Fisheries, Subsistence, and Habitat
Publications Searchable Database
Search Again| Division: | Sport Fish |
| Title: | Stock assessment of rainbow trout in the upper Kenai River, Alaska, 2018. |
| Author: | Eskelin, T., and A. Reimer. |
| Year: | 2023 |
| Report ID: | Alaska Department of Fish and Game, Fishery Data Series No. 23-13, Anchorage. |
| Abstract: | A multiple-event mark–recapture study was conducted on rainbow trout (Oncorhynchus mykiss) in the upper Kenai River in 2018. The objectives of this study were to estimate the abundance and fork length (FL) composition of rainbow trout in the most heavily fished section of the upper Kenai River (river miles 69.6–73.2) and to compare these estimates to those from previous surveys conducted in 1986, 1987, 1995, 2001, and 2009 on the same stretch of river. There were an estimated 10,568 (SE 608) rainbow trout at least 200 mm FL and 8,482 (SE 495) rainbow trout at least 300 mm FL in the study area. Abundance of fish at least 200 mm FL was 79% higher than in 2009 and 24% higher than in 2001. Abundance of fish at least 300 mm FL was 66% higher than in 2009, 33% higher than in 2001, and 52% higher than in 1995. Most of the rainbow trout were between 250 mm and 449 mm FL, accounting for 88% of the population. Approximately 75% of the population was less than 400 mm FL, which is the approximate upper length (16 inches total length) of fish allowed to be harvested by regulation. Overall, rainbow trout abundance in 2018 was considerably higher than in any other study year, but the number of fish more than 450 mm FL was only 743 (SE 71), which was less than half of what was observed in 1995, 2001, and 2009. |
| Keywords: | rainbow trout, Oncorhynchus mykiss, abundance, MARK, RMark, Huggins models, fork length, Kenai River, mark–recapture |