong>g can potentially be overcome<br />
through <strong>the</strong> development of new<br />
technologies or adapatation of technologies<br />
that are used for farm<strong>in</strong>g <strong>in</strong> neashore<br />
environments, or perhaps from<br />
o<strong>the</strong>r <strong>in</strong>dustry and technology sectors<br />
altoge<strong>the</strong>r. The ultimate goal of<br />
automation is to reduce <strong>the</strong> need for<br />
daily visits to remote farm sites by service<br />
vessels and personnel, reduce <strong>the</strong><br />
need for divers to perform rout<strong>in</strong>e<br />
ma<strong>in</strong>tenance and observation, and improve<br />
operational efficiencies. Reduc<strong>in</strong>g<br />
cost, improv<strong>in</strong>g safety for farm<br />
workers, and maximiz<strong>in</strong>g production<br />
efficiencies can be achieved through<br />
automation of many rout<strong>in</strong>e farm operations.<br />
Address<strong>in</strong>g each of <strong>the</strong> operational<br />
areas is important; however, <strong>in</strong>tegration<br />
of <strong>the</strong> technology solutions <strong>in</strong>to “<strong>in</strong>telligent”<br />
fully automated farm<strong>in</strong>g systems<br />
that are commercially available to producers<br />
should be <strong>the</strong> ultimate longterm<br />
goal for open ocean farm<strong>in</strong>g.<br />
Feed<strong>in</strong>g Systems<br />
Of all mar<strong>in</strong>e fish farm<strong>in</strong>g operations,<br />
feed<strong>in</strong>g is <strong>the</strong> most important.<br />
Feed<strong>in</strong>g fish <strong>the</strong> correct diet, <strong>in</strong> <strong>the</strong><br />
right amounts and at proper <strong>in</strong>tervals,<br />
is critical to fish growth and health,<br />
and <strong>in</strong> turn to <strong>the</strong> profitability of <strong>the</strong><br />
farm<strong>in</strong>g enterprise. Near-shore approaches,<br />
which <strong>in</strong>clude dispens<strong>in</strong>g<br />
feed by cannons from a service vessel<br />
or automated feed<strong>in</strong>g with blowers<br />
mounted on centralized feed barges,<br />
are severely hampered by rough seas.<br />
An ideal feed<strong>in</strong>g system for offshore<br />
aquaculture would be robust, remotely<br />
controlled, fully automated, able to<br />
48 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
accommodate <strong>the</strong> volume of food<br />
needed for a two- to three-week period,<br />
and possessed of a hydraulic ra<strong>the</strong>r<br />
than a pneumatic feed delivery system.<br />
It would also ideally be capable of<br />
wireless transmission of <strong>in</strong>-cage video,<br />
environmental monitor<strong>in</strong>g data, or<br />
o<strong>the</strong>r <strong>in</strong>formation critical to farm operation<br />
(Browdy and Hargreaves, 2009).<br />
Although no system as described currently<br />
exists, some progress has been<br />
made. The Scottish company Gael<br />
Force has developed <strong>the</strong> Sea Cap, a<br />
concrete feed barge that has operated<br />
successfully <strong>in</strong> exposed locations for<br />
several years. In current models, feed<br />
is delivered pneumatically, although<br />
<strong>the</strong> company has plans to develop<br />
water-borne feed delivery system.<br />
The University of New Hampshire<br />
(UNH), which operates an experimental<br />
offshore farm <strong>in</strong> <strong>the</strong> Northwest Atlantic,<br />
has developed two small (s<strong>in</strong>gle<br />
cage), remotely operated feeders that<br />
have been <strong>in</strong> use s<strong>in</strong>ce 2001 (Rice<br />
et al., 2003), and deployed a multicage<br />
larger feeder <strong>in</strong> 2007 (Figure 1).<br />
Developed <strong>in</strong> conjunction with<br />
Ocean Spar and <strong>the</strong> <strong>Aquaculture</strong> Eng<strong>in</strong>eer<strong>in</strong>g<br />
Group (AEG), <strong>the</strong> feeder has<br />
four separate feed silos and can dis-<br />
FIGURE 1<br />
A photo of <strong>the</strong> 20-ton capacity multi-cage<br />
feeder developed by <strong>the</strong> University of New<br />
Hampshire (UNH), Ocean Spar, and <strong>the</strong> <strong>Aquaculture</strong><br />
Eng<strong>in</strong>eer<strong>in</strong>g Group moored at UNH’s<br />
experimental offshore farm<strong>in</strong>g site <strong>in</strong> <strong>the</strong><br />
Northwest Atlantic.<br />
pense feed to four submerged cages<br />
(Turmelle et al., 2006, Celikkol and<br />
Langan, 2007). It also <strong>in</strong>corporates a<br />
two-way remotely operated communications<br />
system that controls <strong>the</strong> tim<strong>in</strong>g<br />
and amount of feed delivery and can<br />
transmit video from <strong>in</strong>-cage cameras<br />
to monitor fish behavior and response<br />
to feed <strong>in</strong>troduction. The system also<br />
houses a unique acoustic track<strong>in</strong>g system<br />
that can cont<strong>in</strong>uously monitor <strong>the</strong><br />
behavior and physiology of tagged fish<br />
for up to 40 days (Howell et al., 2006;<br />
Rillahan et al., 2009).<br />
The AEG has also <strong>in</strong>dependently<br />
developed ano<strong>the</strong>r automated feeder<br />
capable of water-borne delivery of<br />
feed to multiple submerged or surface<br />
cages (Figure 2). One of <strong>the</strong> AEG feeders<br />
is <strong>in</strong> operation at a salmon farm<strong>in</strong>g<br />
site <strong>in</strong> <strong>the</strong> Bay of Fundy and ano<strong>the</strong>r is<br />
scheduled for deployment <strong>in</strong> Newfoundland.<br />
Hukilau Foods, which operates<br />
an offshore Pacific threadf<strong>in</strong><br />
farm off Oahu, HI, has also developed<br />
a remotely operated multi-cage hydraulic<br />
feeder (Figure 3). The feed delivery<br />
unit is mounted on a barge that<br />
is moored at <strong>the</strong> company’s cagesite<br />
and can dispense feed to as many as<br />
12 submerged cages. Ocean Spar<br />
from Ba<strong>in</strong>bridge, WA, is develop<strong>in</strong>g<br />
<strong>the</strong> SeaSpar, a semi-submerged feeder<br />
designed to operate <strong>in</strong> Category 3<br />
FIGURE 2<br />
<strong>Aquaculture</strong> Eng<strong>in</strong>eer<strong>in</strong>g Group’s 100-ton capacity<br />
multi-cage feeder moored at a salmon<br />
farm<strong>in</strong>g site <strong>in</strong> <strong>the</strong> Bay of Fundy, Canada.
FIGURE 3<br />
The 20-ton capacity multi-cage feeder developed<br />
by Hukilau Foods moored at <strong>the</strong>ir offshore<br />
submerged cage site off Oahu, HI.<br />
hurricane conditions and to withstand<br />
Category 5 hurricane events. SeaSpars<br />
are currently designed to hold up to<br />
100 MT feed, and larger capacity systems<br />
are <strong>in</strong> <strong>the</strong> plann<strong>in</strong>g stage (Ocean<br />
Spar, 2010).<br />
Some cage technology companies,<br />
such as Farm Ocean and SADCO,<br />
have <strong>in</strong>tegrated feed<strong>in</strong>g systems <strong>in</strong>to<br />
<strong>the</strong>ir cage designs (Ryan, 2004); however,<br />
both systems have experienced<br />
operational difficulties. With <strong>the</strong> exception<br />
of systems from AEG and<br />
Gale Force, none of <strong>the</strong> previously<br />
mentioned automated on-site feed systems<br />
developed for offshore applications<br />
are commercially available.<br />
Future considerations for automated<br />
feed systems should also <strong>in</strong>clude mobile<br />
feed vessels that can connect to submerged<br />
feed distribution systems similar<br />
to <strong>the</strong> way LNG tankers connect to<br />
offshore fuel distribution term<strong>in</strong>als.<br />
Theadvantagesofmobilefeeders<strong>in</strong>clude<br />
<strong>the</strong> ability to move <strong>the</strong> vessel<br />
to a protected location dur<strong>in</strong>g severe<br />
storms and to transit to port for refuel<strong>in</strong>g<br />
and restock<strong>in</strong>g feed supplies,<br />
thus avoid<strong>in</strong>g at-sea fuel and feed<br />
transfers that can be severely hampered<br />
by sea conditions.<br />
Biofoul<strong>in</strong>g Control<br />
Biofoul<strong>in</strong>g <strong>in</strong>creases weight and<br />
drag on cage and moor<strong>in</strong>g systems<br />
and reduces <strong>the</strong> flow of oxygenated<br />
water through <strong>the</strong> conta<strong>in</strong>ment volume.<br />
In addition, biofoul<strong>in</strong>g communities<br />
may harbor parasites and<br />
disease-caus<strong>in</strong>g organisms that can affect<br />
fish health (Braithwaite et al., 2007).<br />
There are essentially two approaches<br />
to biofoul<strong>in</strong>g management—removal<br />
or prevention. Current methods of<br />
biofoul<strong>in</strong>g removal require divers, a<br />
practice that is both costly and dangerous,<br />
particularly when servic<strong>in</strong>g deepwater<br />
submerged cages. Chang<strong>in</strong>g<br />
nets dur<strong>in</strong>g production cycles, ano<strong>the</strong>r<br />
common practice at near-shore farm<br />
sites, is also labor <strong>in</strong>tensive, creates <strong>in</strong>creased<br />
risk of escapement, and is impractical<br />
for most submerged cage<br />
designs. There have been several alternative<br />
approaches to biofoul<strong>in</strong>g management<br />
<strong>in</strong> recent years. Ocean Spar<br />
developed <strong>the</strong> extended spar version<br />
of <strong>the</strong> SeaStation cage. The additional<br />
length of <strong>the</strong> central spar provides sufficient<br />
buoyancy when filled with air to<br />
allow nearly half of <strong>the</strong> cage nett<strong>in</strong>g to<br />
be exposed (Figure 4). The comb<strong>in</strong>ation<br />
of air-dry<strong>in</strong>g to kill foul<strong>in</strong>g organisms<br />
and accessibility of half <strong>the</strong> cage<br />
nett<strong>in</strong>g for clean<strong>in</strong>g from a service vessel<br />
elim<strong>in</strong>ates <strong>the</strong> need for divers. Ano<strong>the</strong>r<br />
<strong>in</strong>novation by Ocean Spar was a<br />
change to <strong>the</strong> moor<strong>in</strong>g system that al-<br />
FIGURE 4<br />
OceanSpar’s extended spar SeaStation ® cage<br />
<strong>in</strong> <strong>the</strong> fully raised position.<br />
lowed operators to “flip” a SeaStation,<br />
so that ei<strong>the</strong>r <strong>the</strong> upper or lower half of<br />
<strong>the</strong> cage nett<strong>in</strong>g could be exposed and<br />
cleaned at <strong>the</strong> surface. Similarly, <strong>the</strong><br />
AquaPod submersible cage from<br />
Ocean Farm Technologies (Ma<strong>in</strong>e) is<br />
sufficiently buoyant that nearly half<br />
<strong>the</strong> cage can be exposed above <strong>the</strong><br />
water’s surface. The cage can be easily<br />
rotated and <strong>the</strong> exposed surfaces can be<br />
cleaned from a service vessel.<br />
Robotic, subsurface net cleaners<br />
that use high-pressure water jets or<br />
brushes and can be operated from a<br />
service vessel have been proposed as<br />
an alternative to SCUBA div<strong>in</strong>g.<br />
There have been a number of designs<br />
created and prototypes have been developed,<br />
although very few have actually<br />
become commercially available.<br />
