NOAA RESEARCH HARVESTS A SUSTAINABLE WAY TO FARM THE DEEP BLUE
February 18, 2005 — In June 2004, divers broke the surface one mile south of New Hampshire’s White Island, holding bright yellow bags filled with healthy Atlantic Halibut. They handed these to their colleagues on the Fishing Vessel Rock and Roll and dove under for more. When they were finished, they had harvested one-and-a-half tons of fish — perhaps the largest single haul of this once common groundfish in the Gulf of Maine since the 1950s.
These fish are the first halibut ever grown offshore in deep water cages, an accomplishment achieved due to the foresight of NOAA and the collective ingenuity of marine biologists, engineers, ecologists, educators and fishermen. They are also the first finfish crop of the Open Ocean Aquaculture Demonstration Project (also known as OOA), a partnership between NOAA and the University of New Hampshire. The OOA was established in 1997 to develop the research and technology necessary to establish an economically viable, socially compatible and environmentally responsible offshore aquaculture industry.
“We set out to test whether we could raise finfish and shellfish offshore, in the extreme environments of the Gulf of Maine,” explains Richard Langan, director of the OOA and the NOAA/UNH Cooperative Institute for New England Mariculture and Fisheries (also known as CINEMAR). “Today we know we can — our offshore mussel culture operation has given rise to two commercial farms, and this year we will harvest the first crops of deep sea-raised North Atlantic cod and haddock.”
The OOA Demonstration Project is part of CINEMAR, a joint institute between UNH and NOAA. CINEMAR provides regional leadership and integration for research, development, education and outreach to support the use, management and preservation of New England fisheries.
on the Open Ocean
are no small mistakes on the open ocean; the high-energy conditions of
the North Atlantic have a way of magnifying the tiniest oversight,”
said Dave Fredriksson, a UNH assistant research professor of mechanical
engineering. “Everything we design is subject to the most stringent
mathematical and computer modeling, and we have an operations crew who
groundtruths all of our structures and operational designs — firsthand
experience is a valuable data point.”
The NOAA Small Business Innovation Research Program (also known as SBIR) has helped engineers facilitate the transfer of the technologies they develop. SBIR grants have partnered the OOA with Net Systems, Inc., to build and test a commercial scale 20-ton capacity automated feeder; with E Paint, Inc., to develop nontoxic antifouling coatings to prevent the attachment of colonizing organisms to aquaculture structures; and with JPS Industries to design a 5,000 cubic meter cage that will maximize carrying capacity while minimizing manufacturing cost.
“All of the technology on this project is developed with an eye to how cost-effective and practical it will be for the aquaculture industry to utilize,” says Fredriksson. “That means we have to be creative about the components we use, and how we put them together. The needs of the end users keep us on the right track.”
England Fishermen are Mussel Bound
“We need alternatives in the face of changing fishing restrictions and the fact that our fisheries are not an infinite resource,” says Andy Lang, an independent fisherman who is farming mussels under the permits. “This is a wide-open opportunity.”
operations that use floating rafts or surface lines, these new farms are
located nearly three miles offshore, and the mussels are grown from submerged
longlines — out of sight and safely away from boat traffic. From
the surface, passersby will only see two pairs of buoys, bobbing 600 feet
apart. (Click on NOAA image below right for a larger view
“New England’s coastal harbors and bays are already overcrowded,” says Forbes Horton, OOA shellfish production manager and fishing vessel captain. “We’ve been able to offer fishermen an economic opportunity with no impact on the environment, affordable startup costs, and very little conflict with established activities.”
When farmed offshore, far from pollution sources, blue mussels (Mytilis edulis) are a healthy and nutritious source of protein. To escape the Gulf of Maine’s currents, waves and weather, growing ropes are suspended from a long line submerged 40 feet below the surface. The site, determined by working with the commercial and recreational fishermen, was chosen to avoid the hard bottom (i.e., boulders and ledges recreational fishermen and lobstermen depend on for their catch).
“There has been no measurable environmental impact,” says Ray Grizzle, a UNH benthic ecologist who studies organisms that live within and on the ocean floor. Grizzle and his colleagues take the environmental pulse of this ecosystem four times each year. Box core samples and video footage taken of the bottom gauge the abundance and diversity of the animals that live on and in the ocean floor. Samples of the sediment are evaluated for changes in organic content.
The water column is continuously sampled by an environmental monitoring buoy, developed and maintained by engineers from UNH and Woods Hole Oceanographic Institution. The buoy’s instruments measure waves, water temperature, salinity, dissolved oxygen, fluorescence and turbidity — all of these parameters have been consistent since testing began.
Given the high energy environment of the Gulf of Maine, where prevailing currents move huge volumes of water through the fish cages on a regular basis, OOA researchers have not been too surprised by these results.
“The extreme conditions that make open ocean aquaculture such an engineering challenge are the same ones that convinced us it could be a sustainable practice,” says Langan. “We will continue watching the environment very carefully as we scale up the operation to raise commercial-size populations of fish.”
By combining biotelemetry (the remote measurement of biologically relevant data, including behavioral, physiological, physical or environmental data) and video techniques, OOA researchers are also gathering data on cod behavior in a setting that approximates their natural habitat. To trace the cods’ movements, they rely on “pingers,” ultrasonic transmitters implanted in the fish. As the tagged cod swim and feed, their pingers emit high frequency “chirps” that are picked up by underwater microphones. The fish also wear external tags so the researchers can monitor them by video camera. By comparing this information to lab studies that calculate how much energy cod burn when they swim at different speeds, and to environmental data from the cage site, researchers are able to paint a picture of a cod’s life — how much food it needs in different conditions, what temperatures it thrives in and the type of environment it prefers.
“Biotelemetry is a powerful tool for learning about cod biology and developing smarter, cleaner methods of aquaculture,” says Hunt Howell, a UNH professor of zoology. “This information will help aquaculture farmers prevent over-feeding and reduce environmental impact, assist in the design of cages that fish can fully utilize, and help determine at what depth and temperature cod grow best.”
NOAA is proud
to participate in the CINEMAR effort, which supports one of NOAA's
primary mission goals — to protect, restore and manage the use
of coastal and ocean resources through ecosystem-based management.
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