Enumeration of the 1996 Harrison River chinook salmon escapement

In 1985, the Pacific Salmon Treaty committed the Canadian Department of Fisheries and Oceans to halt the decline in abundance of chinook salmon, (Oncorhynchus tshawytscha) stocks. The Harrison River was designated a chinook indicator stock, and escapement has been monitored annually since 1984. In 1996, 1,894 marks were applied and 160 were recovered in a recovery sample of 4,916 chinook. Sex based biases were observed in the application and recovery samples. No other significant biases were detected. The escapement estimates derived by sex were 19,214 adult males, 18,180 adult females, and 39,840 precocious males. The total adult escapement estimate (37,394) was the third lowest since monitoring began in 1984. Revisions of sampling technique to reduce handling stress associated with recaptures and to improve indentification of adult and precocious males are suggested. Although no bias was detected, the age composition of the escapement estimate may be biased as a result of the theft of scale samples.