One system that is currently on <strong>the</strong><br />
market is <strong>the</strong> Yanmar NCL SE-3<br />
(www.yanmar.com.au/); however, it<br />
is unclear how extensively this or<br />
o<strong>the</strong>r robotic cleaners are used <strong>in</strong> commercial<br />
farm<strong>in</strong>g operations.<br />
As previously mentioned, <strong>the</strong> alternative<br />
to clean<strong>in</strong>g is prevent<strong>in</strong>g <strong>the</strong><br />
settlement of organisms. Current metalbased<br />
(e.g., copper) antifoul<strong>in</strong>g coat<strong>in</strong>gs,<br />
although widely used, are now<br />
considered less desirable for aquaculture<br />
because of possible adverse environmental<br />
effects and consumer<br />
concerns that may jeopardize market<br />
image. There has been a great deal of<br />
research on <strong>the</strong> development non-toxic<br />
antifoul<strong>in</strong>g coat<strong>in</strong>gs, ma<strong>in</strong>ly fulfill<strong>in</strong>g<br />
<strong>the</strong> needs of <strong>the</strong> shipp<strong>in</strong>g <strong>in</strong>dustry<br />
with far less consideration of <strong>the</strong><br />
needs and issues related to aquaculture<br />
(Maréchal and Hellio, 2009).<br />
Some success has been achieved with<br />
silicone-based coat<strong>in</strong>gs; however, <strong>the</strong>y<br />
are difficult to apply to nett<strong>in</strong>g materials<br />
and have primarily been used<br />
for vessel hull application. In recent<br />
years, several commercial companies<br />
May/June 2010 Volume 44 Number 3 49
and research efforts have specifically<br />
targeted <strong>the</strong> aquaculture <strong>in</strong>dustry. Research<br />
conducted by <strong>the</strong> Australian<br />
<strong>Aquaculture</strong> Cooperative Research<br />
Centre has focused on antifoul<strong>in</strong>g<br />
agents belong<strong>in</strong>g to <strong>the</strong> families of isothiazolones,<br />
furanones, or comb<strong>in</strong>ations<br />
<strong>the</strong>reof that have been found to<br />
be effective (Raveendram and Limna<br />
Mol, 2009). This <strong>in</strong>vention consists<br />
of an antifoul<strong>in</strong>g polymer compris<strong>in</strong>g<br />
an isothiazolone or one or more<br />
furanone antifoul<strong>in</strong>g agents and is capable<br />
of ma<strong>in</strong>ta<strong>in</strong><strong>in</strong>g broad-spectrum<br />
antifoul<strong>in</strong>g activity for an extended<br />
period. The polymer can be <strong>in</strong>corporated<br />
<strong>in</strong>to a coat<strong>in</strong>g, such as <strong>in</strong> <strong>the</strong><br />
product Netsafe available from Wattyl<br />
Ltd. <strong>in</strong> Australia, or used to form a<br />
fiber, which may <strong>the</strong>n be <strong>in</strong>corporated<br />
as part of <strong>the</strong> thread structure of a<br />
multi-stranded nett<strong>in</strong>g material. A material<br />
us<strong>in</strong>g this technology, Thorn-D,<br />
produced by <strong>the</strong> Micanti Corporation<br />
<strong>in</strong> <strong>the</strong> Ne<strong>the</strong>rlands, is now commercially<br />
available.<br />
Pittsburgh Plate Glass, Inc., a United<br />
States producer of coat<strong>in</strong>gs for a wide<br />
variety of <strong>in</strong>dustrial uses, has developed<br />
several antifoul<strong>in</strong>g coat<strong>in</strong>gs for<br />
aquaculture applications. BUOY<br />
COAT is a self-polish<strong>in</strong>g protective<br />
coat<strong>in</strong>g that conta<strong>in</strong>s no copper or<br />
co-biocides but relies on a non-toxic<br />
mode of action to prevent unwanted<br />
mar<strong>in</strong>e growth. BUOY COAT PLUS<br />
is identical to BUOY COAT and<br />
conta<strong>in</strong>s an algaecide, Z<strong>in</strong>c Omad<strong>in</strong>e.<br />
VR-1 is a v<strong>in</strong>yl ros<strong>in</strong>-based ablative<br />
coat<strong>in</strong>g for use on nett<strong>in</strong>g. These<br />
three coat<strong>in</strong>gs are currently be<strong>in</strong>g tested<br />
on a variety of nett<strong>in</strong>g materials by <strong>the</strong><br />
researchers at <strong>the</strong> UNH.<br />
Researchers <strong>in</strong> Taiwan have developed<br />
a coat<strong>in</strong>g consist<strong>in</strong>g of polyurethane<br />
res<strong>in</strong> with carbon black and<br />
graphite, which generates free chlor<strong>in</strong>e<br />
at <strong>the</strong> coat<strong>in</strong>g surface. A 500-day field<br />
50 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
test showed that <strong>the</strong> coat<strong>in</strong>g reduced<br />
mar<strong>in</strong>e biofoul<strong>in</strong>g by approximately<br />
79%, and <strong>the</strong> chlor<strong>in</strong>e produced was<br />
with<strong>in</strong> safe levels, and judged not to<br />
pollute <strong>the</strong> sea. Problems with <strong>the</strong> durability<br />
of <strong>the</strong> coat<strong>in</strong>g require additional<br />
development (Huang et al., 2010).<br />
There has been some experience<br />
with <strong>the</strong> use of nets made of copper alloys<br />
(e.g., bronze, brass) <strong>in</strong> Japan and<br />
Australia, and more recently <strong>in</strong> Panama,<br />
Chile, Ch<strong>in</strong>a, and <strong>the</strong> United States, and<br />
<strong>the</strong>re is evidence that <strong>the</strong> materials are<br />
effective <strong>in</strong> resist<strong>in</strong>g foul<strong>in</strong>g (Figure 5).<br />
An additional advantage of <strong>the</strong> metal<br />
alloys is <strong>the</strong> greater resistance to<br />
breaches from predators, boats, and<br />
equipment, thus reduc<strong>in</strong>g <strong>the</strong> possibility<br />
of escapement. O<strong>the</strong>r factors such<br />
as cost, <strong>in</strong>stallation difficulties due to<br />
weight,methodofattachmentto<br />
cage frames, <strong>in</strong>compatibilities with<br />
o<strong>the</strong>r metal components, as well as environmental<br />
risks must be addressed<br />
before metal alloys become widely<br />
adopted.<br />
Even if <strong>the</strong> research on new improved<br />
antifoul<strong>in</strong>g solutions is very active,<br />
<strong>the</strong> perfect solution has yet to be<br />
found. The most promis<strong>in</strong>g areas of<br />
FIGURE 5<br />
A small offshore cage with a copper alloy nett<strong>in</strong>g<br />
after a 120-day deployment at <strong>the</strong> University<br />
of New Hampshire’s experimental offshore<br />
site. Note <strong>the</strong> hydroid and mussel foul<strong>in</strong>g on<br />
l<strong>in</strong>es and cage frame and <strong>the</strong> absence of any<br />
settlement on <strong>the</strong> nett<strong>in</strong>g material.<br />
development are <strong>the</strong> production of<br />
bioactive substances from mar<strong>in</strong>e organisms,<br />
which could be formulated<br />
with<strong>in</strong> pa<strong>in</strong>t matrix and <strong>the</strong> creation<br />
of new materials that cannot foul.<br />
However, <strong>in</strong> order to develop better<br />
solutions, a greater understand<strong>in</strong>g of<br />
<strong>the</strong> strategies of foul<strong>in</strong>g organisms as<br />
well as on <strong>the</strong> <strong>in</strong>terspecies relationships<br />
<strong>in</strong> benthic communities is needed<br />
(Maréchal and Hellio, 2009).<br />
Grad<strong>in</strong>g and Harvest<strong>in</strong>g<br />
In-cage grad<strong>in</strong>g dur<strong>in</strong>g a production<br />
cycle to ma<strong>in</strong>ta<strong>in</strong> more uniform<br />
fish size is a difficult operation for surface<br />
cages <strong>in</strong> near-shore environments<br />
and has proven to be even more daunt<strong>in</strong>g<br />
for open ocean submerged cages<br />
(OATP, 2007; Browdy and Hargreaves,<br />
2009). For many mar<strong>in</strong>e species, establishment<br />
of broodstock l<strong>in</strong>es that will<br />
yield offspr<strong>in</strong>g with more uniform<br />
growth rates is at a very early stage of<br />
development. Therefore, grad<strong>in</strong>g is<br />
even more critical for <strong>the</strong>se relatively<br />
new species than for species with<br />
well-established broodstock l<strong>in</strong>es such<br />
as Atlantic salmon (Howell et al.,<br />
2006). Greater knowledge of behavioral<br />
responses of fish to visual or auditory<br />
stimuli may be very useful <strong>in</strong><br />
develop<strong>in</strong>g automated systems for <strong>in</strong>cage<br />
grad<strong>in</strong>g (Rillahan et al., 2009).<br />
Harvest<strong>in</strong>g, and particularly partial<br />
cage harvest<strong>in</strong>g of physoclistous<br />
species (e.g., Atlantic cod) grown at<br />
depth, has presented some difficulties<br />
due to <strong>in</strong>flation of <strong>the</strong> swim bladder<br />
as <strong>the</strong> fish are brought to <strong>the</strong> surface<br />
(Howell et al., 2006). For virtually all<br />
offshore farms, harvest<strong>in</strong>g <strong>in</strong>volves a<br />
great deal of div<strong>in</strong>g, result<strong>in</strong>g <strong>in</strong> <strong>in</strong>creased<br />
cost and risk to personnel<br />
(Fredheim and Langan, 2009). Traditional<br />
methods, such as crowd<strong>in</strong>g and<br />
pump<strong>in</strong>g, are stressful for <strong>the</strong> fish,
which may affect flesh quality. These<br />
methods also require calm sea conditions<br />
and <strong>in</strong>-cage divers (Chambers<br />
et al., 2007). The use of small harvest<br />
cages attached by a tunnel to <strong>the</strong> ma<strong>in</strong><br />
cage has also been tried, but that technique<br />
also requires a considerable<br />
amountof<strong>in</strong>-cagedivetimetodrive<br />
fish toward <strong>the</strong> tunnel (Chambers<br />
et al., 2007). As with <strong>in</strong>-cage grad<strong>in</strong>g,<br />
knowledge of fish response to visual or<br />
auditory stimuli may be useful <strong>in</strong> tra<strong>in</strong><strong>in</strong>g<br />
fish to “self-harvest” (Rillahan<br />
et al., 2009).<br />
On-site Power Generation<br />
Powerrequirementsforfarm<strong>in</strong>g<br />
equipment such as feeders, lights,<br />
pumps, <strong>in</strong>struments, and communications<br />
equipment can be large. The<br />
most commonly used source of electrical<br />
and hydraulic power for farm<strong>in</strong>g<br />
equipment is diesel eng<strong>in</strong>es mounted<br />
on vessels, barges, and <strong>in</strong> some cases,<br />
on fixed, on-site feed delivery systems.<br />
In addition to economic uncerta<strong>in</strong>ties<br />
over ris<strong>in</strong>g fuel costs, <strong>the</strong>re is <strong>the</strong> risk of<br />
spills while refuel<strong>in</strong>g. By virtue of <strong>the</strong>ir<br />
location, offshore farms are exposed to<br />
vast amounts of natural energy <strong>in</strong> <strong>the</strong><br />
form of w<strong>in</strong>d and waves, and <strong>in</strong> some<br />
locations, opportunities for tidal, solar,<br />
and Ocean Thermal Energy Conversion<br />
may be possible. The challenge<br />
is to develop properly scaled and affordable<br />
technology that can capture<br />
natural energy or alternatively to consider<br />
co-location of offshore aquaculture<br />
with energy production facilities<br />
