Forecasting Pink Salmon Abundance in Southeast Alaska from Juvenile Salmon Abundance and Associated Environmental Parameters

November 27, 2010

The Southeast Coastal Monitoring project (SECM) is a component of the NOAA Auke Bay Laboratories salmon research program which has sampled juvenile salmon and associated biophysical parameters in northern Southeast Alaska (SEAK) since 1997 utilizing the NOAA Ship John N. Cobb and chartered trawl vessels. Sampling juveniles as they migrate to the Gulf of Alaska, after high-mortality periods of freshwater incubation and early marine residency, provides information on year-class strength that can be used with associated environmental data to forecast abundance of the fish when they return as adults. Data from these annual surveys have been used to develop models that predicted SEAK pink salmon harvests within 16% of actual harvests for 2004, 2005, 2007, 2008, and 2009. However, this forecast accuracy was not achieved in 2006, when pink salmon harvest was well below both the SECM forecast based on juvenile salmon abundance and the Alaska Department of Fish and Game (ADF&G) forecast based on previous pink salmon harvest time series. Despite this overestimate, the 2006 SECM forecast accurately identified a decline in average pink salmon harvest. The ADF&G is now incorporating the SECM juvenile data into their annual harvest time series forecast.