World fish stocks worse than feared new study shows
September 27 2012 Lewis Smith
Spear fisherman off the Solomon Islands
The health of the world’s fisheries is much worse than official figures suggest, researchers have found.
An estimated 4,000 fisheries are now believed to be overfished after researchers devised a way of estimating stock levels in previously unassessed fisheries.
Stocks in almost one in five of the newly assessed fisheries are estimated to have collapsed beyond the point that it is considered viable to try to catch and land them.
The findings indicate that the proportion of fisheries being overexploited is 40 per cent worldwide, up on the 32 per cent cited two years ago by the United Nation’s Food and Agriculture Organisation (FAO).
Moreover, the FAO figures were based on stock assessments of the 441 fisheries for which reliable data has been gathered and which account for less than 20 per cent of the global catch, but the new research looks at 10,000 fisheries.
However, the researchers behind two reports are confident that if prompt action is taken, much of the decline can be reversed and worldwide catches could be boosted by up to 40 per cent, with the number of fish in the seas rising by up to 56 per cent.
The key, they say, is ensuring there is effective management and enforcement of the rules. They are particularly keen to see extensive rights-based fisheries management which gives fishermen a vested interest in fishing stocks sustainably.
A number of rights-based schemes have been operated in recent years, including a pilot in Belize where 70 per cent of fishermen reported bigger catches and 12 projects in the Philippines where preliminary data shows the quantity of fish in the water rose 47 per cent.
The conclusions were reached in a study published in the peer-reviewed journal Science as part of a wider report, Charting a Course to Sustainable Fisheries, released by the consultancy California Environmental Associates.
Professor Christopher Costello, the lead author of the Science report and an economist at the University of California, Santa Barbara, said the study was necessary because data for the majority of fisheries remains deficient.
"For most fisheries, we simply didn't know how many fish were out there and whether their populations were trending up or down," he said. “Without good information on fish populations, managing sustainably can be a hard thing to do.
"Without good population estimates, political pressure tends to dominate decision making, and we end up catching too much. Over time, this can lead a fishery to collapse."
He and his colleagues were able to estimate the state of unassessed stocks by devising models that took into account the data that had been collected on them, information on the fish species such as the growth rates and ages of sexual maturity, and details of the history of fisheries that are well documented.
Professor Costello is convinced that fish stocks and catches – which have been declining at a rate of about 500,000 tonnes per year since 1988 when landings peaked at 80 million tonnes – can be restored by running fisheries sustainably and that this will bring jobs, wealth and food: “In the long run it will provide increased food, increases economic prosperity and, of course, conservation because there will be more fish in the sea.”
But he warned that significant action is needed over the next decade: "The good news here is that it's not too late. These fisheries can rebound. But the longer we wait, the harder and more costly it will be to bring these fisheries back. In another ten years, the window of opportunity may have closed.”
Professor Steve Gaines, a biologist and the dean of the Donald Bren School of Environmental Science and Management, University of California Santa Barbara, was one of the researchers and joined the call for better fisheries management.
"Strong management could increase the number of fish in the ocean by over 50 percent," he said. "When fish populations are healthy they produce more young. It may seem paradoxical, but we can get more fish on our plates by leaving more in the water
"This isn't something where we need another twenty years of science. We know what it takes."
Among the people to welcome the publication of the reports were Michael Arbuckle, senior fisheries officer at the World Bank, who said: “The silver lining here is we have proven solutions. The challenge is to scale these solutions up.”
And Brett Jenks, chief executive of conservation organisation Rare, added: “We see a compelling silver lining, unlike most gloom and doom findings about fisheries. There is compelling evidence fishery recovery is possible.”
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