Document Type
Thesis
Abstract
Blue Lake is a multiple-use reservoir near Sitka, Alaska that supports an important sport fishery sustained by a reproducing population of rainbow trout Oncorhynchus mykiss. Although harvest levels appeared high, the effects of exploitation were unknown before this study took place. Mark-recapture, size-age-sex, maturity, and harvest data were collected during 1991 and 1992 to assess stock status. Closed population abundance estimators proved more useful than open population models. Abundance in spring 1992 was estimated at 4708 fish >180 mm FL with a coefficient of variation of 17.0%. Maximum scale age was 7, age- and length-at-maturity at the 50% level were 3.4 years and 233 mm FL, natural mortality was 0.26, and full recruitment occurred at age 5. The critical exploitation rate beyond which sustained yield may not be possible was estimated at 0.32. The estimated 1992 exploitation rate with hooking mortality taken into account was 0.26.
Publication Date
5-17-1994
Recommended Citation
Der Hovanisian, John A., "Stock assessment of rainbow trout in a Southeast Alaska impoundment" (1994). Fisheries . 376.
https://ualaska.researchcommons.org/uaf_fisheries_facpubs/376
Handle
http://hdl.handle.net/11122/14752