Fishing for a solution
As stocks dwindle, a team of researchers pioneers new ways to 'farm' fish - miles offshore in the ocean's depths.
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Specifically, for feeding, they can preprogram a solar- and wind-powered electric pump that will direct feed into a hopper. The food is then pushed down through tubes into the fish cage. Feeding occurs every other day during the winter, which is sufficient, as the fish are less hungry in cold months than during warmer ones, when they are fed daily.Skip to next paragraph
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Clearly thrilled with what Langan calls the "miracle of computers and circuitry and remote communications," he says, "We are not in the fish-farming business; we are in the business of developing and implementing technology for the fish market."
On a recent Indian summer morning, it wasn't necessary to shepherd from shore. Weather conditions couldn't have been better. The UNH team of Langan; research technician Forbes Horton; his brother Nate Horton, who helps out with the project on occasion; and boat captain Hunt Howell, a professor of zoology at UNH, ventured out on the Rock 'n' Roll III, their 40-foot fishing vessel, to feed halibut and harvest mussels.
With them, they brought wellies, rubber overalls, sunscreen, and a couple of out-of-town visitors.
The affable crew clearly enjoys its forays out to sea. En route, they chat among themselves and bask in the sun's warmth, knowing it won't be long before winter's chill settles in and the journey becomes less pleasant.
But on arrival at a large orange, solar-powered buoy, the site of cages for 1,200 halibut, they get to work rigging up the feeding contraption - a giant funnel attached to PVC tubes and an electric pump that thrusts fish-oilpellets 50 feet down into the depths of the ocean. The three-year-old halibut enjoy a feeding frenzy that will help grow them to the 15-pound weight necessary for harvesting in the spring.
These are thought to be the first halibut ever raised in open-ocean net pens.
Next, Rock 'n' Roll III hums over to the nearby mussels. By farming the mollusks close to halibut, the fin fish benefit from nitrogen generated by the plant-eating shellfish.
The UNH team raises "rope-cultured" blue mussels on submerged long lines that measure about 1,500 feet. They say that rope culturing results in a greater meat-to-shell ratio than other methods and makes the mussels easier to harvest. The team has adapted this technique - used in Canada, Europe, and New Zealand - to make it usable in the open ocean, where rope-cultured mussels had not been grown before.
For this day's harvest, the crew simply hoist the rope into the boat and run rubber-gloved hands down it, forcing mussels to fall off into a large plastic bucket. Then the real work begins: shucking mussels from horrid-smelling tubularia, a yellowish seaweed that clings to the rope.
Typically, their harvest goes to 11 restaurants in Portsmouth, N.H., as well as to a major local fish market. One of the goals of the project is to refine the technology so that fishermen across New England can use open-ocean aquaculture to meet the needs of their local restaurants and businesses.
But the UNH crew knows they must prove the value of their methods before commercial fishermen will follow their lead.
Open-ocean technology is costly and will require a substantial investment from the private sector. There are also logistical limitations to consider. Sites must have a relatively flat seabed and not too much "energy" - wind and waves in layman's terms.
Fish farmers must also make sure that they do not intrude on sites that are already being used by local fishermen.
Those involved in the project have a feeling of satisfaction that they are on the cutting edge of aquaculture in America, which they all agree is here to stay.
"It's unrealistic to think that fish stocks will recover," says Langan. "There's too many people fishing and too much demand not to drastically hurt the world's supply."
Aquaculture, he concedes, isn't perfect. "Fish farming still needs to learn from past mistakes, use better judgment, and better cages.'
But when done well, he adds, "it's an excellent solution."
• For more information, visit http://ooa.unh.edu.