Kodiak Management Area
Fishing Research - Chinook
Karluk River, located approximately 72 air miles from the city of Kodiak, has the largest steelhead Oncorhynchus mykiss catch in western Alaska. Historically, the only indicators of abundance have been weir counts of outmigrant, spawned-out steelhead (kelts). From 1991-1997 a Karluk River steelhead stock assessment project was conducted by the Division of Sport Fish to investigate the potential sources of mortality and to estimate abundance of spawning adult fish. Results from this project indicated that the abundance of the spawning population can be estimated by enumerating and sampling kelts at the weir for sex and size.
Ayakulik River is near the Karluk River and is approximately 90 miles from the city of Kodiak. Little information is available on the dynamics of the steelhead population in this drainage. Kelt counts obtained at an ADF&G salmon weir on the Ayakulik River have generally been lower than those at the Karluk River, but also have been less prone to large fluctuations over years. Abundance of spawning steelhead in the Ayakulik River is unknown. Knowledge of the spawning population of this stock will place it in context with that of the Karluk River steelhead population, and aid in development of effective management strategies for both stocks.
Current objectives of the steelhead research study consist of the following:
- Estimate the number of spawning steelhead in the Karluk River each spring such that the estimate is within 20% of the actual abundance 95% of the time.
- Annually census kelts emigrating through the Karluk and Ayakulik river weirs from late May through mid July.
- Estimate the sex and length composition of steelhead kelts emigrating from the Ayakulik River each spring such that the estimates are within 5 percentage points of the true value 95% of the time.
A weir will be installed annually at the Karluk and Ayakulik rivers during late May. Kelt enumeration and sampling at the weir will occur continuously through mid July. On average five percent of emigrating kelts will be sampled for biological data according to a proportional sampling schedule. Each sampled fish will be measured for length to the nearest millimeter, identified by sex, and, whenever, possible, have scales taken for determining age.