February 15-18, 2009 Washington State Convention Center Seattle ...

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OVERCOMING OPERATIONAL CHALLENGES IN OFFSHORE FISH FARMING
R. Chris Stock*, Glenn Flanders and Steve Page
Ocean Farm Technologies
114 Higgins Rd. N.
Searsmont ME, 04973 USA
cstock@oceanfarmtech.com
Deep sea, open ocean aquaculture has become a reality only in very recent history. Modern engineering and technological advances
have helped create solutions to many challenges that were previously considered impediments to the success of offshore
farming. At the same time innovative new pen designs created for offshore fish farming have provided solutions to some more
traditional aquaculture problems.
Open ocean aquaculture can eliminate or reduce many of the obvious shortcomings of present coastal fish farms such as excess
waste deposition, disease outbreaks and common space use conflicts but it has also produced some unexpected solutions to
other equally important challenges. The success of newer more practical submersible pens can be attributed to their designs
which have taken into account the operational deficiencies of floating cages and near shore aquaculture.
Submersible pens such as the Aquapod easily incorporate rigid mesh materials like marine grade galvanized steel which were
previously difficult or impossible to apply to floating pens. These materials have proven impenetrable to predators and can
eliminate escapes which have proven to be a perennial challenge to conventional net pen fish farmers. Another disadvantage to
traditional nets is that handling them for maintenance purposes is a laborious and time consuming process. Some submersible
offshore pens can be surfaced and rotated in their moorings to allow for inspection, repair and cleaning above the waterline
which dramatically cuts costs, reduces dive times and improves safety.
Submerging these pens not only shelters them from storms and foul weather but can also allow the farmer to take advantage of
favorable environmental conditions not found at the surface. Production at depth can reduce fouling and often provides cooler
more consistent temperatures which may benefit particular species, such as cod.
Open ocean aquaculture not only provides optimal conditions for the health and growth of a crop, but it is an ideal solution to
many traditional operating problems. Present and emerging technologies will continually improve offshore fish farming and
eventually it will become a predominant means of aquaculture production.