Abundance and movement of the rainbow trout spawning stock in the upper Naknek River, Alaska
Schwanke CJ. 2002. Abundance and movement of the rainbow trout spawning stock in the upper Naknek River, Alaska. University of Wyoming
Native rainbow trout Oncorhynchus mykiss in the Naknek River of Southwest Alaska attain large sizes and support a popular recreational fishery. I studied the dynamics of the spawning stock during 2000 and 2001. Three methods of capturing spawning fish were assessed; the length structures and sex ratios of spawning fish were described; mark-recapture estimates of the number of spawning fish were conducted; and movements of fish following spawning were determined. I found that drifting gill nets and beach seines were efficient sampling gears, but hook and line was inefficient and biased toward immature fish. Median fork lengths of spawning fish were 640 mm for females and 697 mm for males with fish up to 860 mm in the samples. There were about 3,000 spawning fish in the Naknek River during each year of the study. Eighty percent of radio-tagged fish moved from the river upstream into Naknek Lake following spawning and most of these fish returned to the river in the fall. This information can be used in future monitoring of the spawning stock and assessment of the effectiveness of sport fishing regulations.
- Type
- Academic
- Authors
- Schwanke, Craig
- Date of Issue
- 2002-05
- Publisher
- University of Wyoming
- Units
- KATM
- Keywords
- Abundance, Fish, migrate, Naknek river, Oncorhynchus mykiss, Population, Rainbow Trout, Southwest Alaska, Spawning, Sport Fishing, Thesis