The scientists’ computer model accurately predicted that 221,000 fish would return in 2011. The model came up just shy in 2012, predicting almost 180,000 fish would return; the actual number was 203,000 returning results.
Results suggest that managing Pacific salmon effectively requires many types of information and no single indicator can represent the complexities of a salmon’s life when it first enters the ocean. Moreover, the indicators that best describe one stock or species may differ from those that best describe another stock or species. For example, the researchers found that the importance of indicators in May of a Chinook’s first year in the ocean were quite different from those just a month later in June.
“The ocean has historically been viewed as a ‘black box’ in the life of a salmon,” said NOAA scientist Brian Burke, the study’s lead author, “but this study opens that box just a little and shines an important scientific light on its contents.”
He said managers can take advantage of this information in forecasting the size and timing of Chinook returns to the Columbia River basin, a particularly challenging task because harvest limits are typically set some months before the season starts.
The study, “Multivariate Models of Adult Pacific Salmon Returns,” was published online in PLoS ONE http://dx.plos.org/10.1371/journal.pone.0054134.