(Buck et al., 2006).<br />
There has been some movement <strong>in</strong><br />
this direction over <strong>the</strong> past decade. The<br />
UNH developed a s<strong>in</strong>gle-cage feed system<br />
that was powered entirely by solar<br />
and w<strong>in</strong>d (Rice et al., 2003). Though<br />
<strong>the</strong> power requirements were small<br />
compared to commercial scale systems,<br />
this system did demonstrate <strong>the</strong> feasi-<br />
bility of us<strong>in</strong>g renewable energy to<br />
power farm equipment. More recently,<br />
<strong>the</strong> U.S. companies Resolute <strong>Mar<strong>in</strong>e</strong><br />
Energy, Inc. and Ocean Farm Technologies,<br />
Inc. have partnered on a research<br />
and demonstration project<br />
us<strong>in</strong>g Resolute <strong>Mar<strong>in</strong>e</strong>’s AirWEC<br />
wave energy converter to provide<br />
power for Ocean Farm’s AquaPod<br />
farm<strong>in</strong>g system off <strong>the</strong> Nor<strong>the</strong>ast<br />
Coast of <strong>the</strong> United States (Grydeland,<br />
2010).<br />
The recent <strong>in</strong>stallation of offshore<br />
w<strong>in</strong>d farms <strong>in</strong> Europe and planned development<br />
of farms <strong>in</strong> <strong>the</strong> United<br />
States have generated discussions with<strong>in</strong><br />
<strong>the</strong> <strong>Mar<strong>in</strong>e</strong> Spatial Plann<strong>in</strong>g process<br />
about co-location of offshore energy<br />
and food production facilities (CEQ,<br />
2009). Co-location may provide an<br />
opportunity for fish farms to access<br />
power and elim<strong>in</strong>ate <strong>the</strong> need for<br />
farm-specific generation systems. In<br />
addition to a source of power for offshore<br />
fish farms, w<strong>in</strong>d farms could potentially<br />
provide attachment po<strong>in</strong>ts for<br />
cages and stable structures for mount<strong>in</strong>g<br />
feed and communications systems<br />
(Michler-Cieluch et al., 2009).<br />
Improvements <strong>in</strong> Remote<br />
Observation<br />
Monitor<strong>in</strong>g of livestock, feed delivery,<br />
environmental conditions, and<br />
cage and moor<strong>in</strong>g <strong>in</strong>frastructure is<br />
essential for sea cage farm<strong>in</strong>g, but especially<br />
so for open ocean and submerged<br />
farms where crews may not be on site<br />
every day, and where cage depth may<br />
make observation by SCUBA more<br />
difficult. While <strong>the</strong> technologies to<br />
make most of <strong>the</strong> observations mentioned<br />
above exist, and are commercially<br />
available for near-shore surface cage<br />
farms (http://www.akvagroup.com),<br />
<strong>the</strong>y have not been systematically<br />
adapted for use <strong>in</strong> offshore submerged<br />
farm<strong>in</strong>g systems (OATP, 2007; Browdy<br />
and Hargreaves, 2009). Until <strong>the</strong>re is<br />
demonstrated demand for communications<br />
and observation systems, it is unlikely<br />
that technology companies will<br />
<strong>in</strong>vest <strong>in</strong> <strong>the</strong> production of <strong>in</strong>tegrated<br />
systems for offshore farm<strong>in</strong>g.<br />
In addition to adaptation of exist<strong>in</strong>g<br />
technologies, <strong>the</strong>re are several<br />
areas where new technology for remote,<br />
automated observation would<br />
be of benefit. Breaches <strong>in</strong> <strong>the</strong> conta<strong>in</strong>ment<br />
barrier (nett<strong>in</strong>g material), particularly<br />
small holes or tears, can easily go<br />
unnoticed, allow<strong>in</strong>g fish to escape.<br />
Remote methods of <strong>in</strong>spection (e.g.,<br />
robotics) or alternatively some type of<br />
breach alarm <strong>in</strong>corporated <strong>in</strong> <strong>the</strong> barrier<br />
material are needed to alert farm managers<br />
that action to correct <strong>the</strong> breach is<br />
required (OATP, 2007; Browdy and<br />
Hargreaves, 2009).<br />
A system for alert<strong>in</strong>g growers to<br />
mortality events and enumerat<strong>in</strong>g<br />
mortalities would be a critical improvement<br />
for fish health management<br />
and could reduce <strong>the</strong> risk to conta<strong>in</strong>ment<br />
system breaches from predators/<br />
scavengers attracted by dead fish. Technology<br />
that could enumerate mortalities<strong>in</strong>realornearreal-timewould<br />
alert managers to any health problems<br />
and allow for prompt removal without<br />
<strong>the</strong> need for costly <strong>in</strong>spection dives<br />
(Browdy and Hargreaves, 2009). Equally<br />
important would be automated systems<br />
such as airlifts that could remove dead<br />
fish from a cage without <strong>the</strong> need for<br />
divers (OATP, 2007).<br />
Technology for enumerat<strong>in</strong>g and<br />
calculat<strong>in</strong>g total <strong>in</strong>-cage biomass<br />
would also be of great benefit to offshore<br />
producers, particularly if <strong>the</strong> data can be<br />
automatically l<strong>in</strong>ked to programmable<br />
feed distribution systems (OATP,<br />
2007; Browdy and Hargreaves, 2009).<br />
The amount of feed delivered to a<br />
cage is based on a percentage of <strong>the</strong><br />
total biomass <strong>in</strong> <strong>the</strong> cage, <strong>the</strong>refore<br />
May/June 2010 Volume 44 Number 3 51
accurate measurement of total biomass<br />
is needed so that fish are not<br />
overfed (wasted feed) or underfed<br />
(sub-optimal growth). Technologies<br />
to estimate <strong>the</strong> biomass of <strong>in</strong>dividual<br />
fish exist (e.g., Vaki Biomass Counter),<br />
as are technologies to count fish (e.g.,<br />
Vaki Bioscanner Fish Counter) provided<br />
<strong>the</strong>y are channeled through a<br />
pipel<strong>in</strong>e or trough. However, automated<br />
technologies that can provide<br />
real-time accurate counts of fish <strong>in</strong> a<br />
cage do not exist. Therefore, accurate<br />
assessments of total biomass with<strong>in</strong> a<br />
cage cannot be made.<br />
Remote Communications<br />
Depend<strong>in</strong>g on <strong>the</strong> distance from<br />
shoreand<strong>the</strong>locationofland-based<br />
wireless communication networks, remote<br />
communications may be entirely<br />
possible or very difficult and costly.<br />
While satellite communications are<br />
possible from just about any location,<br />
transmission of large data streams is<br />
costly. Real-time remote transmission<br />
of stock observations (video, acoustic<br />
data) requires greater bandwidth than<br />
can be delivered by today’s affordable<br />
wireless technologies. Low-cost, reliable<br />
technologies are needed to transmit<br />
large amounts of data <strong>in</strong> real time<br />
over distances up to 20 miles. As wireless<br />
communication technology for<br />
o<strong>the</strong>r purposes cont<strong>in</strong>ues to improve,<br />
<strong>the</strong>re will likely be opportunities for<br />
offshore farmers to tap <strong>in</strong>to <strong>the</strong>se networks<br />
at a reasonable cost.<br />
Depth Control of<br />
Submersible Cages<br />
At many deep-water and oceanic<br />
sites, a seasonal <strong>the</strong>rmocl<strong>in</strong>e can develop,<br />
creat<strong>in</strong>g temperature differentials<br />
through <strong>the</strong> water column of as<br />
much as 10°C. S<strong>in</strong>ce temperature affects<br />
<strong>the</strong> feed<strong>in</strong>g, growth, and metabo-<br />
52 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
lism of <strong>the</strong> fish, it is important to<br />
position cages at depths with optimal<br />
temperature for stock performance.<br />
In addition, <strong>the</strong> ability to raise and<br />
lower a cage at a controlled speed reduces<br />
stress on fish (temperature and<br />
pressure acclimation) and provides<br />
greater opportunity for live market<strong>in</strong>g<br />
of fish with pressure-sensitive swim<br />
bladders. Therefore, precision depth<br />
controls for submersible cages would<br />
be an important advancement, particularly<br />
if vertical position<strong>in</strong>g can<br />
be automated to respond to water column<br />
temperature data (OATP, 2007;<br />
Browdy and Hargreaves, 2009).<br />
More Robust<br />
Cage Nett<strong>in</strong>g Materials<br />
Escapement of fish from sea cages<br />
due to breaches to <strong>the</strong> cage nett<strong>in</strong>g<br />
caused by human error dur<strong>in</strong>g farm<strong>in</strong>g<br />
operations, predator attacks, and fish<br />
bit<strong>in</strong>g through nett<strong>in</strong>g cont<strong>in</strong>ues to<br />
plague cage culture <strong>in</strong> protected waters<br />
(Dempster et al., 2007; Moe et al.,<br />
2007). Offshore farms are at equal or<br />
potentially greater risk as <strong>the</strong>y may be<br />
located nearer <strong>the</strong> forag<strong>in</strong>g area of large<br />
pelagic predators such as sharks and<br />
will likely have longer periods when<br />
<strong>the</strong>y are unattended by farm personnel.<br />
While as previously mentioned,<br />
remote <strong>in</strong>spection and electronic alerts<br />
for <strong>in</strong>form<strong>in</strong>g farm personnel that a<br />
breach has occurred would be welcomed,<br />
replac<strong>in</strong>g traditional woven<br />
nett<strong>in</strong>g with materials that are more resistant<br />
to damage would <strong>in</strong>crease cage<br />
security. Alternatives to woven fiber<br />
<strong>in</strong>clude copper alloy nett<strong>in</strong>g as previously<br />
mentioned, v<strong>in</strong>yl-coated wire<br />
similar to what is used to construct<br />
lobster traps, plastic materials such as<br />
Kikkonet, and v<strong>in</strong>yl-coated woven<br />
nett<strong>in</strong>g material like AquaGrid.<br />
While all <strong>the</strong>se materials offer greater<br />
resistance to tear<strong>in</strong>g, <strong>the</strong>re are poten-<br />
tially issues for some due to greater<br />
mass, difficult handl<strong>in</strong>g, and complexities<br />
with attachment to cage frames.<br />
Use of <strong>the</strong>se materials is not currently<br />
widespread; however, if <strong>the</strong> difficulties<br />
mentioned can be addressed and <strong>the</strong>y<br />
are proven to provide greater cage security,<br />
<strong>the</strong>y will likely see more widespread<br />
adoption.<br />
Future Prospects<br />
Developments <strong>in</strong> offshore mar<strong>in</strong>e<br />
cage culture over <strong>the</strong> past two decades<br />
<strong>in</strong>dicate that offshore farm<strong>in</strong>g is feasible<br />
and can be conducted <strong>in</strong> an environmentally<br />
responsible manner.<br />
However, a number of technical and<br />
operational challenges must be addressed<br />
to reduce production costs<br />
and achieve <strong>the</strong> high levels of production<br />
needed to fill <strong>the</strong> projected gap between<br />
seafood supply and demand.<br />
Therefore, cont<strong>in</strong>ued <strong>in</strong>vestment <strong>in</strong><br />
R&D from public and private sectors<br />
will be needed to reach <strong>the</strong> level of efficiency<br />
