In a millennium in which world population is growing by a billion mouths per decade and fisheries are severely depleted, it might seem that only miracles could feed our multitudes. Even the wisdom of ancient proverbs that would have us teach a person to fish in order to feed himself for a lifetime will not suffice. Scientists, entrepreneurs, fishermen, and others are turning to farming fish in the open ocean to avert the biological and socioeconomic consequences of threatened fisheries.

Inspired by successes in the Eastern Hemisphere, and more recently in Peru, Canada, and along both U.S. coasts, the University of New Hampshire (UNH), with the help of National Sea Grant College Program initiatives, is growing an open-ocean aquaculture demonstration project. Involving researchers, outreach specialists, commercial fishermen, aquaculturists, and educators, the project will provide a commercial-scale test site for methods developed through the research of the Northeast Sea Grant programs.

Top end of the center spar of the Sea Station net-pen being assembled at the N.H. Port Authority in Portsmouth.  Engineers from Ocean Spar Technologies and UNH's Center for Ocean Engineering are attaching top stay lines before the crane hoists the spar into position in the water.  Photo by Doug Prince, UNH CIS.

Ann Bucklin, UNH Sea Grant director, and Hunt Howell, UNH Coastal Marine Laboratory director, are members of a team of scientists and engineers that oversees the project. Bucklin and Howell, both zoology professors, report that great interest in raising several marine species in New England, both for consumption and for stock enhancement, has resulted in dozens of research projects on raising finfish, shellfish, and seaweeds. Related projects include building hatcheries, coordinating conferences and workshops, and even orchestrating pilot-scale releases.

Siting aquaculture ventures in New England is problematic, Bucklin and Howell explain, because coastal property is expensive and inshore waters are already heavily used for fishing and recreation. Therefore, some of the region’s aquaculture growth has to occur in exposed open-ocean sites. Such sites present new challenges, and before open-ocean aquaculture can become a reality, investors and commercial ventures must have reasonable assurance that the practice is feasible—biologically, technologically, economically, and socially.

Scientists involved with the UNH project, which will raise both finfish and shellfish, have selected a site near the Isles of Shoals, a mile south of White Island. To establish partnerships and prevent user conflicts, the team discussed the location with the Portsmouth Fisherman’s Cooperative (PFC), Inc.

Through monthly cruises aboard UNH’s RV Gulf Challenger, Frank Bub, UNH research scientist and project site-selection team member, and John Lund, physical oceanography master’s candidate, assessed the meteorology and physical oceanography of the site and collected baseline data. They also designed and built the permanent oceanographic buoy deployed during the winter of 1999 for use throughout the project.

Rob Swift and Barbaros Celikkol, UNH mechanical engineering professors, and Dave Frederiksson, engineering design doctoral candidate, built and tested scale models of commercially produced net pens. They examined drag in simulated environmental conditions, developing design loads and collecting data to validate ongoing computer modeling. Initially, the project will use two of Seattle-based Ocean Spar Technologies’ "Sea Station" cages.

UNH engineers have also investigated the overall dynamic behavior of net pen/mooring systems using a UNH-developed program that handles the very large displacements that accompany motion of fish cage systems in the ocean. Igor Tsukrov, mechanical engineering professor, and his colleagues have used it to model forces the mooring system will undergo.

Hoping to hasten the development of open-ocean aquaculture in New Hampshire, the researchers applied for the same state and federal commercial permits required of any new aquaculture venture in the state. At a preapplication meeting in January 1999, the regulatory community expressed concern about the potential for entanglements with endangered marine mammals and turtles and about conflicts with commercial fishermen. In response, the applicants met with the National Marine Fisheries Service (NMFS) and the New England Aquarium (NEA) regarding endangered species and with N.H. Fish and Game and commercial fishermen regarding conflicts. The outcome of these discussions was minor changes in the site location and in the culture technology for shellfish.

Concerns about impacts on marine mammals generated a study of acoustic strategies for solving problems caused by marine mammal encounters with fishing gear. Ken Baldwin, mechanical engineering professor and director of UNH’s Center for Ocean Engineering, and Scott Kraus, research director of the NEA’s Edgerton Research Laboratory, developed an acoustic model to provide insight into how sound is propagated and how characteristics of sound, such as volume, differ from "zones of influence," including ambient sounds and the range of sound to which an animal is sensitive.

Mammal vocalizations for communication, echolocation, and reproductive display must be considered so that mitigation strategies for one species do not displace others, caution Baldwin and Kraus. Also, harmful sound levels must be clearly defined. Such information will help researchers develop species-specific acoustic alarms for offshore aquaculture.

