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Warming Waters Are Changing Global Fish Catches

BOSTON — A sweeping new study concludes that climate change is putting global fish stocks on the move.

Published in the journal Nature on Wednesday, the study (PDF) shows that for 40 years now, warming waters have been driving global fish stocks toward cooler, deeper waters. That includes Northeast groundfish, such as cod and flounder.

When fishery biologist Jud Crawford was growing up in New England, he never saw some of the species that are now common in Northeast waters.

“Populations of blue crab, which is something we think as being something we see in the Chesapeake Bay,” Crawford said. “We see Atlantic croaker, which we think of as a mid-Atlantic species moving increasingly northward.” And he sees far fewer cod, too.

Warming Waters

Last year, the surface temperatures in the Northeast Shelf Large Marine Ecosystem were the highest ever recorded. But the observed changes in local fish populations could be caused by any number of things.

But now, for the first time, a widespread study concludes that it’s not a local problem.

“Global ocean warming already affects the fisheries around the world by changing the species compositions of the catch,” explained William Cheung, a fisheries scientist at the University of British Columbia and the lead author of the study. He analyzed fish catches globally from 1970 to 2006. What Cheung found is a clear trend — not just here, but all over the world.

“We are seeing changes in composition of fish catch, with increasing catch of warmer-water species and less proportions of cooler water species,” Cheung said.

Cheung said the trend of more tropical and sub-tropical species is especially acute in the more temperate American waters off of Alaska and New England.

Commercial Fishing

Commercial fishermen in the Northeast have been seeing this. As a group, they didn’t catch nearly as many cod and other groundfish this past year as they were allowed.

“Some of our largest processors here in New England have had to resort to importing from Iceland, Norway, Newfoundland and Canada as primary source of haddock and cod,” said Richie Canastra, co-owner of the New Bedford and Boston Seafood Auctions.

Canastra spoke at a recent rally on Boston’s fish pier, where he called for raising catch limits.

But the study authors suggest otherwise. And so does fishery biologist Jud Crawford with The Pew Charitable Trusts, which partly funded the study. He said the way to help groundfish, such as cod and haddock, that are being squeezed by warmer waters is to lower other pressures, like commercial fishing.

“A very important response is going to be to substantially improve the way that we protect ocean habitat,” Crawford said.

The new study could inform a policy decision due next month. The National Marine Fisheries Service is set to decide whether to open up 5,000 square miles of protected waters to bottom trawl fishing.

CLICK TO ENLARGE: This graphic shows how warming oceans have been reshaping fisheries since 1970. (Pew Ocean Science Division of The Pew Charitable Trusts)

CLICK TO ENLARGE: This graphic shows how warming oceans have been reshaping fisheries since 1970. (Pew Ocean Science Division of The Pew Charitable Trusts)

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  • http://www.facebook.com/futo.buddy Futo Buddy

    why dont the fisherman just target the warm water species instead?kill two birds with one stone as it were

  • http://twitter.com/zeldamacgregor Zelda MacGregor

    With New England experiencing effects of climate change already, why would anyone even think about opening up protected habitat? NOAA has already said habitat protection is the best way to ensure our area fish adapt to climate change. It doesn’t make any sense to open this protection. Mr. Crawford is right; we need to talk about protecting our marine habitats to stop these issues, not open them up further.

  • David Cowie

    The fish stock needs the protective zones in order to first thrive, and then potentially adapt to the sure change in habitat conditions. Opening the zones and decreasing the protections will hasten the species demise. Keep the zones protected for the preservation of the stock.

  • http://www.facebook.com/jasonebowie Jason Bowie

    I can’t believe that anyone is even considering opening up additional areas for fishing. There is plenty of ocean to fish in already, and opening up restricted areas would do nothing but drive already endangered species to extinction. If commercial fishermen are finding that they have smaller catches year over year, opening up more areas can not possibly be a long term answer.

  • Doug O’Roak

    It’s very short-sighted to consider opening more fishing grounds, especially in New England where this is already a significant decrease in the Cod population. The Cod are already under stress due to the changing climate conditions, and to further stress them by opening up more commercial fishing areas would compound the problem – not help it. The best thing to do would be to further protect the Cod population to allow them to adapt.

  • http://twitter.com/KevinOR5 Kevin O’Reilly

    NOAA needs to get serious about dealing with climate change.

  • http://www.facebook.com/Bosenlaw Theodore Bosen

    I am a co-plaintiff with Cape Cod Bay Watch in a lawsuit against government agencies who are failing to enforce Federal and State Environmental Laws against the Pilgrim Nuclear Power Station in Plymouth for killing fish by illegally polluting Cape Cod Bay with excessive heat and chemicals, but our efforts will simply be undone if habitat protection is not also enforced in light of the additional adverse effects of our changing climate. The mussels in the local coves are already gone. There is no time to waste. We must fight to protect local fisheries now or lose them!

  • Mary Burns

    I have lived in New England my whole life, and watching the destruction of our beautiful coastline has been difficult. I’m glad there are groups that are working to protect our marine habitats and I hope NOAA will join them in keeping those closed habitats CLOSED and safe as they adapt. It’s what is right.

  • Amy Wood

    We need to protect the Cod! Opening up more habitat to fisheries is not the answer. More research during protection is the answer, and it seems like most experts agree. I grew up on the water and I don’t want to see it take any more damage because of climate change. There are things we can’t go back and fix, but there are things we can protect: our marine animals and habitats are one of them. Let’s protect them and take our time figuring out what is the best course of action for everyone involved (including fish and fishermen) before making a hasty judgement that makes things worse!

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