If Scott Lindell is right, fish in the ocean can be trained to swim to the sound of a dinner bell until, one day, they’ll be dinner.
Lindell, director of the Scientific Aquaculture Program at the Marine Biological Laboratory, leads a project which will place 5,000 black sea bass in the waters off Buzzards Bay near the Weepecket Islands in Massachusetts.
The fish will be released into what is called an Aquadome, a mesh-covered geodesic half-dome structure 32 feet in diameter, 16-feet tall, and installed on the seafloor at a subtidal water depth of 35 feet. The structure will be secured through anchor lines and five 1,200-pound deadweight anchors.
That’s the easy part. The science part is that, in a process called “acoustic conditioning,” the fish will hear an underwater tone before regular feedings and, hopefully, associate the two. Gradually, the fish will be released into the wild to forage on their own but will still receive occasional feedings at the dome.
At the end of the project, the dome’s “dinner bell” will ring for the last time and researchers will tally up how many of the fish have returned.
“Memory is a key part of this,” says Lindell, noting that fish in the MBL labs in Woods Hole have responded to audio cues after as many 10 days without one. Researchers are now trying to extend that period to two weeks or longer.
The project is known in the close-knit Woods Hole community, and Lindell has heard opinions from many people. “There’s some healthy skepticism if it will work,” he says with a laugh.
But he’s also heard from schoolchildren who write to him about experiences with their own fish tanks and from folks in Norway who say the concept is similar to fish farming practices in that country’s fjords.
“The main motivation is to keep Cape Cod and other coastal communities as working fishing areas,” says Lindell. If successful, the project’s method of aquaculture, whereby fish are fed part of their diet but fend for themselves at other times, could provide relief for fish stocks trying to rebuild and for local fishermen struggling to make a living.
To that end, the project has an economist on board and meticulously records expenses, all the better to determine at what point such aquaculture becomes economical.
“We don’t want to give the fish all of their nutrients because that’s expensive,” notes Lindell. “We want them to forage.”
Lindell also touts environmental benefits, saying that fish farmed by acoustic conditioning would have less stress and disease than other fish farms, much in way free-range chickens are healthier than their more confined counterparts.
Black sea bass were selected, says Lindell, because the fish is prized by both recreational and commercial fishermen. It’s also a fish that has seen its numbers dwindle and whose traditional habitats are themselves under stress.
The permitting process is under way, and researchers hope to have the Aquadome in the water by late May. No matter what the results, the dome will be pulled from the waters by late October because the fish will be heading to warmer climes by then.
All of the fish will come from two to three dozen parent fish of local origin, says Lindell. At first, says Lindell, researchers will drop no more than five pounds of feed per day, roughly the equivalent of the bait found in two to three lobster parts. Later in the project, greater amounts of feed will be dropped but the fish will be swimming greater distances. As a result, says Lindell, any effects caused by the feed or fish waste should be negligible.
Lindell admits his worst fear is that the black sea bass will become food for larger fish, but that the project’s location near the Weepecket Islands should provide much-needed cover. Local fishermen who catch the tagged fish will receive a reward if they return them to researchers.
“We want to incentivize it but it’s only if you return the tag on a legal-sized fish,” he says. “If it’s undersized, you have to throw it back.”
While research in the lab is encouraging, Lindell doesn’t know what will happen when the fish are released into the Aquadome in Buzzards Bay. And that, he says, is just the point.
“There’s no such thing as failure in science,” Lindell says. “One extreme is that the fish will never come back. Another extreme is that they’ll never leave. Then there’s that somewhere in the middle. But, regardless, we’re going to learn a tremendous amount.”
The project is funded through a $270,000 grant from the National Oceanic and Atmospheric Administration.
Falmouth Bulletin
