Kvichak river sockeye salmon stock status and action plan, 2003

Alaska Department of Fish and Game

In response to guidelines established in the "Sustainable Salm on Fisheries Policy" (ADF&G 2000), the Department recommended the Kvichak River sockeye salmon stock as a stock of concern in January 2001. The Board of Fisheries found that the stock met the criteria and classified Kvichak River sockeye salmon as a stock of "yield" concern" at that time. This classification is based on the definition of "yield concern" found in the policy. A "yield concern" is "a concern arising from a chronic inability, despite the use of specific management measures, to maintain expected yields, or harvestable surpluses, above a stock's escapement needs". For this determination, the most recent 5-year period (one salmon life cycle or generation) was compared to the Kvichak River data set from 1956 to 1996 (Table 1). This Board cycle, with 3 more years of return data, and failing to meet the minimum biological escapement goal in each of those years, the Department is recommending the Kvichak River sockeye to be elevated to a stock of "management concern". Management concern is defined in the policy as "a concern arising from a chronic inability, despite the use of specific management measures, to maintain escapements for salmon stocks within the bounds of the BEG". A management concern is more severe than a yield concern. Using the most recent 5-year data set, yields and escapements from 1999 and 2000 were compared to pre-peak and peak years only, and yields and escapements from 2001, 2002 and 2003 to off-cycle years only. The high degree of variability over the 40-year span of the data set reflects the long-term cycles coinciding with changes in the Pacific Decadal Oscillation (Hare et al. 1999). It is plausible that the PDO is in the process of shifting to a less productive period for Bristol Bay salmon. The literature states that major PDO regimes have persisted for 20 to 30 years, the most recent shift occurring in 1976-77 and resulting in a period of high productivity for Bristol Bay salmon. A shift to a less favorable regime might suggest that Kvichak River returns of the last 8 years are expected and that higher yields might not be sustainable. If a PDO shift is occurring, this comparison of recent yields is better illustrated by using the entire Kvichak River data set (1956-98) than by using a recent 20-year data set (1978-98).

Kvichak river sockeye salmon stock status and action plan, 2003

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