Green sturgeon movements in the lower Sacramento River, water years 2021-2025

The U.S. Army Corps of Engineers American River Watershed Common Features project (ARCF) seeks to reduce flood risk for the City of Sacramento, California, and surrounding areas and improve fish access to additional habitat. The project includes levee-remediation measures to address seepage, stability, erosion, and height concerns as well as the widening of the Sacramento Weir and Bypass. The project reach is in the lower extent of the Sacramento River migration corridor for the federally threatened southern Distinct Population Segment of North American green sturgeon (Acipenser medirostris). To establish baseline migratory behavior, we examined adult green sturgeon transit through the project area prior to and during the in-water construction period. Biologists from the U.S. Army Corps of Engineers collected and tagged 121 adult green sturgeon with acoustic transmitters and passive integrated transponders, near Hamilton City, California, at river kilometer 332 of the Sacramento River each fall from 2020 to 2025. To evaluate fish movements, we deployed eight acoustic detection sites at river kilometers 127, 103, 101, 90, 76, and 21 on the Sacramento River, in Tule Canal near the Sacramento Bypass, and in the American River near the confluence of the Sacramento River. No fish were detected in Tule Canal nor the American River. Telemetry data were collected on the 69 kHz acoustic frequency.