WASHINGTON -- An international group of ecologists and economists warned yesterday that the world will run out of seafood by 2048 if steep declines in marine species continue at current rates, based on a four-year study of catch data and the effects of fisheries collapses.
The paper, published in the journal Science, concludes that overfishing, pollution, and other environmental factors are wiping out important species around the globe, hampering the ocean's ability to produce seafood, filter nutrients, and resist the spread of disease.
"We really see the end of the line now," said lead author Boris Worm, a marine biologist at Canada's Dalhousie University. "It's within our lifetime. Our children will see a world without seafood if we don't change things."
The 14 researchers from Canada, Panama, Sweden, England, and the United States spent four years analyzing fish populations, catch records, and ocean ecosystems to reach their conclusion. They found that by 2003, the last year for which data on global commercial fish catches are available, 29 percent of all fished species had collapsed, meaning they are now at least 90 percent below their historic maximum catch levels.
The rate of population collapses has accelerated in recent years: As of 1980, just 13.5 percent of fished species had collapsed, even though fishing vessels were pursuing 1,736 fewer species then. Today, the fishing industry harvests 7,784 species commercially.
"It's like hitting the gas pedal and holding it down at a constant level," Worm said in an telephone interview. "The rate accelerates over time."
Some American fishery management officials, industry representatives, and academics questioned the team's dire predictions, however, saying countries such as the United States and New Zealand have taken steps in recent years to halt the depletion of their commercial fisheries.
"The projection is way too pessimistic, at least for the United States," said Steven Murawski, chief scientist for the National Marine Fisheries Service. "We've got the message. We will continue to reverse this trend."
The National Fisheries Institute, a trade group representing seafood producers as well as suppliers, restaurants, and grocery chains, said in a statement that most wild marine stocks remain sustainable. The group's spokeswoman, Stacey Viera, added that because the global demand for seafood has already outstripped the amount of wild fish available in the sea, her group's members are meeting the need in part by relying on farmed fish. "To meet the gap between what wild capture can provide sustainably and the growing demand for seafood, aquaculture is filling that need," she said.
But several scientists challenged that prediction and questioned why humanity should pay for a resource that the ocean had long provided for free. "It's like turning on the air conditioning rather than opening the window," said Stanford University marine sciences professor Stephen Palumbi, one of the paper's authors.
The possible collapse of commercial fisheries could have a serious impact on the global economy, said Gerald Leape, vice president for the advocacy group National Environmental Trust.
The industry generates $80 billion a year, Leape said, and more than 200 million people depend directly or indirectly on fishing for their main source of income.