Sockeye salmon escapement to Windfall Lake during 1997
By: by Richard J. Yanusz.
Contributors: Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 98-32.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish
Published: 1998
Place of publication: Anchorage, Alaska
Language: eng
Number of pages: 30
Subjects: Sockeye salmon -- Alaska -- Windfall Lake.
Other titles: Federal aid in sport fish restoration (Alaska)
Description: A weir was operated on Windfall Creek from 1 June through 17 August 1997, and the escapement was estimated to be 2,426 (SE = 39) sockeye salmon Oncorhynchus nerka. Age 1.3 sockeye salmon that averaged 586mm (SE = 25mm) mid-eye to tailfork length composed 74% (SE = 1.5%) of the escapement, followed by sockeye salmon age 1.1 that averaged 349mm (SE = 16mm) in length that composed 11% (SE = 1.2%) of the escapement. Minimal numbers of sockeye salmon inspected at the weir exhibited scars that might be attributed to commercial fishing gear. A series of foot surveys in the index area during 1997 resulted in a peak count of 484 sockeye salmon, which represented only 22% of the escapement. In a previous study, 46% of the escapement was observed in the index area. A mark-recapture experiment was conducted independently of the weir operations, to test the feasibility of this method for escapement estimation. The estimated escapement of 4,228 (SE = 954) sockeye salmon was 73% greater than the weir count, in part because 28% of the tagged fish never migrated to the recapture site. Limnological sampling was conducted in Windfall Lake and the euphotic zone depth was estimated to be 3.1m (SE = 0.01) and the mean seasonal biomass of macrozooplankton was estimated to be 103mg/m2 (SE = 3.8). Applying the limnological observations to a model of sockeye salmon production, it was estimated that the maximum annual production for Windfall Lake is 1,722 adult sockeye salmon.
Notes: "November 1998"

Includes bibliographical references (p. 19-20).

Also issued online.

Partially financed by the Federal Aid in Sport Fish Restoration Act Project F-10-5, Job No. S-1-13."