World Food Supply & Oceans Threatened by Fish Farming

An article in this week’s Science Magazine co-authored by Dr. Rebecca Goldburg of the Environmental Defense Fund (EDF) finds that some forms of fish farming actually reduce rather than increase ocean resources. Written by an international group of scientists, “Nature’s Subsidies to Shrimp and Salmon Farming” details how some farmed species increase pressure on wild fisheries and, in fact, may reduce the world’s overall food supply.

“The boom in shrimp and salmon farming is hurting our oceans,” said Dr. Goldburg. “On the farm, shrimp and salmon are fed a diet containing large quantities of wild-caught fish. For example, 2.8 pounds of wild-caught fish are required to produce one pound of farmed salmon. Farm-raising salmon is like farm-raising tigers. They will always eat more flesh than they produce.”

As recently as the early 1980’s, virtually all shrimp and salmon were wild caught. Now, farms supply almost half of the salmon and about a quarter of the shrimp consumed worldwide, and roughly a third of the salmon and half the shrimp consumed in the United States.

“While many fisheries stocks around the world have declined alarmingly, shrimp and salmon farming continues to expand, literally eating into wild fish populations,” said Goldburg.

The Science article also examines the impact of salmon and shrimp farming on coastal ecosystems, which provide critical habitat for fish and other marine animals.

“Creation of coastal shrimp ponds destroys mangrove forests and other wetlands that are crucial to the health of ocean fisheries. Shrimp and salmon farms discharge untreated effluents laden with polluting nutrients, pesticides, and other chemicals directly into ecologically fragile coastal waters,” said Goldburg.

“Most consumers are not aware of the ecological costs of their shrimp cocktails and salmon steaks, and producers do not pay these costs,” said Goldburg. “Incentives provided through regulation, reduced financial subsidies, and altered trade policies are urgently needed to end environmental degradation by shrimp and salmon farming.”