A new survey conducted by the National Marine Fisheries Service reveals that populations of Alaska pollock, the world’s largest food fishery, have dropped 50 percent since last year. Pollock is America’s most ubiquitous seafood product, found in McDonald’s fish sandwiches, frozen fish sticks, fish and chips, and imitation crabmeat.

The assessment revealed that Bering Sea pollock stocks have declined to their lowest level on record (pdf) a startling development for a fishery NMFS’ chief scientist recently called “one of the most successfully managed species in the world” and that has earned a Marine Stewardship Council certification.

In December, the North Pacific Fishery Management Council will set the new pollock catch limits for 2009. Scientists and conservationists have warned that unless the Council reduces fishing pressure on pollock, a vital forage species for fur seals, whales, and endangered Steller sea lions, the entire Bering Sea ecosystem could be in jeopardy of collapse. This would prove devastating for the state’s commercial fishermen and traditional coastal communities that depend on a healthy ocean for their livelihoods.

“Economic pressures to keep on fishing at such high levels have overwhelmed common sense,” said Dr. Jeremy Jackson, Director of the Center for Marine Biodiversity and Conservation at the Scripps Institution of Oceanography. “With the huge uncertainties inherent in fisheries models, a far more precautionary, ecosystem-based approach is required. Otherwise, fisheries managers are gambling with the health of our oceans and coastal communities.”

Over the past several years, the pollock fishery has experienced poor juvenile survival rates and dwindling populations, forcing the council to reduce harvests in the past two fishing seasons. But experts say these actions have been inadequate, failing to prevent further declines. In order to restore the fishery’s health, the allowable catch must be cut in half, fishing on spawning populations suspended, and marine reserves established to protect critical habitats.

“We are on the cusp of one of the largest fishery collapses in history,” said John Hocevar, Greenpeace Oceans Campaign Director. “It may still be possible to prevent disaster, but the North Pacific Fishery Management Council must take swift and decisive action when they meet in December.”