Takotna river salmon run timingand abundance

This project focuses on providing reliable escapement estimates for chinook salmon oncorhynchus tshawytscha and chum salmon o. Keta in the takotna river. Management of kuskokwim area salmon fisheries is complex because of variability in run size, timing, and harvest of mixed stocks, overlapping runs of multiple species, allocation issues, and the immense size of the kuskokwim river drainage. Chinook salmon of the kuskokwim river watershed spawn in over 25 distinct areas, with each spawning subpopulation likely adapted to local, sub-watershed, conditions through traits such as juvenile behavior and residence time, and adult spawning duration and timing. These adaptations result in different productive capacities (i.e., average number of adult recruits expected per spawner), different carrying capacities (i.e., maximum number of spawners or juveniles a freshwater habitat can support), and different responses or tolerances to fishing pressure and environmental change. This variability in productivity and adaptation is critical to supporting resilience to environmental change and to dampening variability in fishery harvests. This diversity, or portfolio, of subpopulations with different characteristics allows some stock components to flourish when other components have responded negatively to environmental conditions or harvest pressures. Specific issues important to federal management in support of subsistence fisheries include: maintaining salmon diversity biocomplexity is critically important for federal subsistence management. IT is important to maintain the full complement of salmon diversity, including those stocks which are currently less productive or small in size that migrate through federal waters and help support subsistence needs. Weir-based stock assessments typically focus on more abundant or more productive chinook populations. This focus can introduce bias in the spawner recruit analysis in an anti-precautionary direction, providing a more optimistic perception of watershed productivity than is warranted. The takotna river weir is the only project in the watershed that monitors the dynamics of small populations of salmon species, and therefore functions as a sentinel with a long-term time series for dozens of discrete smaller, less productive populations in the kuskokwim region. Based on these considerations, this project has disproportional benefits and addresses diversity mandates within the yukon delta national wildlife refuge. In conjunction with salmon escapement data, there is a need to assess and evaluate the impacts of climate change on the kuskokwim river ecosystem. Assessment of climate change impacts depends on long-term environmental data to provide a meaningful timeframe for comparison. The overarching project goal is to continue a long-term, ground-based project that will adequately index escapement to the headwaters of the kuskokwim river, continuing the only long-term data set evaluating chinook and chum salmon escapement to a headwater tributary, while also continuing the time series of environmental data to provide researchers and managers with indices useful to understanding local impacts of climate change. Specific project objectives include: 1. Enumerate the daily passage and characterize the run timing of chinook salmon through a resistance board weir. 2. Enumerate the daily passage and characterize the run timing of chum salmon, and resident fish species through a resistance board weir. 3. Estimate the weekly age, SEX, and length composition of chinook salmon. 4. Collect seasonal passage information of other fish species.