As soon as permits arrived, Swift, Celikkol, project engineer Paul Lavoie, and UNH ocean engineering graduate students installed the mooring grid that will anchor the cages to the sea floor. The system must hold fast in any sea conditions and must allow divers to connect and disconnect cages in less than 30 meters of water.

Species Selection

Summer flounder (Paralichthys dentatus) will be the first finfish species to inhabit the new grow-out cages. Individuals involved in aquaculture throughout New England selected summer flounder based on experience with the species, technology available in the region, and lab and/or hatchery space. Species tolerance of the region’s typical ocean temperatures (about 0° to 18° C) and a market value high enough to favor financial success were also major factors.

GreatBay Aquafarms, a commercial hatchery in New Hampshire and a partner in the open-ocean aquaculture project, collaborated with Howell and other UNH faculty to begin production of 6,000 juveniles in February 1998 with broodstock spawning. When fish stocking began in June 1999, GreatBay Aquafarms President George Nardi, Howell, and the UNH Veterinary Diagnostic Lab staff set up a health surveillance program. Vaccination for Vibrio anguillarum and V. ordalli, virology testing, and bimonthly tissue and bacteriologic exams began the health monitoring, which will continue in the net-pens.

The researchers are working to control the microbial ecology during early larval rearing in order to increase survival and limit pathogens in the culture environment and larval gut. They plan also to identify genetically superior broodstock by tracking the performance of individual families raised in a common environment.

Scrutiny of virtually every aspect of flounder culture—natural spawning versus hormonal inducement, larval and juvenile stocking densities, feed preferences, protein content of weaning diets, growth performance, use of recirculating seawater systems, wastewater characterization and effluent treatment, and thermal engineering (to capture a utility’s waste heat for heating seawater and air)—has brought a host of institutions into a cooperative funding arrangement for this project. In addition to Maine/New Hampshire Sea Grant and GreatBay Aquafarms, NMFS, the Northeast Regional Aquaculture Center, the N.H. Industrial Research Center, and the Electric Power Research Institute (EPRI) are contributing to these studies.

Two collaborators, GreatBay Aquafarms and EPRI, have developed a commercial-scale grow-out demonstration system to evaluate biofilter performance in recirculating life-support systems. The two entities have also worked together to engineer a land-based tank farm for assessing the effects of stocking density on biofilter performance and for comparing operating costs.

The blue mussel (Mytilus edulis) will be the first shellfish species grown by the project. Mussel aquaculturist Carter Newell of Great Eastern Mussel Farms (GEMF), Inc., in Maine, and John Bonardelli, director general for mariculture of G.R.T. Aqua-Technologies Ltd. of Québec, are project advisors. To ensure success for this year’s spat collection and grow-out effort, project investigators deployed lines in the water column at five sites selected about a year ago.

Of these sites, Fort Point in Newcastle, N.H., saw the densest settlement. UNH investigators, assisted by GEMF, undertook a field study to determine optimal times and places for collection and to correlate these with environmental features. They deployed 1,600 feet of seed-collection rope for two months and monitored weekly for growth and settlement density. Then they analyzed biweekly water samples for algae concentration, temperature, and salinity—and established a current velocity profile for a full tidal cycle. Later they will study marine mammal interaction with the gear.

UNH Sea Grant Extension Educator Rollie Barnaby is responsible for much of the demonstration project’s education and outreach component. He has hosted workshops in which Bonardelli described his suspension culture techniques and Walter Paul explained the requirements suspended culture systems need to survive wave and current forces in the open ocean. Paul is applied ocean physics and engineering senior engineer at the Woods Hole Oceanographic Institution (WHOI). Future plans range from training workshops and videos to site visits for media and decision-makers as well as direct outreach to fishermen, excursion boat owner, and other interested parties.

Nearshore Impacts

University of Maine (UM) researchers have been working over the past decade to develop computer modeling techniques to improve site selection and monitoring for commercial salmon net-pen aquaculture in Maine. Supported in part by NMFS, NOAA, and the UM School of Marine Sciences, graduate student Robert Dudley; his advisor Vijay Panchang, UM civil engineering professor; and mussel aquaculturist Newell have developed a mathematical modeling package called the Aquaculture Waste Transport Simulator (AWATS).

AWATS can be used to estimate the dispersal of net-pen wastes in a coastal environment with varying currents and wave-induced velocities. Use of AWATS at several coastal Maine sites selected by the Maine Department of Environmental Protection has confirmed the value of its versatility for regulatory use.

