PROJECT HIGHLIGHT:
This project will use citizen science to study and quantify non-fishing deaths of sturgeon in the San Francisco Bay-Delta Estuary, with a particular focus on ship strikes in the Carquinez Strait. Through a combination of public reporting, mark-recapture studies and analysis of sturgeon carcasses, the research aims to better understand the scope of sturgeon mortality beyond recreational fishing, which is crucial information for protecting these threatened species.
PROJECT SUMMARY:
The San Francisco Bay-Delta Estuary is home to both white sturgeon and federally threatened green sturgeon, but these ancient fish face growing challenges to their survival. While some recreational fishing impacts on white sturgeon survival are known, there is limited understanding of other sources of sturgeon deaths, particularly from ship strikes in the busy shipping channels of the Carquinez Strait. A recent pilot study documented 95 sturgeon carcasses in this area over just four years, suggesting this could be a significant but under-recognized threat to these vulnerable fish populations.
This project will develop a comprehensive system to document and analyze sturgeon mortality in the Carquinez Strait region. The researchers will create a citizen science network for reporting sturgeon carcasses, combining public observations with systematic scientific surveys. They will conduct mark-recapture studies of sturgeon carcasses to estimate what percentage of deaths go undetected, and analyze the age and migration patterns of the fish using their fin rays. This information will help reveal which life stages and migration patterns make sturgeon most vulnerable to ship strikes.
By engaging both the public and the scientific community, this research will provide crucial data about non-fishing mortality in sturgeon populations — information that is currently missing from population models and management plans. The project will also investigate public perceptions about sturgeon conservation through community workshops and surveys. The findings will support more accurate population assessments and help guide management strategies to protect these iconic California fish, particularly as white sturgeon are currently being considered for listing under the California Endangered Species Act.
Associated Project Personnel:
Nicholas Demetras (University of California, Santa Cruz)
This project is funded by the Delta Stewardship Council Delta Science Program under Agreement No. DSC23000, and is administered by California Sea Grant.
Benjamin Burford