(Lower Sacramento and San Joaquin rivers, Sutter, Sacramento, Yolo, Solano, Napa, Sonoma, San Joaquin, Calaveras, Stanislaus, and Tuolumne counties)
Species / Location
White Sturgeon (Acipenser transmontanus) is one of two Sturgeon species found in California. This anadromous species is slow-growing, long-lived, and far-ranging—the oldest living and largest freshwater fish in North America reaching lengths up to 20 feet. Because of these life history traits, White Sturgeon are particularly susceptible to changes in environmental conditions brought about by drought; such as reduced water flows, poor water quality, and high water temperatures. Although White Sturgeon have been around for ages, scientists still do not have a complete understanding of their movements and habitat preferences which is critical for making informed management decisions.
Monitoring and Research
This research will evaluate existing data associated with population structure and oscillations of White Sturgeon for the purpose of providing resource managers with science-based options. The objectives are: (1) evaluate and summarize existing data of the population demographics and rate functions; and (2) evaluate likely responses of Sturgeon to changes in harvest management and environmental characteristics (including drought). Results of this work will provide a fundamental understanding of population changes to assist natural resource managers in assessing management alternatives.
Need for Program
On January 17, 2014, Governor Brown issued a proclamation declaring a state of emergency due to prolonged drought conditions. That declaration was then redoubled on April 25, 2014. These Proclamations directed CDFW to take specific actions related to evaluating and managing the changing impacts of drought on threatened and endangered species and species of special concern, as well as to conduct specific monitoring actions described in the State and Federal Water Project Drought Operations Plan. This research directly answers the Governor's call.
Future Efforts
Understanding sturgeon population changes and habitat utilization is important to ensure science-based fisheries management decisions. This project will provide valuable information on modelling approaches, potential proactive management alternatives to protect this valuable public trust resource, as well as habitat assessment techniques. Information gathered by this study will improve our understanding of sturgeon populations and ecology for resource decisions.
White Sturgeon (Acipenser transmontanus) in natural habitat. CDFG photo by Mike Healey.