Upstream Migration Timing of Columbia Basin Chinook and Sockeye Salmon and Steelhead in 2015
In 2015, we sampled Sockeye and Chinook salmon as well as steelhead at the Bonneville Dam Adult Fish Facility (AFF). Fish were measured for length, scales were collected for analysis of age, and the fish were tagged with Passive Integrated Transponder (PIT) tags. These fish were tracked upstream as they passed through sites with PIT tag antennas, including fish ladders at dams, juvenile bypasses, hatcheries, weirs, as well as in-stream antennas. Total numbers of fish tracked upstream were 1294 spring Chinook, 616 summer Chinook, 1653 fall Chinook, 901 Sockeye salmon, and 898 steelhead. High temperatures adversely affected sampling in 2015, completely shutting down the AFF for three weeks plus parts of seven additional weeks. Between weeks 26 and 29, sampling restrictions resulted in only 93 summer Chinook sampled in a period when 67.4% of the run passed. No sampling during Week 33 meant we were unable to sample the peak week of steelhead passage when 14.5% of the run passed. For Sockeye, 22.2% of the run passed between July 2 and 23 when we were not able to sample due to restrictions. High water temperatures meant our sampling was less representative of the run at large than in past years, resulting in some changes in data analysis and cautions in interpreting results.
Fryer, J.K., J. Whiteaker, and D. Kelsey. 2017. Upstream migration timing of Columbia Basin Chinook and Sockeye Salmon and steelhead in 2015. Columbia River Inter-Tribal Fish Commission Technical Report 17-07 for U.S. Dept. of Energy Bonneville Power Administration Project 2008-518-00. 121p.