required for economic viability.<br />
In particular, research should be focused<br />
on <strong>the</strong> development of highly<br />
mechanized and fully <strong>in</strong>tegrated offshore<br />
farm<strong>in</strong>g systems to achieve greater<br />
efficiency <strong>in</strong> <strong>the</strong> conduct of rout<strong>in</strong>e operations<br />
and <strong>in</strong>sure worker safety. Integrated,<br />
“<strong>in</strong>telligent” farm<strong>in</strong>g systems<br />
with automatic feedback/neural network<br />
programm<strong>in</strong>g that can <strong>in</strong>tegrate<br />
observations (stock and environment)<br />
with operations (e.g., feed<strong>in</strong>g, harvest,<br />
grad<strong>in</strong>g) would be an important advancement<br />
for <strong>the</strong> sea cage systems of<br />
<strong>the</strong> future.<br />
Lead Author:<br />
Richard Langan<br />
Atlantic <strong>Mar<strong>in</strong>e</strong> <strong>Aquaculture</strong><br />
Center, Gregg Hall, University<br />
of New Hampshire
35 Colovos Road, Durham,<br />
NH 03824<br />
Phone: 603-862-0190<br />
Fax: 603-862-2940<br />
Email: rlangan@unh.edu<br />
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PAPER<br />
Shellfish Culture <strong>in</strong> <strong>the</strong> Open Ocean:<br />
Lessons Learned for Offshore <strong>Expansion</strong><br />
AUTHORS<br />
Daniel Cheney<br />
Pacific Shellfish Institute<br />
Richard Langan<br />
University of New Hampshire<br />
Kev<strong>in</strong> Heasman<br />
Cawthron Institute, New Zealand<br />
Bernard Friedman<br />
Santa Barbara Mariculture Co.<br />
Jonathan Davis<br />
Taylor Shellfish Farms<br />
Introduction<br />
Bivalve shellfish are a large and diverse<br />
group of animals with a worldwide<br />
distribution <strong>in</strong> almost every<br />
mar<strong>in</strong>e and freshwater environment<br />
and comprise a significant fraction<br />
of <strong>the</strong> total seafood production and<br />
consumption (Food and Agriculture<br />
Organization [FAO], 2006). Relatively<br />
few are semidomesticated for<br />
commercial aquaculture, but many<br />
more are harvested <strong>in</strong> commercial,<br />
recreational, and subsistence fisheries.<br />
These animals have unique characteristics<br />
that make <strong>the</strong>m particularly<br />
well suited to aquaculture. Most are<br />
enclosed by a hard and relatively impenetrable<br />
shell that allows <strong>the</strong> use of<br />
a wide variety of culture methods. They<br />
filter f<strong>in</strong>e food particles from <strong>the</strong> water<br />
and <strong>in</strong> <strong>the</strong>ir natural environment do<br />
not require added feed<strong>in</strong>g or food<br />
supplements. Many have a prodigious<br />
fecundity and may recruit naturally<br />
to aquatic farms or are well suited to<br />
hatchery production. Currently, large-<br />
ABSTRACT<br />
<strong>Mar<strong>in</strong>e</strong> shellfish or bivalve aquaculture accounts for a large fraction of <strong>the</strong> total<br />
world production of cultured seafood, with production trail<strong>in</strong>g only freshwater<br />
fish (ma<strong>in</strong>ly carps and similar species) and aquatic plants. However, growth of<br />
nearshore bivalve aquaculture is <strong>in</strong>creas<strong>in</strong>gly constra<strong>in</strong>ed by space, economics,<br />
human health, and environmental concerns. Offshore or open ocean waters<br />
offer a tremendous potential for expansion of <strong>the</strong> shellfish farm<strong>in</strong>g. Developments<br />
to date <strong>in</strong>dicate that it is feasible to <strong>in</strong>stall, to ma<strong>in</strong>ta<strong>in</strong>, and to operate bivalve<br />
culture systems <strong>in</strong> high-energy offshore waters with production rates often equal<strong>in</strong>g<br />
or exceed<strong>in</strong>g nearshore environments. Although production to date is limited<br />
and a number of technical, operational, economic, and social challenges must be<br />
addressed, a number of small to large-scale bivalve culture systems are <strong>in</strong> development<br />
or production. This article reviews <strong>the</strong> current production of bivalve shellfish,<br />
describes characteristics through case examples of offshore shellfish culture<br />
system, and assesses <strong>the</strong> future potential of this farm<strong>in</strong>g method.<br />
Keywords: Offshore farm<strong>in</strong>g, Site selection, System design, Bivalve mollusks,<br />
Environmental effects<br />
scale commercial shellfish cultivation<br />
is generally limited to sheltered mar<strong>in</strong>e<br />
and estuar<strong>in</strong>e waters us<strong>in</strong>g on-<strong>the</strong>ground<br />
or suspended culture methods.<br />
However, <strong>in</strong> recent years, decl<strong>in</strong><strong>in</strong>g<br />
water quality, a lack of suitable nearshore<br />
grow<strong>in</strong>g areas, <strong>in</strong>creas<strong>in</strong>g user<br />
conflicts <strong>in</strong> those areas, and a need to<br />
expand production to meet market demands<br />
have prompted efforts to develop<br />
offshore or open water bivalve<br />
aquaculture.<br />
Shellfish or bivalve aquaculture accounts<br />
for a large fraction of <strong>the</strong> total<br />
world production of cultured seafood,<br />
with production trail<strong>in</strong>g only freshwater<br />
fish (ma<strong>in</strong>ly carps and similar<br />
species) and aquatic plants (Figure 1).<br />
The world aquaculture production<br />
of bivalves is now over 13 million<br />
metric tons and is nearly double <strong>the</strong><br />
fishery harvest Figure 2 (FAO,<br />
2009). In <strong>the</strong> United States, shellfish<br />
accounted for approximately 30% of<br />
<strong>the</strong> total domestic aquaculture production<br />
of 159,000 metric tons <strong>in</strong><br />
2007 (FAO, 2009). It is a traditional<br />
and expand<strong>in</strong>g <strong>in</strong>dustry on <strong>the</strong> West<br />
Coast and an expand<strong>in</strong>g <strong>in</strong>dustry <strong>in</strong><br />
<strong>the</strong> eastern and sou<strong>the</strong>rn United<br />
States. Historically, oysters accounted<br />
for <strong>the</strong> bulk of <strong>the</strong> production, but <strong>in</strong><br />
recent years o<strong>the</strong>r bivalve shellfish<br />
have become <strong>in</strong>creas<strong>in</strong>gly important<br />
(FAO, 2009; U.S. Department of<br />
Agriculture, 2006). These <strong>in</strong>clude<br />
mussels; hard, softshell, Manila, and<br />
geoduck clams; and scallops. Although<br />
U.S. aquaculture production<br />
of <strong>the</strong>se species is <strong>in</strong>creas<strong>in</strong>g, it does<br />
notmeet<strong>the</strong>domesticdemandfor<br />
shellfish, nor does it provide sufficient<br />
opportunities for export of shellfish<br />
products.<br />
May/June 2010 Volume 44 Number 3 55
FIGURE 1<br />
World (top) and U.S. (bottom) aquaculture<br />
production as a percentage of total reported<br />
harvest volumes. Molluscan production <strong>in</strong>cludes<br />
all mar<strong>in</strong>e and freshwater species<br />
(FAO, 2009).<br />
It is <strong>the</strong> purpose of this article to review<br />
through case studies, <strong>the</strong> current<br />
status of open water bivalve shellfish<br />
culture, and comment on <strong>the</strong> benefits,<br />
challenges, and constra<strong>in</strong>ts for largescale<br />
offshore shellfish production.<br />
FIGURE 2<br />
Overview of Current Status<br />
Offshore Farm<strong>in</strong>g Incentives<br />
and Constra<strong>in</strong>ts<br />
There are real limitations to landbased<br />
and nearshore bivalve shellfish<br />
culture because of social, environmental,<br />
economic, and resource constra<strong>in</strong>ts.<br />
With <strong>the</strong> exception of hatchery and<br />
nursery production, <strong>the</strong> space and <strong>the</strong><br />
volume of phytoplankton required to<br />
grow to market-size bivalve shellfish<br />
<strong>in</strong> land-based systems are enormous<br />
and <strong>the</strong>refore not economically viable.<br />
For nearshore shellfish farm<strong>in</strong>g, available<br />
and suitable space is becom<strong>in</strong>g<br />
limit<strong>in</strong>g factor as farmers must compete<br />
with a variety of o<strong>the</strong>r waterfront<br />
users and commercial and recreational<br />
activities. Shellfish producers <strong>in</strong> <strong>the</strong><br />
o<strong>the</strong>rwise highly productive grow<strong>in</strong>g<br />
waters can be prevented or restricted<br />
from expand<strong>in</strong>g <strong>in</strong>to new farm sites<br />
by coastal regulatory processes favor<strong>in</strong>g<br />
o<strong>the</strong>r waterfront and sometimes<br />
non-water-dependent uses (Dickson,<br />
1992; Hamouda et al., 2004). Conflicts<br />
with coastal residents and touristrelated<br />
bus<strong>in</strong>esses over views from<br />
shorefront property and beach access<br />
can also adversely affect <strong>the</strong> permitt<strong>in</strong>g<br />
of new farm<strong>in</strong>g sites (Hamouda et al.,<br />
2004). In addition, rapid population<br />
growth and <strong>the</strong> result<strong>in</strong>g <strong>in</strong>crease <strong>in</strong><br />
World bivalve molluscan shellfish production (all species) for <strong>the</strong> fishery and aquaculture sectors,<br />
1950–2007 (FAO, 2009).<br />
56 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
human sources of pollution may affect<br />
<strong>the</strong> sanitary quality of nearshore<br />
waters, sometimes clos<strong>in</strong>g those waters<br />
for shellfish production (Glasoe and<br />
Christy, 2005). As a consequence, o<strong>the</strong>rwise<br />
suitable sites for nearshore shellfish<br />
culture can be off limits because<br />
of public policy and health restrictions.<br />
Farm<strong>in</strong>g <strong>in</strong> offshore mar<strong>in</strong>e waters<br />
<strong>in</strong> <strong>the</strong> United States is a potential option<br />
for <strong>in</strong>creas<strong>in</strong>g bivalve shellfish<br />
production; however, farm<strong>in</strong>g <strong>in</strong> fully<br />
exposed offshore waters requires a firm<br />
understand<strong>in</strong>g of site conditions, biological<br />
responses and factors, and appropriate<br />
culture methods. Attention<br />
must be given to (1) general water<br />
quality conditions and water current<br />
and wave dynamics; (2) <strong>the</strong> quantity,<br />
quality, and seasonality of phytoplankton<br />
available for filter feed<strong>in</strong>g bivalves;<br />
(3) <strong>the</strong> frequency and duration of harmful<br />
algal blooms (HABs)—bivalves can<br />
accumulate <strong>the</strong> associated biotox<strong>in</strong>s,<br />
such as domoic acid produc<strong>in</strong>g diatoms<br />
off <strong>the</strong> U.S. west coast, which<br />
can result <strong>in</strong> extended public health<br />
closures and economic impact on producers;<br />
(4) a selection of <strong>the</strong> culture<br />
species, determ<strong>in</strong>ation of yield (based<br />
on growth and mortality), biofoul<strong>in</strong>g,<br />
predation, and o<strong>the</strong>r biological factors;<br />
(5) suitable eng<strong>in</strong>eer<strong>in</strong>g and open<br />
