March 26, 2008
Pavlov’s Fish – Black Sea Bass Get ‘Sound’ Training
Researchers in Massachusetts hope that one day fishing won't require bait.
Instead, the team at Woods Hole Marine Biological Laboratory wants to train fish to voluntarily swim to an underwater cage for harvesting by using Pavlovian and trace conditioning.
"It sounds crazy, but it's real," said Simon Miner, a research assistant at the Marine Biological Laboratory at Wood's Hole.
The team has already received a $270,000 grant for the project from the National Oceanic and Atmospheric Administration.
The goal is to one day be able to sustain the black sea bass population by reducing the costs of fish farming, a crucial source of the world's seafood. Ideally, the fish would be able to roam the open seas and grow to their full potential until being called back to the cage for harvesting.
"We're looking for innovations that will actually make a difference for coastal communities and the environment," said Michael Rubino, manager of NOAA Aquaculture. "It fits in both."
Recently, Scientists in Japan were able to keep fish in a certain area using sound, allowing them to be traditionally caught.
Last summer, Miner showed that fish could respond to sound and conditioning by placing fish in a circular tank and setting off a tone before dropping food into an enclosed feeding area in the tank. After playing the tone for 20 seconds, three times a day for two weeks, "you have remote-control fish," Miner said.
"You hit that button, and they go into that area, and they wait patiently," he said.
The next step is to determine how long the bass can remember the link between the tone and food.
After feeding the fish outside of the designated feeding zone for a few days, Miner returns to sound the tone. Some fish forgot after five days, while others remembered as long as 10. Miner said the strength of memory seems tied to how long the fish are trained.
By May, the memories of about 5,000 fish will be put to the test as researchers bring them to a feeding station called an "AquaDome" in Buzzards Bay.
Researchers will train the fish in the AquaDome by feeding them after sounding the tone. Once they think the fish have learned to respond, they will be released. After a day or two, scientists will sound the tone once more to see how many fish return to the feeding zone. The tone will have a range of about 100 meters in every direction.
Randy MacMillan, president of the National Aquaculture Association, said he is not convinced that the fish will respond to training.
"My experience with fish is they will wander far and wide," he said, adding that many fish will also be lost to predators.
He also thinks the idea will be hard to sell to fish farmers.
"The commercial side is going to be skeptical," said MacMillan.
Miner said the real test will come this spring, when the fish head to Buzzards Bay.
"There's probably 18,000 ways for it to go wrong and only one way to go right."
Illustration of Black Sea Bass by Diane Rome Peebles. Provided by the Florida Fish and Wildlife Conservation Commission, Division of Marine Fisheries Management
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Woods Hole Marine Biological Laboratory