Behavioral Response of Juvenile Chinook Salmon, Oncorhynchus tshawytscha, To Trash Rack Bar Spacing
bar spacing, behavioral barriers, behavioral responses, California, channel, chinook, juvenile, light intensities, Oncorhynchus tshawytscha, predation, salmon, spacing, trash racks, vertical bars, water velocity
Journal or Book Title
California Fish and Game
The behavioral response of juvenile chinook salmon, Oncorhynchus tshawytscha, to vertical trash racks having interbar spacings ranging from 5.1 to 30.5 cm is reported. Experiments were conducted in a laboratory channel with an average water velocity of 32 cm/sec under light intensities of 14.0 and 1.0 x 10^-2 footcandles. Transit times were not significantly different between light levels, but differences between bar spacings were significant. Observed changes in rheotaxic posture and hesitancy to pass through a trash rack with bar spacing less than 15 cm would increase the susceptibility of juvenile fish to predation. Abstract courtesy of California Fish and Game.