Fisheries, Subsistence, and Habitat
Publications Searchable Database
Search Again| Division: | Sport Fish |
| Title: | Abundance and length composition of cutthroat trout at Neck Lake, Southeast Alaska, 2018. |
| Author: | Schwanke, C. J., and A. Reimer. |
| Year: | 2023 |
| Report ID: | Alaska Department of Fish and Game, Fishery Data Series No. 23-46, Anchorage. |
| Abstract: | The population status of cutthroat trout Oncorhynchus clarkii at Neck Lake in Southeast Alaska that was last examined from 1996 through 1998 was reexamined in 2018. Mark–recapture was used to estimate abundance, length composition, and catch per unit effort (CPUE) for fish captured in baited hoop traps, baited funnel traps, and with hook and line. The 2 studies were compared to assess changes to the cutthroat trout population since 1996, when hatchery coho salmon O. kisutch fry commenced rearing in the lake. Estimated abundance of cutthroat trout >180 mm fork length (FL) in 2018 was 4,959 fish (95% CI 4,325–5,726), ~1,800 fish more than estimated in 1998. Length composition estimates of fish >180 mm FL showed larger fish in 2018 with mean lengths of 230 mm FL (SE = 1.3) in 2018 and compared to 219 mm FL (SE = 0.9) in 1998. In 2018, CPUE estimates by gear type for cutthroat trout >180 mm FL were 2.9 and 5.4 fish per overnight set for baited hoop and funnel traps, respectively. Hook and line CPUE was 3.8 fish per hour. Hook and line captured the largest mean size of fish (250 mm FL, SE = 1.6), whereas baited funnel traps caught the smallest mean size of fish (219 mm FL, SE = 1.5) >180 mm FL. Catch data was also used to examine the utility of conducting rapid stock assessments for monitoring cutthroat trout populations in lakes throughout Southeast Alaska. Estimating the proportion of the population above the regionwide minimum size limit and other length composition estimates are probably possible with a single trip of significantly shorter duration than the 10-day period conducted in 2018. An estimate of abundance will continue to require 2 trips, although both trips could be of shorter duration with refined capture gear and techniques. |
| Keywords: | Southeast Alaska, Prince of Wales Island, Neck Lake, cutthroat trout, Oncorhynchus clarkii, abundance, mark-recapture, length composition, coho salmon, Oncorhynchus kisutch, stocking |