Rising ocean temperatures driven by human-generated greenhouse gases are already damaging the world’s fisheries—and that toll is on track to get worse without urgent global action to cut planet-warming emissions.
“We were surprised how strongly fish populations around the world have already been affected by warming, and that, among the populations we studied, the climate ‘losers’ outweigh the climate ‘winners.'”
—Christopher Free, UC Santa Barbara
A pair of new studies published Thursday adds to a growing body of research which warns that anthropogenic global warming poses a mounting threat to both populations of marine fish and the more than 56 million people worldwide who depend on fisheries for survival.
First, a study in the journal Science found that from 1930 to 2010, the maximum sustainable yield—or the amount of fish that can be caught annually without endangering future harvests—fell by about 4.1 percent among the 124 marine species analyzed across 38 ecoregions, with some regions seeings declines as high as 35 percent.
“We were surprised how strongly fish populations around the world have already been affected by warming, and that, among the populations we studied, the climate ‘losers’ outweigh the climate ‘winners,'” Christopher Free, a postdoctoral scholar at UC Santa Barbara who oversaw the research while earning a doctorate at Rutgers University, said in a statement.
Given the impacts Free’s team observed—with the most severe losses in productivity seen in the Sea of Japan, North Sea, Iberian Coastal, Kuroshio Current, and Celtic-Biscay Shelf ecoregions—the researchers strongly suggested proactive changes in fisheries management.
“We recommend that fisheries managers eliminate overfishing, rebuild fisheries, and account for climate change in fisheries management decisions,” Free said. “Policymakers can prepare for regional disparities in fish catches by establishing trade agreements and partnerships to share seafood between winning and losing regions.”
He added that “knowing exactly how fisheries will change under future warming is challenging, but we do know that failing to adapt to changing fisheries productivity will result in less food and fewer profits relative to today.”