Spawning abundance of chinook salmon in the Taku River in 1997
By: by Scott A. McPherson ... [et al.].
Contributors: McPherson, Scott A.; Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 98-41.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish
Published: 1998
Place of publication: Anchorage
Language: eng
Number of pages: 23
Subjects: Chinook salmon -- Alaska -- Taku River -- Statistics.; Fish tagging -- Alaska -- Taku River -- Statistics.; Fish populations -- Alaska -- Taku River -- Statistics.; Chinook salmon -- Spawning.
Genres: Statistics.
Description: A cooperative study involving the Alaska Department of Fish and Game, the Taku River Tlingit First Nation, and the Canadian Department of Fisheries and Oceans was conducted to estimate the number of spawning chinook salmon Oncorhynchus tshawytscha in the Taku River in 1997 with a mark-recapture experiment. Fish were captured at Canyon Island on the lower Taku River with fish wheels from May through August and were individually marked with back-sewn, solid-core spaghetti tags. All tagged fish were also batch marked with an opercle punch plus removal of the left axillary appendage. Sampling on the spawning grounds in tributaries was used to estimate the fraction of the population that had been marked. Spawning abundance of medium-size chinook salmon (401659 mm long; mid-eye to fork of tail) was estimated to be 2,543 (SE = 926). Estimated spawning abundance of large-size fish (=660 mm) was 114,938 (SE = 17,888), and the estimated total of medium and large fish was 117,481 (SE = 17,912). The aerial survey counts of large spawners conducted on some of the Taku River tributaries was 12% of the mark-recapture estimate, which was approximately one-half of the fraction counted in similar studies during 1989, 1990, 1995 and 1996. The 1991 brood year (age 1.4) constituted an estimated 60% of the age-.2 to age-.5 spawning population, followed by the 1992 brood year (mostly age 1.3), which constituted an estimated 37% of the estimated population.
Notes: "December 1998".

Includes bibliographical references (p. 14-15).

Also issued online.