Production of coho salmon from the Unuk River, 1997-1998
By: by Edgar L. Jones III, Scott A. McPherson and Amy B. Holm.
Contributors: McPherson, Scott A.; Holm, Amy B.; Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 99-43.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish
Published: 1999
Place of publication: Anchorage
Language: eng
Number of pages: 42
Subjects: Coho salmon -- Alaska -- Unuk River -- Statistics.; Fish tagging -- Alaska -- Unuk River -- Statistics.; Fish populations -- Alaska -- Unuk River -- Statistics.
Genres: Statistics.
Description: Recovery of coded wire tags from adult coho salmon Oncorhynchus kisutch in 1998, tagged as smolt in 1997, was used to estimate smolt abundance, harvest, exploitation rate, and production from the Unuk River, near Ketchikan, Alaska. Baited G-40 minnow traps were fished daily on the Unuk River from 28 March through 18 April 1997. During this period 11,357 coho salmon smolt 70 mm fork length (FL) were tagged and released alive with valid tags having codes 04-43-35 and 04-43-36. Sampled smolt averaged 84mm FL and 5.5 g in weight. In 1998, 149 adult coho salmon were recovered bearing coded wire tags, 139 of which were random fishery recoveries. These random recoveries represent an estimated harvest of 45,388 (SE = 7,461) coho salmon in U.S. marine waters. Of this harvest, the troll fishery took an estimated 57%, seine fisheries took 10%, drift gillnet fisheries took 20%, and recreational fisheries took 13%. An estimated 12,422 (SE = 3,298) adults escaped into the Unuk River, as determined by a mark-recapture study coupled with a radiotelemetry study. Estimated total run (i.e., escapement plus harvest) in 1998 for all coho salmon bound for the Unuk River was 57,811 (SE = 8,158); marine exploitation rate on this run was an estimated 79% (SE = 5.3%). Contribution of Unuk River coho salmon to the Ketchikan marine sport fishery was about 20% of the estimated harvest in that fishery. Smolt abundance in 1997 was 809,677 (SE = 189,345), as determined using Chapmans modification of the Peterson estimator, and the estimated marine survival rate was 7.1% (SE = 2.0%).
Notes: "December 1999."

Includes bibliographical references (p. 24-25).

Also issued online.