Northern Cook Inlet Management Area
Deshka River Salmon Weir
The goals for the Deshka River project are to count the chinook and coho salmon escapements and estimate the age, sex, and size composition of the escapements. This information is used by fishery managers to assess the chinook and coho run strength in-season and set appropriate fishery regulations. During June through September each year a weir is operated at rivermile 7 of the Deshka River to count salmon and capture a sample of fish.
Susitna River Chinook Salmon Abundance
Technicians measure and tag a Chinook salmon at the mainstem Susitna River fishwheel camp. In addition to applying a dart tag primary mark, a operculum (gill cover) punch is used as a secondary mark to asses tag loss of the dart tags.
Recent Alaska-wide downturns in productivity and abundance of Chinook salmon stocks have created social and economic hardships across many communities in rural and urban Alaska. There is a fundamental need to more precisely characterize productivity and abundance trends of Chinook salmon stocks across Alaska, gather essential information necessary to understand root causes of these widespread declines, and track population trends into the future. The Susitna River was selected by ADF&G as a Chinook salmon indicator stock, with estimation of the inriver run size in the mainstem Sustina and Yentna Rivers being recommended stock assessment projects. In 2017, Sport Fish staff from Palmer will continue estimating abundance of Chinook salmon in the Yentna River drainage, and in the mainstem Susitna River above the confluence with the Yentna River. Abundance will be estimated using a mark-recapture study. This approach involves capturing salmon in fish wheels in the lower Susitna River and tagging the fish with a dart tag, which looks like a piece of colored plastic tubing about 6 inches long. More fish wheels, further upstream, capture salmon so they can be inspected for tags.
Susitna River Chinook Salmon Distribution
In addition to estimating abundance, the spawning distribution of Chinook salmon in the Susitna River drainage will continue to be assessed using a radio-telemetry study. Radio transmitters will be inserted into 600 Chinook salmon in the Susitna River drainage in 2017. A combination of fixed stations and aerial surveys will be used to detect unique radio signals as fish migrate to their natal spawning streams. Data collected will enhance knowledge of the spawning distribution and habitat use and quantify the annual variation in distribution.