Study Finds We’re Eating Seafood to Extinction

By Carrie Peyton Dahlberg, The Sacramento Bee, Calif.

Nov. 3–We are scooping life out of the world’s oceans so fast that if the trend continues, every seafood species now fished will collapse by 2048, a sweeping evaluation published today in the journal Science predicts.

With our dining favorites depleted, “we might be eating things like plankton or sea squirts,” said UC Davis marine ecology professor Jay Stachowicz, one of 14 authors on three continents who assembled the analysis.

Stachowicz and many of his co-authors stressed that we can avert such dire scenarios by taking to heart their key conclusion: that a diverse ocean, rich in many species, will be more resilient and more productive.

The study joins a steady stream of policy papers and analyses warning that ocean life is dwindling and must be managed from a broader “ecosystem” perspective to thrive for future generations.

In a telephone press conference Thursday, the authors called for more protected areas, ocean “zoning” to limit destructive activities and replacing single-species regulations with ones to preserve whole ecosystems.

While U.S. officials are interested in some of those ideas, they are far less alarmed than the international research team.

“People ought to be concerned but not overly concerned, particularly in the United States,” said Steve Murawski, chief scientist for the National Oceanic and Atmosphere Administration’s National Marine Fisheries Service.

Fisheries regulators have a very different idea of species “collapse” than the research team used in its analysis. U.S. officials figure when we’ve lost three-fourths of the fish needed to ensure the maximum sustainable yield, that’s collapse.

By contrast, the new paper assumes a species has collapsed when the current catch is 90 percent lower than the biggest catch on record.

We don’t have enough data to know which definition will best preserve the sea’s riches, although it’s safer to err on the side of abundance, said Paul Siri, director of the California Ocean Science Applications Program, a state-sponsored effort to improve ocean monitoring.

Siri, who is not associated with the study, called it a “fascinating” effort to better quantify what happens as species decline.

“You don’t get a publication like this in Science unless it’s been peer reviewed by very good folks,” he said. But given its content, “my guess is there will be some stones thrown.”

Stones came quickly from the National Fisheries Institute, which dubbed the study “puzzling,” because federal definitions say many of the fish popular with Americans are at sustainable levels today.

Ray Hilborn, a professor of aquatic and fishery sciences at the University of Washington, called the projection of collapse “ridiculous.” When one species crashes, he said, people simply turn to others.

Even critics, though, acknowledged that big fish in the open ocean, stalked by international fleets, are in decline and that fish menus will be different four decades from now. Maybe they will include more farmed fish, or maybe tinier ones, just a few inches long.

And in Stachowicz’s fears, maybe the shell-less, rubbery creatures called sea squirts, which he says look like little globs of goo and don’t taste much better, will be on future menus.

Stachowicz was part of a research team — headed by Boris Worm of Dalhousie University in Canada — which started out four years ago to answer a simple question: Why should people care that more marine species are going extinct?

Backed by the National Center for Ecological Analysis and Synthesis at UC Santa Barbara, the group came at the question four ways, producing basically four studies wrapped into one.

The experts reviewed 50 years of fishing yields in 60 large ecosystems around the world to conclude that close to one-third of all fished species have already collapsed, and the rest will go by 2048 if nothing changes.

They evaluated bird, plant and marine life in 12 coastal ecosystems, including the San Francisco Bay, though historical and archaeological records stretching back as far as 1,000 years to conclude that diverse estuaries are healthy estuaries. A decline in species count was associated with fewer wetlands and seagrass beds to filter toxins out of the water, and fewer “nursery” areas critical for breeding.

They compared studies done in and around four dozen marine protected areas and fish closure areas, crunching the findings through a “meta analysis” that found more diverse ecosystems also drew more tourism dollars, had fewer up and down swings in population and, where fish could be taken, had more productivity.

Finally, they compared 32 small-scale studies that manipulated ecosystems to chart their effect on marine life and concluded that more diverse ecosystems promote faster growth and are more resilient in the face of change.

“Diversity seems to be providing some sort of insurance policy against future change,” said Stachowicz, noting that could be particularly important as climate change or other human activities disrupt the sea.

“Diversity is a good thing in our diet, it’s a good thing in our stock portfolios, so why shouldn’t it be a good thing for our oceans?” he said. “No one species gives us all the things we need to make an ecosystem healthy.”

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