Production of coho salmon from the Taku River, 1994-1995
By: by Scott A. McPherson and David R. Bernard.
Contributors: Bernard, David R.; Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 96-25.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish, Research and Technical Services
Published: 1996
Place of publication: Anchorage
Language: eng
Number of pages: 40
Subjects: Coho salmon -- Taku River (B.C. and Alaska) -- Statistics.; Fish populations -- Taku River (B.C. and Alaska) -- Measurement.; Fishes -- Taku River (B.C. and Alaska) -- Statistics.
Description: As part of an ongoing study of the production of coho salmon Oncorhynchus kisutch from Taku River, near Juneau, Alaska, the Division of Sport Fish implanted coded wire tags in smolt leaving the river in spring 1994. Subsequent recovery of these fish was used to estimate the harvest, production, exploitation rate in 1995, and abundance of smolt in 1994. In 1994, two 12' diameter and two 8' diameter rotary smolt traps were fished near Canyon Island on the Taku River. Of 12,124 coho salmon smolt caught from 1 May to 25 June, 11,446 were coded wire tagged and released (5,334 with tag code 04-42-09, 5,149 with tag code 04-42-10, and 963 with tag code 04-42-11). Smolt sampled from the catch averaged 101 mm fork length and were 65% age 1.0 and 35% age 2.0. In 1995, 201 adult coho salmon bearing coded wire tags implanted near Canyon Island were recovered in random sampling of marine fisheries to produce an estimate of total marine harvest of 111,571 (SE = 12,186). Of this harvest, the troll fishery took an estimated 40%, drift gillnet fisheries took 51%, seine fisheries 1%, and recreational fisheries 7%. A mark-recapture experiment partially funded by Sport Fish Division was conducted by the Commercial Fisheries Management and Development Division and the Canadian Department of Fisheries and Oceans to estimate the inriver run of coho salmon past Canyon Island using a Darroch estimator. Estimated abundance was 69,448 (SE = 3,244) fish, of which 13,738 were harvested by inriver fishers above the U.S./Canada border, and escapement past all fisheries was estimated to be 55,710. The estimated total run, the sum of escapement and harvest, in 1995 for coho salmon originating above Canyon Island was 181,019 (SE = 12,610) and the marine exploitation rate was an estimated 62% (SE = 3%). The estimated total run in 1995 for coho salmon from the entire Taku River drainage was 232,076 (SE = 16,167), accounting for those fish originating below Canyon Island. The contribution of Taku River coho salmon (after accounting for fish below Canyon Island) to the Juneau marine sport fishery was an estimated 10,073 fish or 66% of the total estimated harvest in that fishery. The estimated smolt abundance in 1994 from above Canyon Island was 1,525,330 (SE = 339,822) using a modified Petersen estimator, and marine survival of coho salmon smolt from above Canyon Island was estimated at 12% (SE = 3%).
Notes: "September 1996"

Includes bibliographical references (p. 21-23).

Also issued online.