The Sea Grant programs of the Northeast are leading the effort to introduce open ocean aquiculture to North America, hoping to help build an industry to augment fish stocks that have declined drastically and to meet a steadily increasing consumer demand for sea food products. Support has come from the National Sea Grant College Program as part of a regional project to develop commercially viable groundfish aquiculture industries in the Northeast and from the National Marine Fisheries Service (NMFS). 

A year ago, the University of Maine/University of New Hampshire Sea Grant College Program, UNH Cooperative Extension (UNHCE), NMFS, and the Massachusetts Institute of Technology Sea Grant College Program sponsored the first international conference on open ocean aquiculture. Over 200 people gathered in Portland, Maine, for three-and-a-half days to take in more than 30 presentations. These included formal papers, panel discussions, poster sessions, and audience question-and-answer exchanges. Field trips were also offered, with some participants braving foul weather to visit the GreatBay Aquafarm in Newington, N.H., and UNH's Ocean Engineering facilities in Durham. A visit to a UNH cod pen project in the Gulf of Maine had to be canceled because of heavy seas. 

Conference chairman Rollie Barnaby, UNHCE/Sea Grant educator, explained that the goal of the event was to gather people from around the world in order to find out "what we know, what we don't know, and what we need to know" to move aquiculture to the open ocean. Barnaby believes that the development of marine aquiculture is dependent on identifying offshore grow-out areas because the possibility of finding nearshore, protected sites for grow-out cages on most of the United States coastline is very slim, for a variety of reasons. 

The conference targeted aquaculturists, fishermen, marine biologists, ocean engineers, community development specialists, environmental regulators and policy makers, natural resource economists, students, planners, businessmen, and investors. And they came from the East and West coasts of the United States (including Hawaii), Canada, Norway, Sweden, Ireland, England, Portugal, Italy, Russia, Israel, Japan, and New Zealand. 

Hunt Howell, UNH zoology professor, described how landings from the North Atlantic trawl fishery have declined severely over the past 10 years (500 million pounds in 1983 to only 219 million pounds in 1992), while seafood consumption in the U.S. has increased and is projected to continue to do so (reaching 20 pounds per capita by the year 2000). 

Howell believes that aquiculture is the most promising alternative for meeting this increased demand and that cod,Gadus morhua, is one of the most prominent candidate species for commercial aquiculture in the Northeast. 

"We need to overcome the lack of information on brood stock management, larval rearing systems, diets for larvae and juveniles, and appropriate grow-out systems," said Howell. Engineers designing submersible net-pen systems must understand the biological consequences of fish changing depth as the pen is raised or lowered. 

Cod have an internal gas-filled swim bladder, used primarily to maintain neutral buoyancy. If the pen is raised too rapidly, the bladder could rupture and other internal organs could be damaged. If the pen is lowered too rapidly, the fish may lose buoyancy. The rate at which fish are able to adjust is critical. The time required to raise a pen could extend over several hours. This would be very costly. Water temperature changes with depth, and even small variations can have considerable physiological effects.  

Limited and accidentally interrupted net-pen experiments at UNH's Coastal Marine Lab and at a site near the Isles of Shoals last summer determined that cod raised and lowered too fast for their swim bladders to adapt showed no significant differences in length or weight from those raised and lowered at appropriate speeds. Despite some over-inflated swim bladders, no mortalities were observed. "Much more study needs to be done," Howell pointed out, but this very preliminary study and a similar one that followed suggest that the growth and survival of the fish are acceptable. 

Biologists at the University of Maine (Linda Kling) and at the University of Rhode Island (Terry Bradley and Lawrence Buckley) are studying larval rearing systems and brood stock management. Maintaining genetic diversity is a major problem. 

A team of mechanical engineers from UNH who have worked closely Howell, with UNH professors Barbaros Celikkol and Godfrey Savage, are developing an open ocean fish cage that will cost less than $1 per cubic foot of pen space. Celikkol's presentation focused on their investigation of the survivability of a submersible version at depth. They designed and built three 1:16 scale models. Their design criteria included economics, safety, corrosion and fatigue, mooring systems, size, ease of construction, installation, cleaning, and harvesting. Next they subjected the models to wave spectra at Heriot-Watt University in Edinburgh, Scotland, in the Department of Civil and Offshore Engineering's 1 meter deep model wave basin. 

The team proposed submersible cages as an alternative to surface models, which have already proven unsuccessful. (Greater wave forces encountered there stress the fish.) They base their conclusion on their realization that 95 percent of the wave energy is lost at relatively small depths. Needing a method of quantifying this assertion, they have written software enabling them to make projections of motion and force from the test depths to much greater ones and in more extreme sea conditions. 
 
