Summary Of Catch And Biological Data Collected During Juvenile Salmonid Monitoring On The Mainstem Klamath River Below Iron Gate Dam, California, 2017

This report summarizes results from the 2017 season of juvenile salmonid outmigrant monitoring on the mainstem Klamath River below Iron Gate Dam. Trapping occurred at three locations: below the confluence with Bogus Creek (river km 308), near where Interstate 5 crosses the Klamath River (river km 294), and near the Kinsman Creek confluence upstream of the confluence with the Scott River (river km 238). High and variable river flows throughout much of the trapping season prevented the continual operation of traps, contributed to flawed sets at all three trap sites that precluded estimates of abundance, and likely contributed to the overall low catches observed relative to other years. Both frame nets and rotary screw traps were used to sample juvenile salmonids and other fishes. Traps were deployed in late February (Bogus trap site), early March (I-5 trap site), and early June (Kinsman trap site) and were operated until late May (Bogus and I-5 trap sites), or late June (Kinsman trap site). Juvenile salmonids were enumerated daily when traps were operating and subsamples of salmonids were measured for length, weight, and external symptoms of disease. Non-salmonid fishes were also enumerated and subsampled for length measurements. Natural-origin age-0 Chinook Salmon were captured at each of the three trap sites in all weeks that sampling occurred and displayed few external symptoms of disease. Natural-origin juvenile Coho Salmon and steelhead were also observed in relatively low numbers at all three sites during the trapping season.