The researchers used fieldwork data from pens in Cobscook and Toothacher Bays in tuning their model. They stress that while net-pen aquaculture wastes affect coastal waters, the degree to which they do so depends on a multitude of conditions. These include current speed, water depth, vorticity, wind, seasonal effects, the presence of other operations, and waste transport mechanisms such as settling, resuspension, and decay.

Comprehensive modeling of these many factors successfully assessed the impact of the Cobscook and Toothacher Bay operations. The engineers report that more work needs to be done on modeling factors affecting resuspension. They also plan to create a modeling package for use by regulators.

Projects in the other New England states complement the Maine/New Hampshire open-ocean aquaculture research. Cliff Goudey, director of MIT Sea Grant’s Center for Fisheries Engineering Research (CFER), has been working with colleagues and the industry to develop open-ocean containment systems. Taking advantage of modeling capabilities at the Navy’s David Taylor Model Basin in Bethesda, Md., the researchers have performed industry-sponsored tests of systems in currents and waves, reducing the risks associated with prototype installations.

Model tests of MIT’s Ocean Drifter pen have been completed and operational modeling and prototype design are under way. The Ocean Drifter is a large, unmoored cage for use in ocean basins or in coastal current gyres. It is commercially and environmentally attractive because site permitting and effluent impacts are essentially eliminated.

Goudey and his colleagues are also developing cost-effective recirculating technologies for research and commercial applications. In addition, CFER has established the Boston Harbor Marine Finfish Hatchery in the Charlestown Navy Yard. The hatchery promotes commercial development of haddock and tautog.

At WHOI, Marine Policy Center Research Associate Porter Hoagland and his colleagues are using a bioeconomic approach to study the potential of offshore mariculture. Applying financial business planning and risk assessment techniques to development of a model of offshore aquaculture economics, the researchers are investigating the economic viability of prospective operations in New England. The model will incorporate new information on construction requirements and biological growth processes in marine settings, the effects of engineering and biological uncertainties, the costs of regulatory compliance, and impacts of supply and demand in relevant product markets.

At the Marine Biological Laboratory in Woods Hole, Mass., Associate Scientist Alan Kuzirian and colleagues are working on a WHOI Sea Grant–funded project to identify genetic markers to help evaluate the success of bay scallop seeding programs. They hope to identify unique phenotypic markers for shell patterning that will be recognizable in the field and well-adapted to hatchery culture. After extracting DNA from each scallop’s mantle tissue, the researchers spawn the scallops, culture the larvae, and compare the two generations’ DNA. A year after seeding the larvae in the field, they hope to be able to distinguish the lab-raised scallops from the feral ones in the same location. In this way, they can track survival rates and recruitment patterns.

At the University of Rhode Island (URI), Joseph DeAlteris, fisheries, animal, and veterinary science professor, is exploring the development of appropriate technology for shellfish and finfish aquaculture, focusing on the behavior of animals held in captivity at high densities in both land- and sea-based systems. He is also working on advanced filtration technologies for closed systems.

David Bengtson, URI fisheries, animal, and veterinary science associate professor, is studying the aquaculture of marine fish species and is investigating new species for aquaculture in the Northeast. Bengtson has done a lot of work with artificial diets for cultured fish to address the challenge of maximizing growth while minimizing wastes. He says that high-quality artificial diets can alleviate water quality and disease problems, as well as eliminate the high cost of live feed.

At the University of Connecticut (UConn), Charles Yarish, evolutionary biology professor, is a co-principal investigator for a Sea Grant project to develop a commercially viable seaweed aquaculture industry in New England. One project, funded by several federal agencies in addition to Sea Grant, concerns mariculture of several Porphyra species from coastal New England and the Canadian Maritimes. Over 130 unialgal cultures have been established, and several strains of each have successfully completed their life cycles in culture. Cultures have been successfully established in bivalve shells, an important stage of the domestication process.

Working with Yarish and his UConn colleagues on this project are Arthur Mathieson, plant biology professor; Anita Klein, biochemistry and molecular biology associate professor; and Chris Neefus, plant biology associate professor, all at UNH. Joining them are Ira Levine, CEO of PhycoGen, Inc., (formerly Coastal Plantations International) of Portland, Maine; Ian Davison, UM marine science and biology professor and UM Sea Grant interim director; and Don Cheney, Northeastern University biology associate professor. PhycoGen initiated commercial cultivation of the red alga called nori in Cobscook Bay, Maine, in 1991 as well as a pilot bioremediation project with a nori-salmon integrated polyculture system.

As we face exploding populations and fisheries less bountiful than once imagined, Sea Grant may not be able to work miracles—but it can do more than teach someone to fish. We can teach people to raise and sustain this valuable resource.