The US-led study assessed what proportion of fish is being taken out of the sea, as well as which management tools are working best to prevent further fish stock depletion, over a period of two years. It found some recovery of stocks in waters around the US, New Zealand and Iceland, giving weight to the argument that well-managed fisheries can lead to fish stocks being rebuilt around the world.
The study was led by Dr Ray Hilborn of the University of Washington and Dr Boris Worm of Dalhousie University and follows on from a 2006 paper by Worm and others that showed a rapid and widespread trend toward global fisheries collapse, which divided opinion in the scientific community.
Worm said: "Across all regions we are still seeing a troubling trend of increasing stock collapse. But this paper shows that our oceans are not a lost cause. The encouraging result is that the exploitation rate – the ultimate driver of depletion and collapse – is decreasing in half of the ten systems we examined in detail.
“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."
Long way to go
Fears about reduced fish stocks have escalated in recent times. After analyzing United Nations figures on global marine protected areas, an international team of researchers warned in November that all seafood stocks around the world may collapse by 2050 if fishing continues at its current rate.
Hilborn said: "These highly managed ecosystems are improving. Yet there is still a long way to go: of all fish stocks that we examined 63 percent remained below target and still needed to be rebuilt."
Consumer concern
As consumers have become increasingly concerned about fish stocks, they have looked for reassurance that the fish they are buying is sustainably sourced. This has led fisheries of all sizes to partner with the Marine Stewardship Council (MSC) to assess their practices and ultimately allow food packages to carry the MSC seal which indicates environmentally sustainable procedures.
The Science report found “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 authors wrote.
They said that laws that specifically forbid overexploitation and set targets for rebuilding, such as those in place in the US, have been most successful.
Source: Science
325, 578 (2009); DOI: 10.1126/science.1173146
Rebuilding Global Fisheries
Authors: Boris Worm, et al.