Estimated harvest of coho salmon of Kenai River origin in commercial fisheries of upper Cook Inlet, Alaska, 1993-1994
By: by Jamie A. Carlon and James J. Hasbrouck.
Contributors: Hasbrouck, James J.; Alaska. Division of Sport Fish. Statewide Research and Technical Services Unit.
Series: Fishery data series -- no. 96-7.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish, Research and Technical Services
Published: 1996
Place of publication: Anchorage, Alaska
Language: eng
Number of pages: 55
Subjects: Coho salmon -- Alaska -- Kenai River -- Statistics.; Fishery resources -- Alaska -- Kenai River -- Statistics.; Salmon fisheries -- Alaska -- Kenai River -- Statistics.
Description: The 1994 commercial harvest of coho salmon of Kenai River origin by Upper Cook Inlet fisheries was estimated based on the recovery of harvested adults marked with coded wire tags. In the Central District, an estimated 11,732 (SE = 746) coho salmon were harvested by the drift gillnet fishery and 14,673 (SE = 1,261) were harvested by the Upper Subdistrict (eastside) set gillnet fishery, for a total of 26,405 (SE = 1,465) coho salmon. These harvests represent 4% of the total drift gillnet harvest of 303,935 coho salmon and 21% of the total eastside set gillnet harvest of 69,281 coho salmon. Harvest estimates for the 1993 commercial fisheries were revised for comparison with 1994 estimates. In 1993, an estimated 930 (SE = 194) coho salmon of Kenai River origin were harvested by the drift gillnet fishery and 6,806 (SE = 750) were harvested by the eastside set gillnet fishery, for a total of 7,736 (SE = 775) coho salmon harvested in the Central District. These harvests represent 1% of the total drift gillnet harvest of 121,785 and 16% of the total eastside set gillnet harvest of 43,075. Geographic and temporal trends in harvest were similar to those occurring in 1994. The harvest of coho salmon of Kenai River origin relative to the total harvest was lower than expected in both 1993 and 1994. The commercial harvest of coho salmon of Kenai River origin was substantially lower than the estimated inriver sport harvest of 86,700 fish in 1994 and 50,500 in 1993. Prior to 1993, it was assumed that the number of coho salmon from the Kenai River harvested commercially was substantially greater than the inriver sport harvest. The most abundant group of marked coho salmon returning to the Kenai River in 1994 was the cohort marked as smolt at the Moose River in 1993. The proportion of the entire Kenai River return marked at the Moose River was 0.1016. This proportion, which was estimated by examining the inriver recreational harvest, was used to estimate harvest by commercial fisheries. The marked proportion remained relatively constant over the duration of the recreational fishery during August and September, indicating that smolt emigrating from the Moose River were a representative sample of coho salmon from the Kenai River with respect to return timing. The Moose River is therefore a practical site for marking smolt in the future. Based on the marked proportion, the number marked, and the number of adults examined for marks, the number of coho salmon smolt emigrating from the Kenai River in 1993 was about 978,000 (SE = 39,407) and the estimated smolt emigration in 1992 was over 879,000 (SE = 42,607). This estimate is biased somewhat high due to long-term tag loss. However, the estimated smolt-to-adult tag loss was low (2%). Multiple headmold sizes used to tag fish in 1993 allowed placement of tags to be more precise and perhaps improved tag retention rates over groups of fish tagged and released in prior years.
Notes: "March 1996"

Includes bibliographical references (p. 36-38).

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