Fisheries, Subsistence, and Habitat
Publications Searchable Database
Search Again| Division: | Sport Fish |
| Title: | Abundance of adult coho salmon in the Kenai River, Alaska, 2004 |
| Author: | Massengill, R.L., and D. Evans |
| Year: | 2007 |
| Report ID: | Alaska Department of Fish and Game, Fishery Data Series No. 07-85, Anchorage. |
| Abstract: | A two-event mark-recapture study conducted throughout August and September 2004, produced the sixth consecutive estimate of adult coho salmon abundance in the Kenai River. Two fish wheels were used in the marking event to capture fish near rkm 45. Fish were tagged primarily with spaghetti tags; a sub-sample was radio-tagged and tracked to estimate the portion of all tagged fish that survived tagging and sustained upstream migration. For the recapture event, drift gillnets were deployed from boats between rkm 48.9 and 58.4. Estimated abundance of adult coho salmon was 118,383 (SE = 9,000). Aggregating this estimate with the estimates representing the number of incidental marking mortalities, the inriver sport harvest downstream from the marking locations, the personal-use harvest, and the UCI commercial harvest allowed for total run reconstruction for 2004 of 184,436 (SE = 13,948). Deducting estimated upstream sport harvest from estimate of live abundance produced an estimate of escapement for 2004 of 95,394 (SE = 9,394). The 2004 harvest rate was estimated as 0.47 (SE = 0.14), and the smolt-to-adult (marine) survival rate was estimated as 0.15 (SE = 0.01. Estimates of harvest rate for 1999-2004 and recent implementation of additional fishery restrictions suggest that there is no immediate threat to the sustainability of the population or the fisheries it supports and that a harvestable surplus exists most years. Historic information suggests that cumulative fish wheel catch rates may be used to discern weak runs from strong. |
| Keywords: | coho salmon, Oncorhynchus kisutch, Kenai River, mark-recapture, abundance, escapement, fish wheel, drift net, radio telemetry |