University World News
09 August 2009
Issue: 0088

An international assessment of fish stocks around the world shows some attempts to reduce over-fishing are starting to work. A two-year study by scientists examined trends in fish abundance, the proportion of fish taken out of the sea, and the ways that managers used to limit fishing and rebuild depleted fish stocks.

They found the steps taken to curb over-fishing were beginning to succeed in five of the 10 large marine ecosystems they examined. The rate of fishing had been reduced in several regions around the world, resulting in some stock recovery and bolstering the case that sound management can contribute to the rebuilding of fisheries.

The research was led by US scientists Dr Boris Worm of Dalhousie University and Dr Ray Hilborn of the University of Washington. Among the fisheries showing positive trends were several regions in the US, Iceland and New Zealand.

But Hilborn said there was still a long way to go: “Of all fish stocks that we examined, 63% remained below target and still needed to be rebuilt.”

Worm added there was still a troubling trend of increasing stock collapse across all regions but said the research showed that oceans were not a lost cause: “We are seeing recovery in overall ecosystem structure, even if some species aren’t fully recovered yet,” he said.

The authors cautioned that their analysis was mostly confined to intensively managed fisheries in developed countries, where scientific data on fish abundance were collected. They also pointed out that some excess fishing effort was simply displaced to countries with weaker laws and enforcement capacity.

Techniques successfully used to manage fisheries included catch quotas, fishing closures, ocean zoning, selective fishing gear, community co-management and economic incentives such as individual transferable quotas.

An Australian researcher involved in the study, Dr Beth Fulton, said exploitation rates in the Australian fisheries covered by the research had more than halved since the early 1990s. “As a result we are seeing recovery in overall ecosystem structure, even if some species aren’t fully recovered yet.”