Study: Climate Change Affects Cod Stocks

A U.S. study has linked environmental factors such as climate change to the collapse of the North Atlantic cod fishery.

University of Massachusetts at Dartmouth researchers determined a recently published study of cod stocks off Canada and New England showed that after falling in the 1970s stocks increased sharply for about five years then began a steep decline again, suggesting environmental factors played a stronger role in the collapse of the cod fishery than previously thought. In the new study, Brian Rothschild and colleagues at UMass Dartmouth argue an interruption in the food chain, possibly caused by climate change, was a key factor in the cod’s disappearance.

These environmental changes were probably as important in influencing declines in cod abundance as the effects of fishing, said Rothschild. The standing stock biomass and weight-at-age statistics for various stocks tend to follow the same pattern. However, when fishing is superimposed on top of an unfavorable environment, it appears to accelerate the negative effects of the environment in bringing about a decline.

The study is reported in the current issue of the journal Transactions of the American Fisheries Society.