The Feather River is the largest tributary of the Sacramento River in northern California, and the north, middle, and south forks of the river meet at Lake Oroville. FISHBIO and our project partners from Spring Rivers Ecological Sciences conducted compliance monitoring on the North Fork Feather River on behalf of PG&E in 2021. Fieldwork included electrofishing and snorkel surveys of the fish community as well as monitoring of benthic macroinvertebrates. Results of this monitoring effort will help establish baseline (first year) conditions for future comparison and evaluation of the fish population’s response to the river flow regime under federal licensing requirements.
At three monitoring locations along the river, block nets were erected and depletion electrofishing was conducted through multiple passes of the project reaches using backpack electrofishers. Captured fish were processed to collect length and weight measurements, which were subsequently used to estimate weight-length relationships and condition factors, evaluate length and age structure of species encountered, and to calculate fish density and biomass estimates for each location. In areas that were too deep for effective electrofishing, snorkeling was used to conduct visual observation surveys in order to calculate indices of abundance and density, as well as community composition. Benthic macroinvertebrate collection and habitat assessments were also conducted at each monitoring location.