Ecologists have recently touted marine reserves, where all fishing is prohibited, as a promising way to help reverse the decline of the world's fisheries. Ben Halpern, a graduate student in marine ecology at the University of California at Santa Barbara, has bolstered the argument by documenting how quickly the seas will heal if only we leave them alone.
Various researchers have shown that marine reserves have twice the density of fish as in non-protected areas, and that the fish tend to be larger, but nobody knew how long the recovery process takes. When Halpern analyzed data from more than 100 studies of 80 "no take" zones worldwide, he was stunned. Once a reserve is established, fish populations shoot up and reach equilibrium within just one to three years. "These results are extremely encouraging from an ecological perspective as well as a fishing perspective," says Halpern.
Such rapid recoveries could help fish bounce back from natural population crashes, which other studies have shown can be triggered by climate change. But biologists estimate 25 to 50 percent of the world's oceans need to be protected to maintain sustainable fish populations in the face of human and natural threats. At present, marine reserves make up less than 0.01 percent.