Placement of marine reserves is key

Focusing on the heaviest-fished areas can help meet conservation goals

SAN DIEGO — Saving both fish and the fishermen who depend on them appears to come down to one thing: location, location, location.

Marine protected areas, which currently limit fishing in 1.6 percent of the waters claimed by countries, need to be located in the right spots to have the maximum effect, researchers report. The work comes in a suite of papers published online February 22 in the Proceedings of the National Academy of Sciences and presented at the annual meeting of the American Association for the Advancement of Science on February 21.

In the Black Sea, for instance, setting aside just 20 to 30 percent of the most affected areas within marine reserves could accomplish nearly all the goals of protecting the entire reserve, reports a team led by Benjamin Halpern, a marine scientist at the National Center for Ecological Analysis and Synthesis in Santa Barbara, Calif. This suggests that precisely placing the reserves, he said, “can have a dramatic effect on their ability to improve overall ocean health,” as measured by a suite of factors such as pollution and fishing.

The number of marine protected areas is soaring. The world’s governments are nowhere near their stated commitment to protecting between 10 and 30 percent of their waters by 2012, but hundreds of new reserves have sprung up in recent years.

Not all of them are effective, however. Of 564 small reserves studied in the Philippines, for instance, only about one-third were functional, according to work by Richard Pollnac, an anthropologist at the University of Rhode Island in Kingston. The rest were not patrolled or monitored adequately to meet their conservation goals, he says.

Halpern’s work could help illuminate which areas are worth protecting. The biggest potential gain, he said, comes in areas that are heavily fished, where setting aside large chunks led to ocean health improvements of up to 50 percent. In other areas where fishing was less dominant, the overall ecosystem didn’t improve that much even as reserves were made bigger.

Managing marine protected areas can meet conservation goals while benefiting fishermen who work nearby, said Andrew Rassweiler, a biologist at the University of California, Santa Barbara. He is a coauthor of another new study, which modeled how fish larvae disperse through the ocean from a marine protected area in southern California. A nearby fishery can improve its economic return by as much as 10 percent if it tracks how and where the larvae grow to big fish it can catch, he reported at the meeting.

“People fishing can make more money with smaller impacts on the species being fished,” he said.

Alexandra Witze is a contributing correspondent for Science News. Based in Boulder, Colo., Witze specializes in earth, planetary and astronomical sciences.

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