Poster Presentation Society for Freshwater Science 2026 Annual Meeting

Benthic Macroinvertebrates and Juvenile Winter Run Chinook Salmon in Sacramento River Side Channels: Indicators of Juvenile Salmonid Habitat Quality (134750)

Parsa Saffarinia 1 , Jordan Kruger 1
  1. Biology, California State University Chico, Chico, CA, United States

The Sacramento River has had a series of restoration projects in recent years poised at restoring habitat for salmon spawning and juvenile rearing. This project focuses on one of those restoration sites, the Kapusta island complex. This complex is a series of interconnected human made and naturally carved channels in the Sacramento River, restored for the purpose of Winter Run Chinook salmon conservation. However, scant information exists on the quality of these sites, namely that of benthic macroinvertebrates. Thus, we compared community structures of restored channels versus non-restored channels on the island and outlined methods for improving habitat. Samples were collected following a modified Surface Water Ambient Monitoring Program (SWAMP) protocol accounting for micro-habitat. 600 benthic macroinvertebrates were subsampled from samples and taken to their farthest suitable epithet, usually genus or species. Preliminary data suggests higher abundances of Glossomatidae and Chironomidae in restored channels. Non-restored channels contain higher counts of oligochaetes and gastropods. Plecoptera have been infrequent in either channel with one Claassenia sabulosa found in the restored channel. We project restored channels to hold a starkly different environment from non-restored channels. While either channel type presents habitat for juvenile salmonids, restored channels provide a higher quality habitat. Neither channel presents suitable communities for juvenile salmonids. Changes to test in future studies may include higher diversification of substrates, increased introduction of wood debris, and increased channel restriction points to improve dissolved oxygen levels.