Another modeling "oops": Carbon dioxide fails to prevent 22-fold increase in Fraser River salmon run

Canada sees shock salmon glut : Nature News

It's the biggest run of sockeye salmon in British Columbia since 1913. Some 34 million fish are thronging the Fraser River as they return from the sea to spawn, federal regulators announced on 31 August. The event, following two decades of decline in salmon-run numbers, is taking fisheries scientists by surprise — and causing frustration across the fishing industry, which is largely unable to access the windfall.
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This year's unexpected boom has led to even more intense speculation about the state of the sockeye population. The 2009 salmon run reportedly saw only around 1.5 million fish returning to the river. The Canadian government's Cohen Commission, established in 2009, is now looking at the current state of the sockeye population and potential causes of the decline. The commission aims to make recommendations for the future sustainability of salmon stocks by mid-2011.

Given the existence of models that predict fluctuations in salmon populations, why has this year's glut come as such a shock? Fisheries and Oceans Canada, the government agency in Ottawa, Ontario, that runs the models and regulates the salmon fishing industry, has been criticized for failing to predict it.

Sue Grant, fisheries biologist at Fisheries and Oceans Canada, explains that the models are full of uncertainties: "They are based on biological information from historical and real-time catches to estimate the abundance," she says. "The forecasts are probability distributions based in part on extrapolation from historical data sets."

Flashback - Canadian report says Fraser River salmon fishery in danger of collapse

VANCOUVER, British Columbia (AP) -- The Fraser River salmon fishery could collapse within a few decades because of global warming, a Canadian government study indicates.

The report issued this week by the Climate Change Secretariat predicts a grim future for the world's most productive sockeye salmon river system, which historically has produced millions of fish caught in U.S. as well as Canadian waters.