The catch of small, schooling fish such as sardines and anchovies should be cut in half globally and the amount left in the ocean doubled to protect the ecologically vital species from collapse, scientists say in a new report.
The silvery species known as forage fish are harvested in huge numbers worldwide and are easy for fishermen to round up because they form dense schools, or "bait balls." But wide fluctuations in their numbers make them especially vulnerable to overfishing, according to the report released Sunday by the Lenfest Forage Fish Task Force, a 13-member panel of scientists from around the world.
The report urges wildlife managers to take more precautions to prevent future declines. The analysis estimates that small fish such as herring and menhaden are twice as valuable in the water as in a net because so many larger fish, including tuna, salmon and cod, rely on them for food.
"As the forage fish decline in abundance, so go their predators," said Ellen Pikitch of the Institute for Ocean Conservation Science at New York's Stony Brook University, the head of the panel, which is funded by a nonprofit grant.
The findings are the latest to raise concerns about the harvest of the little, oily fish, given their role as food for the ocean's bigger fish as well as dolphins, whales and seabirds.
Forage fish account for more than one-third of catches globally, the report says, with most of the yield ground into meal and fish oil to feed farmed fish and livestock and to produce nutritional supplements.
And although their large schools suggest the supply of such fish is vast and limitless, Pikitch said, "demand and price is increasing while their crucial ecological role has largely been ignored."
The scientists conducted a worldwide analysis of the science and management of forage fish, studying an assortment of fisheries including anchovetas in Peru and California's sardines.
California's booming sardine fishery famously collapsed in the mid-20th century. Although it has since rebounded, scientists are still studying exactly what combination of overfishing and shifting environmental conditions brought the decline.
The report's recommendations, likely to face resistance from the $5.6-billion industry, echo a recent push by environmental groups for new protections on forage fish.
A bill before the California Legislature would require the state to leave more small fish in the water for natural predators to feed on. Last year, the conservation group Oceana sued the federal government to tighten protections for anchovies and sardines fished off the coasts of California, Oregon and Washington.
Still, the U.S. West Coast is ahead of other parts of the world in how it manages some forage fish, scientists on the panel said. The sardine catch, for instance, is subject to stricter monitoring and more conservative limits that could serve as a buffer against future crashes.
California's most valuable catch, squid, is also considered a forage fish but was not included in the analysis.