New England fishermen have mixed feelings about a programme designed to allow overfished species to recover. Mark Schrope reports on how catch shares have scientists fishing for answers. Many researchers, conservationists and even some fishermen have grown increasingly enamoured of catch shares and hail an emerging policy at the National Oceanic and Atmospheric Administration (NOAA) encouraging their widespread use as part of the solution for ailing oceans. These supporters are not insensitive to the social and economic costs associated with major management shifts, but they say the long-term benefits will be worth it. Still, some fishermen, legislators and scientists question whether the policy will work to replenish stocks and whether it is fair to fishermen.
Other scientists, however, find fault with the targets. Brian Rothschild, who oversaw implementation of the original Magnuson–Stevens act for NOAA is now a professor at the University of Massachusetts in Dartmouth. He says that the restoration targets for some troubled species are too high and that the ecosystem isn't equipped to handle maximum levels of all species all the time. "The carrying capacities of ecosystems don't really work that way," he says. Another question is whether catch shares are the best way to achieve mandated population restorations and increased biodiversity. A study published in 2008 analysed a database of more than 11,000 fisheries, 121 of which were managed using some form of catch shares. The study focused mainly on landings data, and looked for drops in catch as a sign of fishery collapse. The authors concluded that those under catch shares were less prone to collapse and that catch shares can halt or even reverse collapse.
Other studies, using different methods, have suggested a more complicated picture. Timothy Essington, a fisheries ecologist at the University of Washington in Seattle, for instance, looked in more detail at 15 catch-share programmes in North America, analysing their effect on fish numbers, the use of habitat-damaging gear and commercial landings. He found that results varied widely between systems, with continued population declines for some fisheries even under catch share management. "It totally depends on the baseline you're looking at," says Essington.
Read the full story in the journal Nature