May 5, 2022 — “For the first time in about 20 years we’ve seen and are tracking a successful year class of cod, and they seem to be growing at a very good rate,” said Kevin Stokesbury, a fisheries science professor at UMass Dartmouth leading a multi-year survey of codfish in the Gulf of Maine.
Stokesbury has a history of using scientific innovation to produce new findings that upend fishing regulations. In the 1990s, he devised a new way of counting scallops that helped open up a tightly regulated fishery.
A typical government-led survey determines scallop numbers by dredging the ocean floor, counting the scallops it pulls up, and estimating what percentage that is of the total scallops in the sample area. Stokesbury’s surveys rely on pictures of the ocean floor instead. A team of his undergraduates count all the scallops in their sample areas one-by-one, eliminating much of the guesswork.
Stokesbury’s method for counting scallops was peer reviewed and eventually incorporated into the government’s periodic stock assessments, which form the basis of fishing regulations in America. In the early 2000s, regulators had already suspected scallops were rebounding to some extent, but Stokesbury’s findings upended what they had been saying for years.
“They thought there were two to three times as many scallops in there,” Stokesbury said, “and there were actually about 14 times as many.”
But the UMass Dartmouth scientist has his own critics when it comes to codfish. One of them has an office down the hall from him.
Professor Steve Cadrin, a fisheries scientist leading a periodic review of how the government assesses cod stocks, said the cod fishery has opened up prematurely once before.
“We’ve seen other year classes that have not survived,” Cadrin said.
Some years, Cadrin said NOAA’s projections have been overly optimistic.
“They led to continued overfishing and the stock hasn’t rebuilt,” Cadrin said. “It’s a lot more than just a heartbreak. There’s been a lot of fishery restrictions because of that.”