water culture approaches—equipment<br />
and methods currently used for shellfish<br />
production <strong>in</strong> protected nearshore<br />
waters are largely unsuitable for <strong>the</strong><br />
open ocean; (6) meet<strong>in</strong>g local and federal<br />
regulatory, permitt<strong>in</strong>g, and environmental<br />
requirements; and (7)<br />
hav<strong>in</strong>g sufficient experience, management<br />
skills, and f<strong>in</strong>ancial resources<br />
to effectively apply technologies and<br />
methods for offshore shellfish farm<strong>in</strong>g.<br />
Despite <strong>the</strong>se challenges, <strong>the</strong>re is<br />
sufficient rationale for pursu<strong>in</strong>g <strong>the</strong><br />
development of offshore farm<strong>in</strong>g. Favorable<br />
features of open ocean waters
<strong>in</strong>clude (1) ample space for expansion,<br />
(2) typically excellent growth and<br />
yields and low mortalities, (3) reduced<br />
conflict with many user groups, (4)<br />
lower exposure to human sources of<br />
pollution, and (5) m<strong>in</strong>imization of<br />
<strong>the</strong> negative environmental and aes<strong>the</strong>tic<br />
impacts (Buck et al., 2003).<br />
Bivalve Species Suited for<br />
Culture <strong>in</strong> Offshore Environments<br />
There are a number of species of<br />
bivalve mollusks that can be farmed<br />
<strong>in</strong> offshore waters. Efforts to date<br />
have focused primarily on several mussel<br />
species and, to a lesser extent, on<br />
scallops and oysters. Mussels are a preferred<br />
species because of <strong>the</strong>ir rapid<br />
growth to market size and natural<br />
method of attachment with a “byssus”<br />
toobjects<strong>in</strong><strong>the</strong>water.Also,asthis<br />
technology is relatively new, <strong>the</strong> sector<br />
is still <strong>in</strong> an early stage of development,<br />
and production at <strong>in</strong>dividual farm sites<br />
is small by comparison with nearshore<br />
farms. However, new offshore farms<br />
are proposed or under development<br />
which will, at full production, exceed<br />
<strong>the</strong> capacities of many nearshore<br />
farms. Most are sited <strong>in</strong> locations<br />
where <strong>in</strong>shore farms are ei<strong>the</strong>r fully<br />
developed or are impractical given<br />
<strong>the</strong> nature of <strong>the</strong> nearshore environment.<br />
The locations and <strong>the</strong> species<br />
cultured at a number of selected worldwide<br />
sites are shown <strong>in</strong> Table 1.<br />
Technologies for Offshore<br />
Shellfish Farm<strong>in</strong>g<br />
All bivalve shellfish are raised to<br />
market size us<strong>in</strong>g variations of onbottom<br />
or suspended open water<br />
culture systems. Bottom culture of<br />
shellfish is often seen as a traditional<br />
enterprise and is commonly practiced<br />
<strong>in</strong> <strong>in</strong>tertidal and shallow subtidal<br />
waters. Off-bottom culture is a preferred<br />
method <strong>in</strong> many areas of <strong>the</strong><br />
TABLE 1<br />
Locations and species cultured at selected offshore shellfish farm sites.<br />
Location Species<br />
North America Atlantic Canada<br />
New England<br />
Blue mussel Mytilus edulis<br />
Santa Barbara Mediterranean Mytilus galloprov<strong>in</strong>cialis<br />
Channel<br />
mussel<br />
Pacific oyster Crassostrea gigas<br />
Strait of Juan de Fuca Rock scallop Crassedoma giganteum<br />
Europe France, Mediterranean Mediterranean M. galloprov<strong>in</strong>cialis<br />
coast<br />
mussel<br />
Germany, North Sea<br />
Belgium, North Sea<br />
Ireland<br />
Blue mussel M. edulis<br />
Portugal, Spa<strong>in</strong>, Mediterranean M. galloprov<strong>in</strong>cialis<br />
and Italy<br />
mussel<br />
Asia Japan Japanese scallop Pat<strong>in</strong>opecten yessoensis<br />
Oceania New Zealand Greenshell mussel Perna canaliculus<br />
Australia Pacific oyster C. gigas<br />
Blue mussel M. edulis<br />
Source: Case Examples 1 to 3; Buck (2007); Davis (2003); Jeffs (2003); Plew et al. (2005); Thompson<br />
(1996); and Van Nieuwenhove and Delbare (2008).<br />
world and is used <strong>in</strong> <strong>the</strong> United States<br />
and Canada for nearshore mussel and<br />
oyster culture. With <strong>the</strong> exception of<br />
bottom seed<strong>in</strong>g of scallop spat <strong>in</strong> offshore<br />
waters, practiced <strong>in</strong> Japan, New<br />
Zealand, and Canada, technologies<br />
for offshore shellfish farm<strong>in</strong>g are essentially<br />
adaptations of <strong>the</strong> off bottom<br />
culture methods currently used <strong>in</strong> protected<br />
nearshore waters. Submerged<br />
longl<strong>in</strong>es are <strong>the</strong> most commonly<br />
used method (Langan, 2011), although<br />
an alternate technology us<strong>in</strong>g<br />
a submerged cyl<strong>in</strong>der was tested for<br />
rock scallop culture off <strong>the</strong> northwest<br />
U.S. coast (Case Example 3), and<br />
small quantities of oysters are cage cultured<br />
<strong>in</strong> open waters as well (see Case<br />
Example 2). Submerged longl<strong>in</strong>e technology<br />
was developed <strong>in</strong> Japan and has<br />
been <strong>in</strong> use <strong>the</strong>re for several decades for<br />
deep-water-suspended scallop culture<br />
and <strong>in</strong> atoll lagoons and protected<br />
reef areas of <strong>the</strong> south Pacific for pearl<br />
oyster culture. Currently, <strong>the</strong> technology<br />
is prov<strong>in</strong>g to be effective for mussel<br />
production <strong>in</strong> very high-energy<br />
open ocean conditions (e.g., significant<br />
wave heights > 10 m) at farm sites<br />
<strong>in</strong> New Zealand (Case Example 1) <strong>in</strong><br />
sou<strong>the</strong>rn California on <strong>the</strong> U.S. west<br />
coast (Case Example 3).<br />
Most of <strong>the</strong> current technologies<br />
are quite simple and use relatively <strong>in</strong>expensive<br />
materials. They range from<br />
surface float<strong>in</strong>g, semisubmerged to<br />
fully submerged systems accord<strong>in</strong>g to<br />
local conditions. Adapt<strong>in</strong>g various designs<br />
of rafts typically used <strong>in</strong> more<br />
sheltered waters has not proved to be<br />
May/June 2010 Volume 44 Number 3 57
economically or technically feasible <strong>in</strong><br />
<strong>the</strong>offshoreenvironment.Thesubmerged<br />
longl<strong>in</strong>e is a tensioned system<br />
ma<strong>in</strong>ta<strong>in</strong>ed by <strong>the</strong> oppos<strong>in</strong>g forces of<br />
submerged flotation at <strong>the</strong> ends of a<br />
s<strong>in</strong>gle horizontal backbone, connected<br />
by l<strong>in</strong>es set at a 45° angle to seafloor<br />
anchors. Submergence depth of <strong>the</strong><br />
backbone is dictated by site-specific<br />
wave climate and can range from 3 to<br />
15 m. Surface floatation is m<strong>in</strong>imized<br />
to prevent <strong>the</strong> transfer of wave<strong>in</strong>duced<br />
motion of <strong>the</strong> backbone and<br />
consists of nonstructural marker<br />
buoys for <strong>the</strong> anchor l<strong>in</strong>es and a midbackbone<br />
pickup l<strong>in</strong>e that provides access<br />
to <strong>the</strong> crop from a service vessel.<br />
Anchors are generally spaced from<br />
100 to 200 m apart, and depend<strong>in</strong>g<br />
upon <strong>the</strong> depth of <strong>the</strong> water and desired<br />
depth of submergence, <strong>the</strong> backbone<br />
length can range from 70 to 130 m<br />
(Langan, 2011; Buck et al., 2006).<br />
Depend<strong>in</strong>g on <strong>the</strong> species, shellfish<br />
seed or juveniles for those farms<br />
are sourced ei<strong>the</strong>r from hatcheries or<br />
from <strong>the</strong> wild. Ropes or “droppers”<br />
of mussels and cages of scallops or<br />
oysters are suspended from <strong>the</strong> backbone,<br />
and additional submerged floatation<br />
is added as <strong>the</strong> crop ga<strong>in</strong>s mass<br />
dur<strong>in</strong>g grow out. Fish<strong>in</strong>g boats or<br />
specialized vessels designed to carry<br />
product and harvest<strong>in</strong>g and primary<br />
process<strong>in</strong>g gear are used to tend <strong>the</strong><br />
longl<strong>in</strong>es.<br />
Shellfish Growth and Yields<br />
from Offshore Farms<br />
Although data are limited to a<br />
few test sites <strong>in</strong> North America, New<br />
Zealand, and Europe, <strong>the</strong>re are <strong>in</strong>dications<br />
that production cycles and product<br />
quality for bivalve shellfish grown<br />
<strong>in</strong> offshore waters are highly favorable.<br />
Offshore farms on <strong>the</strong> New<br />
Hampshire coast <strong>in</strong> <strong>the</strong> Nor<strong>the</strong>ast<br />
United States consistently produced<br />
58 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
market-sized (55-mm) blue mussels<br />
<strong>in</strong> 12–14 months from spat settlement<br />
with meat yields rang<strong>in</strong>g from 42%<br />
to 58% (Langan and Horton, 2003).<br />
By comparison, blue mussels from<br />
nearby estuaries and bays can take up<br />
to 18 months to reach market size<br />
(Langan, 2011). Mediterranean mussels<br />
produced at an open ocean site<br />
<strong>in</strong> California also demonstrate good<br />
growth and quality, grow<strong>in</strong>g from a<br />
1-mm seed to a 75-mm-long marketsized<br />
product <strong>in</strong> 10–12 months (Case<br />
Example 2). Similar production<br />
efficiencies with excellent growth<br />
and meat condition were reported for<br />
Greenshell mussels from two pilotscale<br />
farm sites <strong>in</strong> New Zealand (Case<br />
Example 1). Faster growth at <strong>the</strong>se<br />
offshore sites may to be due to a<br />
more stable temperature and sal<strong>in</strong>ity<br />
conditions and <strong>the</strong>refore lower stress,<br />
reduced turbidity, and better water<br />
exchange.<br />
Environmental<br />
Considerations<br />
Bivalve shellfish culture is generally<br />
perceived as environmentally benign<br />
and beneficial with significant<br />
water quality and ecological benefits<br />
(Shumway et al., 2003). However,<br />
<strong>the</strong>re can be environmental impacts<br />
that merit consideration dur<strong>in</strong>g<br />
development of offshore farms,<br />
<strong>in</strong>clud<strong>in</strong>g <strong>the</strong> follow<strong>in</strong>g (Langan,<br />
2007; Richard Langan, personal<br />
communications):<br />
1. Enrichment of bottom sediments:<br />
Deposition of feces and pseudofeces<br />
has been associated with very<br />
dense three-dimensional culture<br />
systems <strong>in</strong> shallow embayments<br />
under conditions of poor or limited<br />
water circulation (Cranford et al.,<br />
2009; Grant et al., 2005). If threedimensional<br />
farms are sited <strong>in</strong> loca-<br />
tions with sufficient depth and<br />
adequate water circulation to disperse<br />
wastes, enrichment of bottom<br />
sediments should not be an<br />
issue but needs to be <strong>in</strong>vestigated<br />
on a site-by-site basis (Brigol<strong>in</strong> et al.,<br />
2009).<br />
