October 29, 2008

Animal Feed Responsible For One-Third Of World’s Fish Catch

Scientists reported on Wednesday that one-third of the world's ocean fish catch is ground up for animal feed "” a potential problem for marine ecosystems and a waste of a resource that could directly nourish humans.

Anchovies, sardines, menhaden and other small- to medium-sized fish often thought of as bait are being used to feed pigs, chickens and farm-raised fish, researchers wrote in a study to be published in November in the Annual Review of Environment and Resources.

The study said these so-called forage fish account for 37 percent, or 31.5 million tons, of all fish taken from the world's oceans each year. Ninety percent of that catch is turned into fish meal or fish oil, most of which is used as agricultural and aquacultural feed.

"These numbers are staggering", said Ellen Pikitch, executive director of the Institute for Ocean Conservation Science and a professor at Stony Brook University in New York.

"The reason I find that so alarming is that it's an enormous percentage of the world fish catch," Pikitch said. "And fish are fundamentally important to the health of the ocean overall."

The study informed that forage fish are near the base of the marine food web, nourishing larger fish, ocean-dwelling marine mammals and sea birds, especially puffins and gulls.

Pikitch said unlike such dinner-plate fish as tuna, swordfish and cod, the extraction of forage fish is largely unregulated. Excessive removal of these small fish from the ocean environment could hurt the species that feed on them.

She warned that aside from the potential ecological consequences, the taking of these large numbers of forage fish interferes with food security for humans.

It takes three to five pounds (1.36 to 2.27 kg) of fishmeal on average to produce one pound (0.45 kg) of farm-raised fish, Pikitch said.

"If you're creating protein for humans to consume, does it make sense to take three to five pounds of perfectly good food and convert it into only one pound of food?" she said.

Most forage fish are high in omega 3 fatty acids associated with heart health, said Pikitch, adding that it makes sense for humans to consume these fish directly rather than to feed them to livestock and farmed fish.

But human consumption of these fish needs to be monitored, according to Joshua Reichert of the Pew Environment Group.

"Whatever people take out of the sea needs to be carefully calibrated to ensure that sufficient fish are left to sustain populations of other fish, seabirds and marine mammals, which all play a major role in the healthy functioning of the world's oceans," Reichert said.

The Pew Institute for Ocean Science, which is transitioning to become the Institute for Ocean Conservation Science at Stony Brook, funded the study.


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