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

RECIRCULATING AQUACULTURE SYSTEM FOR PILOT COMMERCIAL PRODUCTION
OF MARINE FINFISH IN NORTH CAROLINA: PRIVATE-PUBLIC PARTNERSHIP FOR
RESEARCH, EDUCATION AND TECHNOLOGY TRANSFER
Patrick M. Carroll*, Wade O. Watanabe, Thomas M. Losordo, Dennis P. DeLong, J.P. McCann, Glenn Hargett
and Shawn Longfellow
University of North Carolina Wilmington (UNCW)
Center for Marine Science
601 South College Rd.
Wilmington, NC 28403-5927 USA
carrollp@uncw.edu
An environmental education center (Riverworks at Sturgeon City) is under development in Jacksonville, NC. The center’s mission
is the adaptive reuse of a former waste water treatment plant that had discharged into Wilson Bay for more than 40 years
as a headquarters for restoring that habitat and educating citizens to avoid environmental mistakes made in the past. UNCW is
collaborating with the city of Jacksonville to retrofit facilities associated with this wastewater treatment plant for a pilot-scale
recirculating aquaculture system (RAS) for marine finfish and to demonstrate activities that link economic development with
environmental conservation and restoration. Under joint support by MARBIONC (Marine Biotechnology in North Carolina)
and the City of Jacksonville, a pilot RAS was designed by North Carolina State University (NCSU) and UNCW and assembled
on site. The RAS system consists of six 4.62 m-dia. fish culture tanks supported by state-of-the-art RAS components, including
a microscreen drum filter for solids removal, moving bed biofilters for conversion of ammonia to nitrate-nitrogen, foam fractionators
for removal of fine and dissolved organic particulates, ultraviolet sterilizers for disinfection of water, and a geotextile
tube system (“geotube”) for sequestration and management of solid wastes. The RAS is enclosed in an agricultural shelter and
is designed to conduct controlled, replicated studies on the production of high value marine finfish species such as southern
flounder (Paralichthys lethostigma) and black sea bass (Centropristis striata) at high stocking densities and to test economic
viability. In collaboration with a commercial partner (Blue Ocean Farms, LLC), a pilot commercial demonstration project was
recently initiated on site. The commercial partner is operating the pilot RAS as a business, while receiving hands-on training in
cooperation with a multi-disciplinary team from UNCW and NCSU. The project involves undergraduate and graduate students
from local colleges in fish production activities and integrates UNCW’s goals of research, education and technology transfer
through direct cooperation with the commercial end user. A unique aspect of this near commercial scale RAS is that it will
integrate the culture of marine finfish with the culture of microalgae and bivalves in municipal waste drying beds adjacent to the
fish barn. Research will evaluate the use of nutrient-laden effluent from the RAS as a nutritive base to produce microalgae (e.g.
Chaetocerous gracilis), which will then be used to support the substantial feed demands of marine bivalves, e.g. Eastern oyster
(Crassostrea virginica). Oysters produced in this polyculture system can then be utilized for outplanting into Wilson Bay
where they may continue to reduce nutrient levels and improve water quality. Converting expensive nitrogen and phosphorus
into a valuable product will increase profit for the fish farmer, diversify production and reduce pollution.
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