2. Food depletion: High-density<br />
shellfish culture can deplete <strong>the</strong><br />
water column of planktonic food,<br />
affect<strong>in</strong>g both <strong>the</strong> growth and <strong>the</strong><br />
fitness of <strong>the</strong> cultured organisms<br />
as well as naturally occurr<strong>in</strong>g filter<br />
feeders <strong>in</strong> <strong>the</strong> system (Pr<strong>in</strong>s et al.,<br />
1997). This is unlikely to be an<br />
environmental issue <strong>in</strong> offshore<br />
waters, but at large, <strong>the</strong> high-density<br />
offshore farms, <strong>the</strong> potential depletion<br />
of food with<strong>in</strong> <strong>the</strong> farm, and<br />
<strong>the</strong> reduced growth and condition<br />
of <strong>the</strong> stock need to be assessed<br />
<strong>in</strong> carry<strong>in</strong>g capacity models such<br />
as <strong>the</strong> Farm <strong>Aquaculture</strong> Resource<br />
Management model.<br />
3. Effects of culture systems on water<br />
flow: Flow modifications with<strong>in</strong><br />
culture systems have been observed<br />
<strong>in</strong> relatively shallow water nearshore<br />
and offshore farm sites.<br />
Offshore development submerged<br />
culture <strong>in</strong> much deeper water<br />
(30–100 m) with ample space<br />
above and below <strong>the</strong> culture arrays<br />
are unlikely to result <strong>in</strong> similar<br />
flow modifications (Langan, 2011;<br />
Stevensetal.,2008).Futuredevelopment<br />
would benefit from a reliable<br />
database and extension of methodologies<br />
to predict effects of culture<br />
systems on water flow and currents<br />
(Ferreira et al., 2007; Stevens et al.,<br />
2008).<br />
4. Interactions with mar<strong>in</strong>e mammals<br />
and birds: The deployment<br />
of seed collection and culture systems<br />
with<strong>in</strong> <strong>the</strong> migratory pathways<br />
of div<strong>in</strong>g ducks and mar<strong>in</strong>e<br />
mammals requires site-specific
assessments and local knowledge<br />
of <strong>the</strong> movement, tim<strong>in</strong>g, and behavior<br />
of <strong>the</strong>se animals (Richard<br />
Langan, personal communications).<br />
In addition, small seed and<br />
juvenile shellfish can be subject<br />
to <strong>in</strong>tense predation by div<strong>in</strong>g<br />
ducks, requir<strong>in</strong>g adjustments to<br />
<strong>the</strong> locations and/or depths of<br />
<strong>the</strong> culture systems (see Case Example<br />
3).<br />
5. <strong>Mar<strong>in</strong>e</strong> spatial plann<strong>in</strong>g: Offshore<br />
shellfish culture systems could<br />
potentially come <strong>in</strong> conflict with<br />
coastal fisheries, vessel operations,<br />
and passive recreational activities<br />
or be damaged by those activities.<br />
These issues may be reflected <strong>in</strong><br />
regulatory guidance affect<strong>in</strong>g <strong>the</strong><br />
social environment such as <strong>the</strong><br />
proposed U.S. National Offshore<br />
<strong>Aquaculture</strong> Act of 2007 (http://<br />
aquaculture.noaa.gov/us/2007.<br />
html) or environmental, ocean<br />
leas<strong>in</strong>g, and fisheries management<br />
policies of <strong>the</strong> permitt<strong>in</strong>g authorities.<br />
However, <strong>the</strong>y are often <strong>the</strong><br />
most time-consum<strong>in</strong>g and contentious<br />
aspects of aquatic farm<br />
development. Therefore, an <strong>in</strong>tegrated<br />
mar<strong>in</strong>e spatial plann<strong>in</strong>g<br />
approach is essential, particularly<br />
for large-scale or multiple farm<br />
proposals (http://www.unescoioc-mar<strong>in</strong>esp.be/mar<strong>in</strong>e_spatial_<br />
plann<strong>in</strong>g_msp).<br />
Case Examples<br />
The follow<strong>in</strong>g three case examples<br />
offer an <strong>in</strong>dication of <strong>the</strong> extent and<br />
types of open ocean shellfish farm<strong>in</strong>g<br />
proposed and underway <strong>in</strong> New<br />
Zealand (Case Example 1) and <strong>the</strong><br />
U.S. West Coast (Case Examples 2<br />
and 3). Worldwide, examples of locations<br />
with farms <strong>in</strong> operation or<br />
projected are shown <strong>in</strong> Table 1.<br />
Case Example 1: Mussel and<br />
Oyster Farm<strong>in</strong>g <strong>in</strong> New Zealand<br />
Bivalve shellfish farm<strong>in</strong>g has a<br />
long history <strong>in</strong> New Zealand, with<br />
<strong>the</strong> most notable example be<strong>in</strong>g <strong>the</strong><br />
culture of <strong>the</strong> Greenshell mussels<br />
(Perna canaliculus) <strong>in</strong> <strong>the</strong> sheltered<br />
waters of Marbourgh Sounds near<br />
Nelson on <strong>the</strong> South Island. Beg<strong>in</strong>n<strong>in</strong>g<br />
<strong>in</strong> 1999, prompted by high mussel<br />
demand and prices and a shortage<br />
of space <strong>in</strong> sheltered waters due <strong>in</strong><br />
part to social pressures, growers<br />
began work<strong>in</strong>g with <strong>the</strong> Cawthron Institute,<br />
Nelson, New Zealand, to look<br />
to offshore farm sites for this and o<strong>the</strong>r<br />
species. Research was undertaken on<br />
sites <strong>in</strong> Hawke Bay and near Opotiki<br />
<strong>in</strong> <strong>the</strong> Bay of Plenty on <strong>the</strong> North<br />
Island east coast (Figure 3). After rigorous<br />
environmental assessment and<br />
monitor<strong>in</strong>g, both sites were subsequently<br />
issued shellfish farm<strong>in</strong>g permits.<br />
Two small and one large offshore<br />
FIGURE 3<br />
culture sites have subsequently been<br />
permitted on <strong>the</strong> South Island. The<br />
Opotiki site development is due to<br />
start <strong>in</strong> early 2010, <strong>the</strong> Hawke Bay<br />
site will follow. Both sites are considered<br />
<strong>in</strong> this case study.<br />
Site Descriptions<br />
TheOpotikisite(Figure4)is<br />
3,800 ha (9,400 ac) <strong>in</strong> size. It is<br />
8km(5miles)from<strong>the</strong>closestland<br />
and 9 km (5.5 miles) from <strong>the</strong> nearest<br />
port and <strong>in</strong> water rang<strong>in</strong>g from 30 to<br />
50 m (100–160 ft) deep. The Hawke<br />
Bay site is 2,100 ha (5,200 ac) <strong>in</strong> extent.<br />
It is 6 km (3.7 miles) from land<br />
and 16 km (10 miles) from port at its<br />
nearest po<strong>in</strong>t. Research <strong>in</strong>to <strong>the</strong> potential<br />
of both sites started <strong>in</strong> 2003 with<br />
<strong>the</strong> <strong>in</strong>stallation of research moor<strong>in</strong>gs<br />
for <strong>the</strong> culture of shellfish. Work on<br />
aspects of phytoplankton (<strong>in</strong>clud<strong>in</strong>g<br />
toxic species), seston, water temperature<br />
profiles, w<strong>in</strong>d and waves, water<br />
North Island, New Zealand show<strong>in</strong>g <strong>the</strong> locations of permitted open ocean shellfish farms.<br />
May/June 2010 Volume 44 Number 3 59
FIGURE 4<br />
The Opotiki site <strong>in</strong> <strong>the</strong> Bay of Plenty, North<br />
Island, New Zealand.<br />
currents, benthic fauna, and biofoul<strong>in</strong>g<br />
extend<strong>in</strong>g to mid-2008. Bivalve<br />
growth and condition were measured<br />
on mussels (P. canaliculus), Pacific<br />
oysters (Crassostrea gigas), and scallops<br />
(Pecten novaezelandiae) at depths rang<strong>in</strong>gfrom10to30m.Modelswere<br />
developed to assist with <strong>the</strong> design of<br />
structural systems and to predict <strong>the</strong><br />
<strong>in</strong>fluences of wave size, duration, and<br />
direction. These models provided <strong>in</strong>formation<br />
on <strong>the</strong> stresses developed<br />
throughout <strong>the</strong> structure and <strong>the</strong><br />
reaction of <strong>the</strong> structure and shellfish<br />
culture l<strong>in</strong>es to ocean energy.<br />
Monitor<strong>in</strong>g Results<br />
Water temperature, currents, w<strong>in</strong>d,<br />
and waves are key factors affect<strong>in</strong>g <strong>the</strong><br />
viability of aquaculture <strong>in</strong> an offshore<br />
environment. Water temperature not<br />
only determ<strong>in</strong>es which species can be<br />
grown but has implications for food<br />
supply because of <strong>the</strong>rmal stratification.<br />
Currents are critically important<br />
for both food delivery and <strong>the</strong> removal<br />
and dispersion of waste. In an offshore<br />
environment, w<strong>in</strong>d and waves determ<strong>in</strong>e<br />
<strong>the</strong> structural design requirements<br />
of <strong>the</strong> farm and service vessels.<br />
Temperature profiles for both sites<br />
show a consistent warm<strong>in</strong>g of <strong>the</strong><br />
upper water column <strong>in</strong> summer with<br />
60 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
some stratification and a cooler, more<br />
mixed water column dur<strong>in</strong>g w<strong>in</strong>ter. In<br />
general, temperature patterns are consistent<br />
from one year to <strong>the</strong> next. At<br />
both sites, currents do not differ substantially<br />
from those at <strong>in</strong>shore sites.<br />
Hawke Bay is characterized by slow<br />
currents(lessthan10cm/sor0.2knot)<br />
flow<strong>in</strong>g west for <strong>the</strong> majority of <strong>the</strong><br />
time, with stronger eastward currents<br />
(up to 50 cm/s (1 knot) at <strong>the</strong> surface<br />
and 30 cm/s (0.6 knot) at mid-water)<br />
occurr<strong>in</strong>g <strong>in</strong>frequently. In contrast,<br />
w<strong>in</strong>d-driven circulation tends to dom<strong>in</strong>ate<br />
at <strong>the</strong> Opotiki site (mostly below<br />
15 cm/s, but up to 30 cm/s), which<br />
also has a stronger tidal <strong>in</strong>fluence<br />
than Hawke Bay.<br />
Wave models were used to provide<br />
long-term estimates of <strong>the</strong> wave climate<br />
at <strong>the</strong> Hawke Bay and Opotiki<br />
sites, with short-term <strong>in</strong>strument<br />
deployments at Hawke Bay for validation.<br />
The majority of waves at <strong>the</strong><br />
Hawke Bay site are moderate (frequent<br />
waves of up to 2 m or 6.5 ft) and from<br />
<strong>the</strong> sou<strong>the</strong>ast, although waves up to<br />
4m(13ft)werenotuncommon.<br />
Modeled data for <strong>the</strong> eastern Bay of<br />
Plenty <strong>in</strong>dicate a slighter higher occurrence<br />
of 1 to 3 m waves compared with<br />
<strong>the</strong> Hawke Bay site. However, <strong>the</strong>se<br />
data were for a site fur<strong>the</strong>r offshore<br />
than <strong>the</strong> Opotiki research site. The degree<br />
of coastal protection at <strong>the</strong> actual<br />
site is likely to result <strong>in</strong> a wave climate<br />
similar to that of Hawke Bay although<br />
hurricane <strong>in</strong>duced waves <strong>in</strong> <strong>the</strong> Pacific<br />
do make an appearance occasionally.<br />
Both sites can expect rare occurrences<br />
of waves of up to 12m (40 ft).<br />
Vessel Access<br />
Vessel access is an important consideration<br />
<strong>in</strong> assess<strong>in</strong>g economic feasibility<br />
