Author: Brock Peterson, Junior Specialist

As part of an ongoing project funded by the US Army Corps of Engineers (USACE), the lab is evaluating the effect of the current salmonid screening criteria on larval and juvenile green sturgeon. Unscreened water diversions have been identified as a potential cause for sturgeon population declines in the Sacramento-San Joaquin River system; however, the impacts of screened water diversions—which are effective at protecting salmonids under the current criteria—is unknown. 

In our experiments, multiple combinations of sweeping and approach flows were created in the lab’s large “fish treadmill” to replicate the resulting vector flow experienced by fishes as they pass by screened water diversions under current screening criteria. Contacts with the fish screen were recorded in real-time by data collectors, behavioral data—such as passage time and mean distance from the screen—are being analyzed using Noldus Ethovision and Boris software, and acute and latent mortality (48h post trial) were recorded for all trials. Additionally, graduate student Duoli Yang is looking at the non lethal stress impacts of screen interactions. Experiments ran Spring 2023 and 2024.