Environmental and Water Quality Operational Studies. Fish and Invertebrates of Revetments and Other Habitats in the Willamette River, Oregon.

In this study, physical and biological parameters were compared at revetments and other aquatic habitats in the Willamette River below Salem, Oregon. The purpose was to determine if revetments affect the distribution and abundance of fishes and invertebrates, and to examine relationships between the physical parameters and the biological community. Sampling sites included two revetments, two natural banks, two side channels, and an abandoned channel. The study was conducted in 1982 at two flow levels. Sampling periods were June when flows were moderate 283-425 cu msec and August when flows were low 221-238 cu msec. The physical parameters included water quality indices temperature, dissolved oxygen, pH, redox potential, turbidity, and conductivity, water velocity, and sediment analysis. The biological parameters were fish and invertebrate densities and fish weight. During each study period, water quality indices were similar at all stations except for those in the abandoned channel, which was generally higher in water temperatures and conductivities and more variable in dissolved oxygen. Water temperatures and turbidities were higher during the August sampling period compared to June. Water current velocities were highest at the natural bank sites followed by the revetments and secondary channels. The abandoned channel had little or no water flowing through it.