PORTLAND, Maine - The rapid warming of waters off New England is a key factor in the collapse of the region's cod fishery, and changes to the species' management are needed to save one of America's oldest industries, according to a report published Thursday in Science magazine.
Fishery managers say cod spawning in the Gulf of Maine -- a key fishing area between Cape Cod and Canada that touches Massachusetts, Maine and New Hampshire -- is only about 3 percent of sustainable levels, and participants in the fishery that dates to the Colonial era face dramatic quota cuts as a result.
The scientists behind the Science report say the warming of the Gulf of Maine, which accelerated from 2004 to 2013, reduced cod's capacity to rebound from fishing pressure. The report gives credence to the idea -- supported by advocacy groups, fishing managers and even some fishermen -- that climate change has played a role in cod's collapse.
The lead author of the study, Andrew Pershing of the Gulf of Maine Research Institute in Portland, said the gulf is warming at a rate 99 percent faster than anywhere else in the world, and as a result, too many of the fish aren't living past age 4 or 5. Cod can live to be older than 20.
"Every animal has a temperature range that they prefer. The Gulf of Maine, for cod, is really at the warm end of that," Pershing said. "If you warm it, you push it somewhere that's really uncomfortable."
The report comes amid a collapse in commercial catch of Atlantic cod, which are also fished off New England in Georges Bank, where the stock has also collapsed. Catch fell from more than 33 million pounds in 2001 to less than 5 million pounds in 2013.
As a result, the price of local cod has risen in New England. Now, much of the cod in fish and chips there is from places such as Iceland and Norway, and sometimes restaurants use a different species altogether.
David Goethel, a biologist and longtime New Hampshire fisherman, said the study reflects what he sees at sea. He said it's important that published science now backs that up.
But he also said fishing managers are trying to rebuild cod stocks to unrealistic levels, which results in low quotas for fishermen. Instead, he said, they should set quotas that reflect the status of the stock. A New England fishing regulatory council voted to reduce the total allowable Gulf of Maine cod catch limit from 1,550 metric tons to 386 metric tons a year ago. In the early 2000s, it was 8,000 metric tons per year.
"We need to manage for what is here now," said Goethel, himself a former member of the fishing regulatory council. "Otherwise, we're just going to leave enormous amounts of protein in the water for no reason, for what's basically a bureaucratic reason."
The report said regulators need to incorporate environmental factors in managing commercial species. Jud Crawford, science and policy manager of U.S. Oceans, Northeast for Pew Charitable trusts, said that could mean placing a premium on conserving cod habitat.
Malin Pinsky, a biology professor at Rutgers University who was not involved in the study, said the findings help explain the northern shift in the cod's population. Researchers reported this month that numbers are improving in the colder waters off Newfoundland and Labrador.
"What we're learning about cod are the same kind of processes that are likely to play out in a wide range of important fish in this and other regions," he said.