A study by scientists and economists has estimated that better management of the world's wild fisheries could feed 20 million more people, especially in impoverished countries.
Researchers at the Fisheries Centre in Vancouver say the first global estimate of the value of the industry, set at US$240 billion (A$258 billion), but warned that government subsidies encourage over-fishing that is destroying the resource.
The work is "the first big-picture analysis of the value fisheries have for people worldwide," says Rebecca Goldburg, a scientist with the Pew Environment Group, which funded the research.
Published in the Journal of Bioeconomics , the report also found that fisheries could feed 20 million more people if over-fishing were eliminated; ocean-related sports fishing, whale watching and diving, account for one million jobs, a value up to US$47 billion (A$50.5 billion); and of the US$27 billion (A$29 billion) in annual fishery subsidies, such as for cheap fuel, 60% worsens over-fishing that destroys fish stocks.
'Good economic sense'
"Maintaining healthy fisheries makes good economic sense," says Rashid Sumaila, director of the Fisheries Centre at the University of British Columbia , Canada, which led the research.
The value of fisheries was historically measured by the landed value at dockside, which in 2000 was US$85 billion (A$91.4 billion) worldwide, says Sumaila.
The study is the first globally to put a figure on the industry taking into account the many economic spin-offs, he says.
"In terms of the global economy, this is not a big amount, you're talking a small fraction of trillions," says Sumaila. But he says an accurate assessment of the ocean harvest - as well as its food security worth - will give governments an incentive to better manage stocks.
Sumaila says up to half of all wild fish populations are now over-fished and in the process of "crashing" or have already crashed - as did once-bountiful northern cod in the North Atlantic nearly 20 years ago.
"If we don't do something now, we are likely to lose most of these benefits," says Sumaila. With better management, "we could have met the needs of 20 million people in malnourished countries."
He recommends governments start by redirecting industry subsidies from fuel and other areas that worsen over-fishing, to research and helping fishers adopt sustainable methods.
"Large developed countries are spending twice the amount of taxpayer money on global fisheries subsidies that encourage overfishing than they are on subsidies that protect oceans," says the report.
The researchers used data from international catches of wild fish in 2000, within the economic zones of all countries. Further research now under way using data up to 2008 will include an analysis of the corporate structure of the fishing industry, says Sumaila.