"The question of the influence of fishing and the influence of the environment is tangled up," said Brian Rothschild, a professor of marine science at the University of Massachusetts, Dartmouth, who has studied aquatic stocks for more than five decades.
"There is no question that as some of the environment changes occur, some of the fish stocks are going to change," he said. "We don't know enough about it to know what's going to increase and what's going to decrease."
"It's regulation after regulation after regulation," complained Michael Dearborn, 66, a commercial fisherman since 1969. "They treat the industry like a centipede, cutting off one leg at a time, snip, snip, snip, until it starves."
"Some of the fish stocks are showing improvement," acknowledged Maggie Mooney-Seus, a spokeswoman for NOAA, the agency responsible for enforcing the limits. "But there is too much fishing pressure on a lot of them. Right now, fishermen are going to have to have cuts."
Quotas on the fishermen remain the chief mechanism to react to dwindling stocks. Those quotas remain largely a function of numbers of fish caught versus a sampled estimate of the numbers of fish in any one stock; there is little room for forward calculations about how climate change will skew the future.
"I don't think the fisheries managers are equipped to quantify the effects of global warming at this point," said Peter Baker, manager of the New England Fisheries Campaign for the non-profit Pew Environment Group. "They have no tools.
"I don't think we understand the impacts of climate change very well at all," said Paul Parker, who works with the Cape Cod Commercial Hook Fishermen's Association. "We are struggling to understand it all. It's difficult to discern what causes what."
For example, the fishermen say there is a bumper crop of dogfish shark, which strip their hooks and gobble up groundfish. It is tough, they say, to sort out whether fish populations are hit harder by human fishing, the sharks' appetite, climate change or some other environmental shift.
Read the complete story from Scientific American.