Thanks to a demonstration project at University of New Hampshire, funded by a grant from NOAA, fishermen who need to find alternative part-time work that will keep them on the water have another option in sight: submerged open ocean longline mussel farming.
Researchers at UNH, working with fishermen from the Portsmouth Fishermen’s Co-op, have labored since 1999 to get the bugs out of a new concept in shellfish and fish aquaculture: open ocean submerged pens for growing fish and submerged open ocean longlines for shellfish culture. Although other countries are utilizing open ocean fish pens and longline operations and some have submerged longlines near shore, none have developed a successful technique for submerged open ocean aquaculture, which has less visual impact and does not interfere with commercial fishing activities.
The UNH Open Ocean Aquaculture (OOA) project was developed to prove that this technology is possible and could provide work and business opportunities for commercial fishermen and fishing cooperatives. The fishermen and co-ops would use their existing vessels to service the longlines. Cooperatives’ inshore infrastructure could process and distribute shellfish.
At April presentations in Maine outlining the projects, Rollie Barnaby, Extension Educator at UNH Coop-erative Extension/NH Sea Grant, said the whole concept provided multiple challenges for engineers at UNH. They had to determine how to design pens, buoys, feeding mechanisms and net cleaning systems for finfish aquaculture in areas of heavy winds and 25-foot waves, and moorings, buoys, lines, hauling gear and other equipment for submerged longline mussel culture that could survive the challenges of an open ocean site.
The longline OOA project has dealt with challenges like blown-out buoys, inadequate ropes and fouling problems. Researchers and fishermen have experimented to determine the best technology to haul the longlines for seeding and harvesting, the best method of socking, the best way to collect spat. Now, after three and one-half years’ tweaking, the shellfish component of the OOA project technology is ready to be transferred to commercial operation. Participants in the project, led by Dr. Richard Langan, are gearing up to help groups of fishermen and individuals establish their own longline systems.
The advantages of submerged open ocean longline shellfish culture, Barnaby, says, are numerous. In a seven- to nine-month growout period, a single 300-foot longline can produce 12,000 to 16,000 pounds of mature mussels. Growing mussels offshore ensures excellent water quality and minimum opposition from commercial or recreational interests. Mussels grown on these longlines have a meat-to-shell ratio that is higher than any other growing method. (But, because the shells are thinner, they need special processing machines to prevent shell breakage.) Mussels are clean and do not need to be purged, and rarely have pearls because these don’t begin to grow until the mussels are about six months old. Submerged culture seems to avoid eider predation, Barnaby said, because the 36-foot lines holding the mussels are suspended from a rope that is 35 feet below the surface.
Several fishermen in New Hampshire, where coastal aquaculture sites are virtually non-existent, have expressed interest. Bob Campbell, manager of the Yankee Fishermen’s Co-op in Seabrook, says the co-op plans to apply for an open ocean lease site for 10 longlines, which would be used by co-op members. “With the groundfish regulations that are coming down, these guys need all the options they can get to diversify,” says Camp-bell. “We have about six guys who are anxious to jump on board. If others see that going well, we’ll get at least six more.”
Choosing a site has been difficult. The UNH project was conducted in state waters off the Isle of Shoals, with state permits. When New Hampshire fishermen determine they want to move beyond state waters for a site, federal permitting will be necessary, and there are presently no federal guidelines in place to cover submerged aquaculture. The UNH team is working on this.
“We’ve had to weigh the ideal water conditions (in federal waters) versus the ease of getting a permit in state waters that have lesser depth,” Campbell says. “There’s no one place where both meet.” The fishermen decided on a site in state waters and have begun the process of applying for the permit.
Mark Peterson, Mussel Raft Aquaculture Program Manager at Great Eastern Mussel Farms in Tenants Harbor, says although the concept of submerged longlines is interesting, he believes Maine state waters are already saturated by various types of fishing and recreational uses. He thinks it will be necessary for people working out of Maine to site submerged longlines, which require larger lease areas than rafts, in federal waters. “Getting federal regulations in place will be a fairly lengthy process,” he notes
Also, Peterson says, if longlines are located in federal waters, harvesting would be taking place in areas not tested by the state for red tide and other biotoxins. A sample from each harvest would need to be taken to the DMR for testing. Whale entanglement regulations might be a further obstacle, but UNH researchers believe the configuration of a longline site minimizes possible entanglement.
Penobscot fisherman Jesse Leach, who raises oysters and hopes soon to begin raising mussels from lines suspended from rafts, says he has been considering submerged longline mussel aquaculture. He has visited the UNH site and other longline operations in Canada. Because an open ocean site requires a larger boat than he owns, Leach is looking at the possibility of siting a submerged longline in a navigational channel where sufficiently deep waters would be available.
The UNH/OOA project is dedicated to providing support for initial commercial ventures. Woods Hole Oceanographic Institution is preparing a business plan that can be used as a model by anyone who wants to obtain financing for submerged longline mussel culture, and OOA participants at UNH will assist interested fishermen with the permitting process. UNH will be on hand to help out in every phase of transferring the technology to commercial application. Campbell of the Yankee Co-op says the members there are counting on this support. “We are totally novice, as green as green,” he says. “Whatever helpful suggestions they can give us will be great.”
Researchers at UNH will continue to evaluate their technology and study mussel spat settlement, which they say they need to understand better to ensure successful commercial ventures. They have marketed the mussels grown at the project as “Isles of Shoals Supremes” to local restaurants and seafood dealers, and customer response has been extremely favorable.
Barnaby will return to Maine to give additional presentations on the UNH project and updates on commercial applications in New Hampshire. UNH invites interested fishermen and others to call and make arrangements to visit their site.
Further information can be obtained at