New York, March 1 (IANS): Climate change has taken a toll on several of the world's fisheries, and overfishing has magnified the problem, researchers have warned.

The study, published in the journal Science, suggests that ocean warming has led to an estimated 4.1 per cent drop in sustainable catches, on average, for many species of fish and shellfish from 1930 to 2010.

In five regions of the world, including the East China Sea and North Sea, the estimated decline was 15 to 35 per cent, according to the study.

"We recommend that fisheries' managers eliminate overfishing, rebuild fisheries and account for climate change in fisheries management decisions," said Chris Free, who led the research at Rutgers University.

Overfishing not only makes fisheries more vulnerable to ocean warming, but continued warming will hinder efforts to rebuild overfished populations, the study suggested.

For the study, the scientists studied the impact of ocean warming on 235 populations of 124 species in 38 ecological regions around the world. Species included fish, crustaceans such as shrimp, and molluscs such as sea scallops.

They combined global data on fisheries with ocean temperature maps to estimate temperature-driven changes in the sustainable catch (known as the maximum sustainable yield) from 1930 to 2010.

Their analysis covered about one third of the reported global catch, and losing species outweighed the winners as the oceans warmed.

The greatest losses were in the North Sea, Iberian Coastal, Kuroshio Current and Celtic-Biscay Shelf regions. The greatest gains occurred in the Labrador-Newfoundland, Baltic Sea, Indian Ocean and Northeast US Shelf regions.