of offshore farm<strong>in</strong>g, <strong>in</strong> terms<br />
of both ma<strong>in</strong>tenance and harvest<strong>in</strong>g<br />
operations. Characteriz<strong>in</strong>g <strong>the</strong> pre-<br />
dom<strong>in</strong>ant physical conditions allowed<br />
estimates of site accessibility. A vessel<br />
able to work <strong>in</strong> waves up to 3 m <strong>in</strong><br />
size could access <strong>the</strong> Hawke Bay site<br />
between 70% and 100% of <strong>the</strong> time.<br />
In contrast, with a vessel only able to<br />
work <strong>in</strong> waves up to 1 m, access to<br />
<strong>the</strong> site could be restricted to 10%<br />
for a given month. In addition, access<br />
to <strong>the</strong> site for more than 80% of <strong>the</strong><br />
time <strong>in</strong> any month will require a vessel<br />
that can tolerate average w<strong>in</strong>ds of up<br />
to 13 m/s (47 km/h or 25 knots) and<br />
gusts that may be substantially higher.<br />
Although larger boats are able to work<br />
<strong>in</strong> rougher conditions, <strong>the</strong>y have more<br />
w<strong>in</strong>dage than smaller vessels, mak<strong>in</strong>g<br />
<strong>the</strong>m less able to work <strong>in</strong> high w<strong>in</strong>d<br />
conditions. Therefore, design<strong>in</strong>g a<br />
vessel to maximize access to an open<br />
ocean site and safety to <strong>the</strong> crew requires<br />
careful consideration.<br />
Productivity of <strong>the</strong> Grow<strong>in</strong>g<br />
Environment and Shellfish Growth<br />
Primary productivity of <strong>the</strong> open<br />
ocean sites is strongly, if not entirely,<br />
<strong>in</strong>fluenced by oceanic processes, differ<strong>in</strong>g<br />
from farmed <strong>in</strong>shore areas that<br />
receive constant land-derived <strong>in</strong>put of<br />
nutrients. The grow<strong>in</strong>g environment<br />
at <strong>the</strong> Hawke Bay site was characterized<br />
by low concentrations of chlorophyll<br />
a (mean = 0.8 μg/l, m<strong>in</strong> = 0.13 μg/l,<br />
max = 5.63 μg/l), a key <strong>in</strong>dicator of<br />
phytoplankton supply, particularly <strong>in</strong><br />
summer when <strong>the</strong> upper waters become<br />
impoverished (∼0.2 μg/l) dur<strong>in</strong>g<br />
periods of <strong>the</strong>rmal stratification. The<br />
Opotikisitehadameanchlorophyll<br />
a level through <strong>the</strong> water column of<br />
1.14 μg/l (m<strong>in</strong> = 0.12 μg/l, max =<br />
9.17 μg/l). Higher chlorophyll a concentrations<br />
at <strong>the</strong> Opotiki site suggest<br />
it would be slightly more conducive to<br />
farm<strong>in</strong>g than Hawke Bay.<br />
Although Greenshell mussels are<br />
generally thought to require chlorophyll
at concentrations around 1 μg/l for<br />
growth, mussels at both sites achieved<br />
good growth and condition dur<strong>in</strong>g<br />
more than one season (Figure 5). Average<br />
growth rates and times taken<br />
to achieve a harvestable size of about<br />
80 mm (3 <strong>in</strong>ches) (372 and 487 days<br />
for Opotiki and Hawke Bay, respectively)<br />
compare well with those of<br />
mussels cultured <strong>in</strong>shore and are faster<br />
than for some wild populations. The<br />
excellent growth was perhaps susta<strong>in</strong>ed<br />
at <strong>the</strong> sites by relatively high seston<br />
quality despite low chlorophyll a concentrations.<br />
It is also possible that <strong>the</strong>re<br />
are as yet undocumented aspects of<br />
mussel physiology that allow <strong>the</strong> animals<br />
to adapt to new environments.<br />
FIGURE 5<br />
Mature mussels at 15-m depth on <strong>the</strong> open<br />
ocean farm.<br />
O<strong>the</strong>r Ecological Observations<br />
O<strong>the</strong>r <strong>in</strong>vestigations <strong>in</strong>cluded specific<br />
studies of seabed ecology (for environmental<br />
monitor<strong>in</strong>g purposes),<br />
prevalence of crayfish (rock lobster)<br />
juvenile or puerulus settlement (due<br />
to ramifications for commercial<br />
fish<strong>in</strong>g), and <strong>the</strong> prevalence and succession<br />
of biofoul<strong>in</strong>g communities<br />
(which have both farm<strong>in</strong>g and biosecurity<br />
implications). By <strong>the</strong>ir nature,<br />
open ocean sites are likely to be situated<br />
over deep, soft sediment habitats<br />
on <strong>the</strong> cont<strong>in</strong>ental shelf with relatively<br />
low ecological diversity. Soft sediment<br />
communities <strong>in</strong> this study were not<br />
impacted by farm deposition o<strong>the</strong>r<br />
than low quantities of shell drop-off<br />
from <strong>the</strong> ropes. The potential for environmental<br />
impacts from offshore sites<br />
is likely to be mitigated by <strong>the</strong> typically<br />
high-energy environment, aid<strong>in</strong>g<br />
waste assimilation and dispersal.<br />
Foul<strong>in</strong>gwasgenerallylowcompared<br />
with o<strong>the</strong>r known coastal or<br />
<strong>in</strong>shore sites. Even when foul<strong>in</strong>g occurred,<br />
<strong>the</strong> higher energy experienced<br />
<strong>in</strong> <strong>the</strong> open ocean facilitated enough<br />
water movement to enable growth of<br />
organisms. F<strong>in</strong>ally, dur<strong>in</strong>g <strong>the</strong> period<br />
of sampl<strong>in</strong>g (2005–2008), settlement<br />
of pueruli was sporadic and <strong>in</strong>frequent.<br />
The low prevalence of space between<br />
<strong>the</strong> mussels on <strong>the</strong> ropes provides little<br />
opportunity for a settl<strong>in</strong>g puerulus to<br />
metamorphose. Settlement is <strong>the</strong>refore<br />
not expected to occur at levels that<br />
would be significant for <strong>the</strong> commercial<br />
crayfish <strong>in</strong>dustry.<br />
The Future of Open Ocean Shellfish<br />
<strong>Aquaculture</strong> <strong>in</strong> <strong>the</strong> Case Area<br />
One of <strong>the</strong> basic premises for conduct<strong>in</strong>g<br />
this assessment was that <strong>the</strong><br />
open ocean environment was sufficiently<br />
different to <strong>the</strong> traditional<br />
<strong>in</strong>shore environments to warrant consider<strong>in</strong>g<br />
new approaches to farm<strong>in</strong>g.<br />
The exposed and potentially expansive<br />
environment poses both new opportunities<br />
and new challenges. One of<br />
<strong>the</strong> more obvious opportunities is<br />
more space, which is essential if New<br />
Zealand is to substantially <strong>in</strong>crease shellfish<br />
production. Fur<strong>the</strong>rmore, large<br />
areas (e.g., >1,000 ha or 2,500 ac) also<br />
provide an opportunity to experiment<br />
with farm configurations to improve<br />
resource utilization and susta<strong>in</strong>ability.<br />
For example, l<strong>in</strong>e spac<strong>in</strong>g may be <strong>in</strong>creased<br />
to promote water flow with<strong>in</strong><br />
<strong>the</strong> farm, and it is possible to <strong>in</strong>troduce<br />
<strong>in</strong>novative polyculture or “multi-<br />
trophic level” arrangements, which may<br />
<strong>in</strong>corporate a range of commercially<br />
viable and/or impact mitigat<strong>in</strong>g species.<br />
There are still economic and technical<br />
challenges to overcome before<br />
full-scale commercial production can<br />
take place; current f<strong>in</strong>d<strong>in</strong>gs po<strong>in</strong>t to<br />
<strong>the</strong> large-scale development of open<br />
ocean shellfish and f<strong>in</strong>fish farm<strong>in</strong>g <strong>in</strong><br />
New Zealand. Shellfish will be farmed<br />
<strong>in</strong> blocks but <strong>in</strong> low density. Farm expansion<br />
will be staged so that environmental<br />
assessments can be made as <strong>the</strong><br />
farm develops, provid<strong>in</strong>g scope for<br />
impact mitigation if necessary. Initial<br />
culture will focus on Greenshell mussels<br />
with a production goal from both<br />
sites of approximately 15,000 MT/year<br />
(33 million lb/year). Hatchery produced<br />
spat will likely become <strong>the</strong> dom<strong>in</strong>ant<br />
supplier to <strong>the</strong> open ocean farms <strong>in</strong><br />
<strong>the</strong> future. In addition, <strong>the</strong> potential<br />
foroysterandscallopisalsobe<strong>in</strong>gtested.<br />
Once fur<strong>the</strong>r work has taken place on<br />
<strong>the</strong>se two species, it is anticipated that<br />
<strong>the</strong>y will also be cultured at <strong>the</strong> offshore<br />
sites. F<strong>in</strong>ally, f<strong>in</strong>fish farm<strong>in</strong>g may be<br />
added if consent can be obta<strong>in</strong>ed to<br />
allow this farm<strong>in</strong>g practice to take<br />
place on <strong>the</strong> sites.<br />
Case Example 2: Mussel<br />
and Oyster Farm<strong>in</strong>g<br />
on <strong>the</strong> California Coast<br />
The open water production of<br />
bivalve shellfish off <strong>the</strong> coast of sou<strong>the</strong>rn<br />
California has a fairly long history,<br />
beg<strong>in</strong>n<strong>in</strong>g with <strong>the</strong> harvest of<br />
Mediterranean mussels by Ecomar<br />
Inc. from oil platforms <strong>in</strong> <strong>the</strong> Santa<br />
Barbara Channel <strong>in</strong> <strong>the</strong> 1970s. This<br />
example describes <strong>the</strong> operation of<br />
<strong>the</strong>SantaBarbaraMaricultureCo.<br />
The grower, Bernard Friedman, previously<br />
worked for Ecomar where he<br />
grew Pacific (C. gigas) andEastern<br />
(Crassostrea virg<strong>in</strong>ica) oysters and developed<br />
much of <strong>the</strong> methodology<br />
May/June 2010 Volume 44 Number 3 61
for grow<strong>in</strong>g oysters <strong>in</strong> <strong>the</strong> open ocean<br />
that is still <strong>in</strong> use today. The Santa<br />
Barbara Mariculture Co. was established<br />
on a site leased from <strong>the</strong> state<br />
<strong>in</strong> 2003 and now farms Pacific oysters<br />
and Mediterranean mussels.<br />
Site Description<br />
The shellfish farm is at a 28-ha<br />
(70-ac) site about 1.2 km (0.75 mile)<br />
off <strong>the</strong> Santa Barbara coast (Figure<br />
6). The farm currently has twelve<br />
137-m (450-ft) longl<strong>in</strong>es submerged<br />
at a depth of 6 m (20 ft) and runn<strong>in</strong>g<br />
parallel to shore <strong>in</strong> about 24 to 27 m<br />
(80–90 ft) of water. Pacific oysters<br />
are cultured <strong>in</strong> five-tier square lantern<br />
nets (Figure 7), and Mediterranean<br />
mussels are rope-cultured us<strong>in</strong>g New<br />
Zealand style culture technology. A<br />
10.5-m (35-ft) custom alum<strong>in</strong>um<br />
boat services <strong>the</strong> farm that lies about<br />
6.5 km (4 miles) from <strong>the</strong> harbor and<br />
takes 20 m<strong>in</strong> to commute (Figure 8).<br />
TheSantaBarbaraChannelhas<br />
water temperatures rang<strong>in</strong>g 10°C to<br />
FIGURE 6<br />
20°C (50°F to 70°F). Currents can be<br />
very strong at times mak<strong>in</strong>g it difficult<br />
to work <strong>the</strong> gear. W<strong>in</strong>ds are usually<br />
