Fish stocks recover as conservation measures take effect, analysis shows
Regions in Iceland, California and north-east US show signs of recovery but North Sea and Ireland still overfished
Global efforts to combat overfishing are starting to turn the tide to allow some fish stocks to recover, new analysis shows. Research from an international team of scientists shows that a handful of major fisheries across the world have managed to reduce the rate at which fish are exploited.
The experts say their study offers hope that overfishing can be brought under control, but they warn that fishermen in Ireland and the North Sea are still catching too many fish to allow stocks to recover. Some 63% of assessed fish stocks worldwide still require rebuilding, the scientists report.
“Across all regions we are still seeing a troubling trend of increasing stock collapse,” said Dr Boris Worm, an ecologist at Dalhousie University in Canada. “But this paper shows that our oceans are not a lost cause. The encouraging result is that exploitation rate, the ultimate driver of depletion and collapse, is decreasing in half the 10 systems we examined. This means that management in those areas is setting the stage for ecological and economic recovery. It’s only a start, but it gives me hope that we have the ability to bring overfishing under control.”
Fisheries winning the battle against overfishing include regions in the US, Iceland and Australia. But fishermen in Ireland and the North Sea are still catching too many fish to allow stocks to recover, the research says.
Pamela Mace of the New Zealand ministry of fisheries, who helped to write the new study, said: “Fisheries managers currently presiding over depleted fish stocks need to become fast followers of the successes revealed in this paper. We need to move much more rapidly towards rebuilding individual fish populations, and restoring the ecosystems of which they are a part, if there is to be any hope for the long-term viability of fisheries and fishing communities.”
The new analysis used catch data as well as stock assessments, scientific trawl surveys, small-scale fishery data and modelling results. It highlighted catch quotas, localised fishing closures and bans on selected fishing gear to allow smaller fish to escape as measures that help fish stocks to recover. Agencies in Alaska and New Zealand have led the world in the fight against overfishing by acting before the situation became critical, says the study, which is published in the journal Science. Fish abundance is increasing in previously overfished areas around Iceland, the north-east US shelf, the Newfoundland-Labrador shelf and California. This has benefitted species such as American plaice, pollock, haddock and Atlantic cod.
“Some of the most spectacular rebuilding efforts have involved bold experimentation with closed areas, gear and effort restrictions and new approaches to catch allocations and enforcement,” the scientists say. But they caution that the study covers less than a quarter of world fisheries, and lightly to moderately fished and rebuilding ecosystems comprise less than half of those.
The isolated success stories, they say, “may best be interpreted as large scale restoration experiments that demonstrate opportunities for successfully rebuilding marine resources elsewhere.” Many nations in Africa have sold the right to fish in their waters to wealthy developed countries that have exhausted their own stocks, the experts said. The move could undermine local efforts to tackle overfishing made by small scale fisheries such as those in Kenya, which are highlighted in the new study.
The North Sea, the Baltic and Celtic-Biscay shelf fisheries are all still declining. Here, Atlantic cod and herring as still declining, while globally populations of large predators such as sharks and rays are in rapid decline.
The new survey marks a public truce in a war of words between Worm, a conservationist, and fellow author Ray Hilborn, a fisheries expert at the University of Washington in Seattle. The spat followed a 2006 study by Worm that made some dire predictions about the state of the world’s fisheries, including the claim that most stocks could collapse by 2048 if present trends continued. Hilborn criticised the research as “sloppy” and said the 2048 claim had “zero credibility” because it used simple records of fish catches to say whether stocks had collapsed.
“I very much hope I will be alive in 2048 and I have given some thought to whether I will have a seafood party or not,” Worm joked at a press conference this week.
Dr Ana Parma, an author of the paper with the Centro Nacional Patagonico in Argentina, said: “This is the first exhaustive attempt to assemble the best available data on the status of marine fisheries and trends in exploitation rates, a major breakthrough that has allowed scientists from different backgrounds to reach a consensus about the status of fisheries and actions needed.”