Collapse of all wild fisheries predicted by 2050

Posted: 8 November 2006

All species of wild seafood currently fished are projected to collapse by the year 2050, according to a new four-year study by an international team of ecologists and economists. Collapse is defined as 90 per cent depletion.

The scientists warn that the loss of biodiversity is "profoundly" reducing the ocean's ability to produce seafood, resist diseases, filter pollutants, and rebound from stresses such as overfishing and climate change.

Global loss of seafood species. Shown is the current trend in fisheries collapses, and extrapolated to 2050.

"Whether we looked at tide pools or studies over the entire world's ocean, we saw the same picture emerging," says lead author Boris Worm of Canada's Dalhousie University. "In losing species we lose the productivity and stability of entire ecosystems. I was shocked and disturbed by how consistent these trends are - beyond anything we suspected."

The study, published in the journal "Science" in November, was based at the US National Center of Ecological Analysis and Synthesis, NCEAS. It contains some good news - the data show that ocean ecosystems still hold great ability to rebound. But the scientists found that every species lost causes a faster unraveling of the overall ecosystem.

Conversely, every species recovered add to overall productivity and stability of the ecosystem and its ability to withstand stresses. "Every species matters," the scientists say.

"Unless we fundamentally change the way we manage all the oceans species together, as working ecosystems, then this century is the last century of wild seafood," says co-author Steve Palumbi of Stanford University.

Herring fishing in the Baltic Sea. © Greenpeace/NoelMatoff
Herring fishing in the Baltic Sea. © Greenpeace/NoelMatoff
Herring fishing in the Baltic Sea.© Greenpeace/NoelMatoff
The analysis is the first to examine all existing data on ocean species and ecosystems, synthesizing historical, experimental, fisheries, and observational datasets to understand the importance of biodiversity at the global scale.

The results reveal that progressive biodiversity loss not only impairs the ability of oceans to feed a growing human population, but also sabotages the stability of marine environments and their ability to recover from stresses.

"The data show us it's not too late," says Worm. "We can turn this around. But less than one percent of the global ocean is effectively protected right now."

"We won't see complete recovery in one year, but in many cases species come back more quickly than people anticipated - in three to five to 10 years. And where this has been done we see immediate economic benefits," Worm said.

The authors conclude that restoring marine biodiversity through an ecosystem based management approach - integrated fisheries management, pollution control, maintenance of essential habitats and creation of marine reserves - is essential to avoid serious threats to global food security, coastal water quality and ecosystem stability.