Bristol Bay sockeye salmon forecast down 21 percent
By Margaret Bauman
Alaska Journal of Commerce
State biologists are forecasting a total run of fewer than 34 million sockeye salmon in Bristol Bay in the summer of 2009, down 21 percent from runs averaging 43 million reds over the past five years.
Bristol Bay fisheries researchers said the lower forecast for 2009 is not unexpected, given that ocean temperatures have been colder in the North Pacific for the past two years. Colder temperatures usually result in reduced marine survival of sockeye salmon, but researchers said they are uncertain how recent colder water will affect overall return of sockeyes to Bristol Bay this summer.
The predicted run of 33.8 million sockeyes is 4 percent lower than the previous 10-year mean of total runs of 35.23 million reds. All systems within Bristol Bay are expected to exceed minimum spawning escapement goals.
A run of 33.78 million sockeyes can potentially produce a total harvest of 25 million fish if escapement goals are met for managed stocks and processors are capable of taking the surplus fish. The projected harvest includes a harvest of 23.99 million fish in Bristol Bay and 1.05 million reds in the South Peninsula fisheries.
A Bristol Bay harvest of 23.99 million sockeyes would be 8 percent higher than the previous 10-year mean of 22.2 million.
Researchers also broke down the forecasted run by district and river systems, including 12.11 million to the Naknek-Kvichak district, 9.59 million to the Egegik district, 2.38 million to the Ugashik district, 8.93 million to the Nushagak district and 0.77 million to the Togiak district.
Predictions for each age class of reds returning to a river system are calculated from models based on the relationship between adult returns and spawners or siblings from previous years.
Similar methods have been used to produce the Bristol Bay sockeye salmon forecast since 2001. There has been a tendency for the forecasts and projected harvests to be biased low in recent years, including the 2008 forecast, which was 4 percent below the total run.
Forecasts since 2001 have averaged 9 percent below the actual total run, while expected harvests have averaged 5 percent below actual harvests since 2001.
Although there is great variability around the forecasts for individual river systems, the overall baywide forecasts have been fairly accurate since 2001, researchers said.
Margaret Bauman can be reached at margiebauman.@alaskajournal.com.
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