Watershed Scale Analysis of Benthic Macroinvertebrate Food Web Dynamics as Related to Fish Distribution and Abundance in the Upper Yuba River, California

Benthic macroinvertebrate (BMI), fisheries, water quality, and habitat studies were conducted in the Upper Yuba River Watershed, California between 2008 and 2012 in support of two Federal Energy Regulatory Commission (FERC) hydropower relicensing efforts. BMI and physical habitat surveys followed the methods adopted for the California Surface Water Ambient Monitoring Program (SWAMP). Fisheries and water quality data were collected using standard methods and outlined in the FERC-approved study plans.

BMI multi-metric indices such as index of biological integrity and multi-metric index were calculated in order to estimate overall aquatic life use attainment.  These data were used in the development of Protection, Enhancement and Mitigation (PM&E) measures that will be implemented with the approval of each new FERC License.  When BMI data were combined from the two hydropower projects, we were able to relate community metrics and functional feeding group information to resident fish, water quality, and physical habitat data at the watershed scale.  These data allowed us to gain a more detailed understanding of food web dynamics at the watershed scale.  The utilization of standard protocols and best practices in the studies supporting these three hydropower projects resulted in comparable data sets that allowed for this watershed analysis.