These tests, along with a test of UNH's first cod cage at the Isles of Shoals in the fall of 1995, have proven that cage shape should be determined by emphasizing ease of installation, servicing, harvesting, and safety, according to the researchers. Savage pointed out that the work started as an undergraduate project and owes much to the students who helped design and build the cages. 

Two cages were tested last summer just southeast of the Shoals' White Island. Twice a week, fishermen took turns feeding the fish 10 pounds of herring frozen in a block of ice that released the food as it melted. The goal is to start with 1-pound hatchery-grown juveniles and grow them to 5 or 6 pounds in about four months. 

Another team of mechanical engineers from UNH employed the finite element modeling method to study and report on the dynamic response of offshore net-pens to complex current and wave loading. Assistant professor. Michael Gosz (now at the Illinois Institute of Technology), professors Rob Swift and Celikkol, and graduate student Ken Kestler hope to spare the commercial open ocean aquiculture industry much of the expense and time required by the trial-and-error method of designing and testing prototypes of offshore net-pens. UNH resource economics and development assistant professor Rob Robertson, professor Bruce Lindsay, and graduate student Daniel Gardoqui are also part of the regional finfish aquiculture project. At the conference they presented the results of their research planning exercise in "scoping" the potential social impacts of open ocean aquiculture. Scoping (preliminary assessment) is a first stage of the social impact assessment (SIA) process required by the National Environmental Policy Act, the Magnuson Fishery Conservation and Management Act, and the Outer Continental Shelf Lands Act. The purpose of an SIA is to optimize decisions having environmental implications by facilitating effective use of scarce human and fiscal resources. 

The goals of this research planning exercise were to enlist the assistance of experts in identifying key stakeholder groups that could inhibit or enhance the development of open ocean aquiculture and to prioritize the critical issues and concerns facing the successful development of the industry. The preliminary findings suggest that commercial fishermen are critically important stakeholders. The researchers identified four major types of concerns associated with the development of open ocean aquiculture: environmental issues, conflicts over use, legal concerns, and technical feasibility. 

Robertson, Lindsay, and Gardoqui concluded that their results point to the need for a credible mechanism for greater public involvement in the project planning and implementation process. Their future work with the regional project will be aimed at developing just that for the entrepreneurs, engineers, biologists, and others striving to develop open ocean aquiculture. 

James Anderson, University of Rhode Island resource economics professor, spoke at the conference about the implications for offshore culture of market trends for Maine's pen-raised salmon and steelhead trout industry (the largest aquiculture sector in the Northeast, valued at nearly $53 million in 1995). He warned that offshore aquaculturists should make sure that their costs are lower than those of existing types of operations and that evaluation of the costs and risks of open ocean aquiculture demands greater attention than he has found in many business plans. 
 

Several conference presenters examined the legal and regulatory aspects of the development of open ocean aquiculture. Alison Rieser, director of the Marine Law Institute of the University of Maine School of Law in Portland, described some of the important attributes of an effective legal framework for ocean aquiculture and addressed whether federal agencies can provide these under current laws. She reviewed key provisions of proposed federal legislation for management of aquiculture in the 200-mile Exclusive Economic Zone (EEZ) and sketched out an alternative system of state-based management with federal oversight and coordination. 

In a related effort, Cliff Goudey, MIT Sea Grant Marine Advisory leader, and Ronald Smolowitz of Coonamessett Farm in East Falmouth, Mass., have established a 9-square-mile site for the experimental culture of the giant sea scallop in the EEZ south of Martha's Vineyard, Mass. Along with Dale Leavitt, Woods Hole Oceanographic Institution Sea Grant fisheries and aquiculture specialist, and others, their goal is to develop sustainable production practices for the New England scallop industry and promote economic growth. They are evaluating, both biologically and economically, a variety of methods of contained and on-bottom culture methods. The site is the first project to have been granted exclusive use of an area of the EEZ for aquiculture purposes. It is also the first site to involve large-scale suspended containment systems designed for full exposure to the rigors of the northwest Atlantic Ocean. Their presentation described in detail the permitting and regulatory process. 

As noted earlier, open ocean aquiculture is being practiced successfully at several sites around the world. The Portland conference gave Americans interested in the field a chance to learn about the many techniques being used and to make contacts with those involved in the field internationally. It also helped launch an era of international cooperation in the further development of open ocean aquiculture. In April 1997, a second conference sponsored in part by Sea Grant brought a large number of people interested in the field to Hawaii for a "Pacific" version of the Portland conference, and in September, UNH and Sea Grant will host a symposium where a number of American and Japanese aquaculturists will have an opportunity to discuss their work and possible collaborations.   

Marie Polk is an editor/information specialist with the UM/UNH Sea Grant College Program.