calm <strong>in</strong> <strong>the</strong> morn<strong>in</strong>g and blow 20 to<br />
Location of <strong>the</strong> Santa Barbara Mariculture Co., <strong>in</strong> Santa Barbara Channel, California.<br />
62 <strong>Mar<strong>in</strong>e</strong> Technology Society Journal<br />
FIGURE 7<br />
Five-tiered lantern net used for open water<br />
oyster culture. The ma<strong>in</strong> longl<strong>in</strong>e is shown<br />
with <strong>the</strong> hydraulically driven retrieval block.<br />
FIGURE 8<br />
Seeded mussel ropes be<strong>in</strong>g attached <strong>in</strong> a cont<strong>in</strong>uous<br />
loop to <strong>the</strong> ma<strong>in</strong> longl<strong>in</strong>e.<br />
40 km/h (10–20 knots) by <strong>the</strong> afternoon.<br />
Waves are relatively calm, but<br />
waters receive 0.5 to 1 m (2–3 ft)w<strong>in</strong>d<br />
chop regularly, 2 to 3 m (6–10 ft) swell<br />
on occasion. The site rarely experiences<br />
extreme conditions with 6-m<br />
(20-ft) swells and 110-km/h (60-knot)<br />
w<strong>in</strong>ds. An attempt is made to service<br />
<strong>the</strong> farm 2 to 4 days every week of <strong>the</strong><br />
year. Certification for shellfish harvest<strong>in</strong>g<br />
requires weekly shellfish samples to<br />
test for paralytic shellfish poison<strong>in</strong>g and<br />
amnesic shellfish poison<strong>in</strong>g (domoic<br />
acid). The water is tested for fecal coliforms<br />
monthly and after heavy ra<strong>in</strong>fall<br />
events.<br />
Farm Operations and Production<br />
Each 137-m longl<strong>in</strong>e is constructed<br />
of 25-mm (1-<strong>in</strong>ch)-diameter rope. No<br />
metal is used <strong>in</strong> any part of <strong>the</strong> system.<br />
The longl<strong>in</strong>es are designed to hang<br />
6 m below <strong>the</strong> surface by a series of<br />
floats and weights and are anchored
with concrete anchors designed to grip<br />
<strong>the</strong> ocean floor. Generally, new or replacement<br />
deployments are m<strong>in</strong>imal,<br />
and some longl<strong>in</strong>es have been <strong>in</strong><br />
place for 7 years.<br />
Mussel larvae and oyster seed are<br />
purchased from several hatcheries <strong>in</strong><br />
<strong>the</strong> Northwest U.S. Sett<strong>in</strong>g of mussel<br />
larvae on fuzzy rope <strong>in</strong> tanks and transfer<br />
out to <strong>the</strong> farm has proven most effective.<br />
Oyster seed exhibits excellent<br />
survival <strong>in</strong> <strong>the</strong> oceanic environment<br />
with mortalities usually because of<br />
<strong>the</strong> lack of proper handl<strong>in</strong>g or attention<br />
by <strong>the</strong> farmer.<br />
Each longl<strong>in</strong>e can hold up to<br />
6,800 kg (15,000 lb) of shellfish. As<br />
<strong>the</strong> shellfish grow, more submerged<br />
floatsareaddedto<strong>the</strong>longl<strong>in</strong>eto<br />
keep it balanced underwater. When<br />
<strong>the</strong> shellfish are ready to be harvested,<br />
<strong>the</strong> boat crew pulls <strong>the</strong> longl<strong>in</strong>e to <strong>the</strong><br />
surface with a hydraulic l<strong>in</strong>e hauler and<br />
custom crane. The oyster nets are<br />
mechanically swung <strong>in</strong>to <strong>the</strong> boat.<br />
The mussel ropes are also mechanically<br />
pulled <strong>in</strong>to <strong>the</strong> boat over a wheel<br />
attached to <strong>the</strong> side of <strong>the</strong> boat. The<br />
mussels are <strong>the</strong>n stripped from <strong>the</strong><br />
rope and declumped with a mach<strong>in</strong>e.<br />
The harvest of oysters from <strong>the</strong> nets<br />
is a more labor-<strong>in</strong>tensive operation<br />
with little mechanical enhancements.<br />
Productivity is excellent. The nearshore<br />
oceanic environment <strong>in</strong> <strong>the</strong> Santa<br />
Barbara Channel has proven to be very<br />
good for shellfish growth and health.<br />
The animals thrive with good yields<br />
and high condition <strong>in</strong>dexes. They<br />
usually outcompete most biofoul<strong>in</strong>g;<br />
however, oyster nets will foul if left<br />
unattended. The preferred culture<br />
method is to rotate <strong>the</strong> oysters through<br />
a succession of nets. The ropes and<br />
buoys also need regular clean<strong>in</strong>g.<br />
Oysters and mussels are brought<br />
to market from a 6-mm (0.25-<strong>in</strong>ch)<br />
seed to a 100-mm (4-<strong>in</strong>ch) seed <strong>in</strong><br />
10 months. These shellfish are considered<br />
premium product and sell very<br />
well <strong>in</strong> <strong>the</strong> market.<br />
O<strong>the</strong>r Ecological Observations<br />
The relatively low culture densities<br />
and strong water currents make it hard<br />
to gauge any effects on primary productivity.<br />
Shellfish are grown over a<br />
sand bottom, and <strong>the</strong>re is no evidence<br />
of shell accumulations under or adjacent<br />
to <strong>the</strong> longl<strong>in</strong>es. Strong currents<br />
probably transport any shell-fall from<br />
<strong>the</strong> farm.<br />
Div<strong>in</strong>gduckssuchasscoters<br />
(Melanitta spp.) have proven to be important<br />
predators. They can dive to<br />
about 10 m (30 ft) and will eat any<br />
musselslessthan50mm(2<strong>in</strong>ches)<br />
<strong>in</strong> shell length. The ducks migrate<br />
through <strong>the</strong> Santa Barbara area February<br />
and will loiter at <strong>the</strong> farm to feed on<br />
<strong>the</strong> young shellfish. Lower<strong>in</strong>g <strong>the</strong> mussel<br />
l<strong>in</strong>es to 15 m (50 ft) placed <strong>the</strong>m<br />
below <strong>the</strong> div<strong>in</strong>g depth of <strong>the</strong> ducks<br />
and largely elim<strong>in</strong>ated mussel predator<br />
losses. Growth rates were slightly reduced,<br />
and <strong>the</strong> mussels reached market<br />
size a few months later than normal.<br />
Whales, seals, and dolph<strong>in</strong>s also travel<br />
through <strong>the</strong> farm with no <strong>in</strong>teractions<br />
and appear to be nei<strong>the</strong>r attracted to<br />
<strong>the</strong> farm nor repelled.<br />
The Future of Open Ocean Shellfish<br />
<strong>Aquaculture</strong> <strong>in</strong> <strong>the</strong> Case Area<br />
The farm operator believes <strong>the</strong><br />
rear<strong>in</strong>g of shellfish <strong>in</strong> <strong>the</strong> nearshore<br />
oceanic environment of <strong>the</strong> Santa<br />
Barbara Channel has great potential;<br />
however, <strong>the</strong>re are several constra<strong>in</strong>ts<br />
slow<strong>in</strong>g down production at <strong>the</strong> moment.<br />
One is that only about 450 kg<br />
(1,000 lb) of mussels or 3,000 oysters<br />
can be harvested a day. The process of<br />
wash<strong>in</strong>g and bagg<strong>in</strong>g <strong>the</strong> shellfish for<br />
market is completed on <strong>the</strong> boat, and<br />
when <strong>the</strong> boat reaches <strong>the</strong> dock, <strong>the</strong><br />
shellfish are sold to distributors. This<br />
keeps overall operat<strong>in</strong>g cost down<br />
and <strong>in</strong>creases shelf life <strong>in</strong> <strong>the</strong> market<br />
but limits production volume.<br />
The rear<strong>in</strong>g of shellfish <strong>in</strong> <strong>the</strong> Santa<br />
Barbara area is considered beneficial by<br />
local environmental groups. This has<br />
been made possible by <strong>the</strong> grower engag<strong>in</strong>g<br />
<strong>in</strong> proactive <strong>in</strong>teractions with<br />
<strong>the</strong> local community to ga<strong>in</strong> social<br />
and environmental acceptance of his<br />
offshore farm practices. Santa Barbara<br />
Mariculture’s strategy and philosophy<br />
for future growth is to <strong>in</strong>vest heavily<br />
<strong>in</strong> technology, but <strong>in</strong> small and easily<br />
manageable steps. This requires relatively<br />
light weight boats, gear, and mach<strong>in</strong>ery<br />
with low operat<strong>in</strong>g costs. The<br />
emphasis is on speed, mobility, and<br />
flexibility to overcome many of <strong>the</strong> unknown<br />
challenges of open ocean farm<strong>in</strong>g.<br />
Santa Barbara Mariculture does<br />
plan to expand its farm<strong>in</strong>g operations<br />
to o<strong>the</strong>r species and will do so when<br />
opportunities present <strong>the</strong>mselves.<br />
Case Example 3: Rock<br />
Scallop Culture Trials<br />
<strong>in</strong> <strong>the</strong> Pacific Northwest<br />
In 2000–2001, research was carried<br />
out <strong>in</strong> a jo<strong>in</strong>t effort by <strong>the</strong> Wash<strong>in</strong>gton<br />
State–based firms, <strong>the</strong> Taylor<br />
Resources, <strong>the</strong> Makah Indian Tribe,<br />
and <strong>the</strong> Ocean Spar Technologies, to<br />
adapt available offshore f<strong>in</strong>fish culture<br />
technology to shellfish aquaculture. A<br />
platform structure was used <strong>in</strong> a pilotscale<br />
experiment for grow<strong>in</strong>g purpleh<strong>in</strong>ged<br />
rock scallops Crassadoma<br />
giganteus (formally H<strong>in</strong>nites multirugosus).<br />
The system was designed to withstand<br />
high-energy ocean waves and current<br />
conditions and represented a modification<br />
of exist<strong>in</strong>g Ocean Spar Technolog<br />
buoy technology currently used <strong>in</strong> state<br />
of <strong>the</strong> art fish pens. It is a marked departure<br />
from <strong>the</strong> designs of <strong>the</strong> open water<br />
shellfish culture systems described <strong>in</strong><br />
May/June 2010 Volume 44 Number 3 63
<strong>the</strong> o<strong>the</strong>r two case examples. A detailed<br />
f<strong>in</strong>al report was prepared for this project<br />
<strong>in</strong> 2003 (Davis, 2003). This case<br />
example summarizes <strong>the</strong> f<strong>in</strong>d<strong>in</strong>gs and<br />
conclusions from that report.<br />
Pilot Farm Design and Setup<br />
The test site was <strong>in</strong> <strong>the</strong> Strait of<br />
Juan de Fuca <strong>in</strong> northwest Wash<strong>in</strong>gton,<br />
approximately 2 km (1 0.25 mile)<br />
offshore and 3 km (1.75 miles) south<br />
of <strong>the</strong> nearest vessel access (Figure 9).<br />
The site was subject to tidal flows, prevail<strong>in</strong>g<br />
ocean waves, and swell from<br />
<strong>the</strong> nor<strong>the</strong>ast Pacific Ocean. Currents<br />
ranged from 0.0 knot at slack tide to<br />
a maximum of 1 m/sec (2.0 knots).<br />
FIGURE 9<br />
The primary component of <strong>the</strong> culture<br />
system was <strong>the</strong> submersible Spar<br />
buoy. This platform was selected to<br />
provide a stable platform for experiment<strong>in</strong>g<br />
with a variety of rigid grow<strong>in</strong>g<br />
surfaces on which to culture rock scallops.<br />
Rock scallops were thought to be<br />
well suited for exposed, higher energy<br />
sites because of <strong>the</strong>ir biological need to<br />
attach to a solid structure.<br />
The Spar buoy was a 0.9-m<br />
(36-<strong>in</strong>ch) diameter by 12 m (40 ft)<br />
long steel cyl<st