"Pink Salmon"

A database describing a 67-year time series for Sashin Creek pink salmon (Oncorhynchus gorbuscha) data is presented. The database details the survival and other biological parameters of the pink salmon population living in Sashin Creek, a pristine environment in Little Port Walter, Baranof Island, Alaska. We assembled all the published and unpublished biological and environmental data pertaining to this population, which has been evaluated almost continually by researchers since 1934. We developed a database using Microsoft Access that includes annual estimates of the freshwater and saltwater survival for these fish. The database contains the daily counts of the number of emigrating fry and escaping adults during their annual migrations since 1934, and their lengths, weights, or fecundity. Environmental parameters in the database include stream temperature, stream discharge, daily minimum and maximum air temperatures, and precipitation where Sashin Creek enters seawater at Little Port Walter. All records have been evaluated and transformed to ensure comparability. References for all data are provided, including unpublished sources. The Sashin Creek Weir Database (SCWDATA) can be accessed through the Internet.

This annual survey, conducted by the Southeast Coastal Monitoring (SECM) project, marks 20 consecutive years of systematically monitoring how juvenile salmon utilize marine ecosystems during a period of climate change.

The 2013 Salmon forecast - model selection included a review of Alaska ecosystem indicator variables and considered additional biophysical parameters to improve the simple single-parameter juvenile CPUE forecast model.

NOAA Fisheries supports the Southeast Alaska Coastal Monitoring program, which studies juvenile salmon in the coastal waters of the Gulf of Alaska ecosystem.

Southeast Alaska Coastal Monitoring project survey data on Juvenile Salmon in the Marine Waters of Southeastern Alaska.

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.

The Southeast Alaska Coastal Monitoring (SECM) project has been sampling juvenile salmon (Oncorhynchus spp.) and associated environmental parameters in northern Southeast Alaska (SEAK) since 1997 to better understand effects of environmental change on salmon production. A pragmatic application of this effort is to forecast the abundance of adult salmon returns in subsequent years. Since 2004, juvenile peak salmon catch per unit effort (CPUE) from SECM, modified by other environmental parameters as appropriate, has been used to forecast harvest of adult pink salmon (O. gorbuscha) in SEAK. The forecast of 16.1 million fish for 2008 was within 2% of the actual harvest of 15.9 million fish. This represents the fourth forecast over the period 2004-2008 which was within 11% of the actual harvest. In 2006, however, the harvest was substantially different from the forecast. Although a simple CPUE model did indicate a downturn in harvest for 2006, the forecast was nonetheless 200% higher than the actual 2006 harvest. These results show that the CPUE information has great utility for forecasting year class strength of SEAK pink salmon, but additional environmental data are needed to avoid “misses” such as the 2006 return. Since 2007, the forecast model was developed using stepwise multiple regression, jackknife hindcast analysis, and bootstrap confidence intervals. A four-parameter model was selected as the “best” forecast model for 2009. Juvenile pink salmon CPUE in northern SEAK accounted for 82% of the variability in annual harvest of SEAK pink salmon over the 1997-2008 time period. The amount of variability explained was improved to 99% when the May 20-m integrated sea water temperatures and mixed-layer depths (from the SECM strait habitat) and the El Niño Southern Oscillation (ENSO) Index were included in the four-parameter multiple regression model. The 2009 forecast from the four-parameter model, using data collected in 2008, is 44.4 million fish, with an 80% bootstrap confidence interval of 37-52 million fish. Juvenile pink salmon peak CPUE collected in southern SEAK from 2005-2007 was highly correlated (r = 0.99) with the peak CPUE from northern SEAK in those years, and was not correlated (r < 0.01) with the residuals from the forecast model. Because the pattern of juvenile abundance was similar for the two areas, no additional variation in the harvest was explained by including the southern region data. However, that time series includes only three years of data; more years may provide additional information on regional variation in pink salmon year-class strength, especially for years when the two areas have distinctly different environmental conditions.