The impacts of hydrology on the life cycle of California white sturgeon

Anthropogenic alterations, such as water diversions for human consumption, have degraded habitat quality for aquatic ecosystems worldwide. One of these heavily modified habitats is the San Francisco Estuary, home to a distinct population of white sturgeon ( Acipenser transmontanus). This population has been in decline, driven by intermittent recruitment and mortality by factors such as overharvesting and harmful algal blooms, and is being considered for listing under the California Endangered Species Act. Little is known about the early stages of white sturgeon life cycle and how hydrological alterations affect them. In this paper, we use general linear mixed models to identify relations between the hydrology in the San Francisco Estuary and aspects of the white sturgeon life cycle that affect white sturgeon early stages. We find that the visitation of spawning sites and the probability of catching young-of-year white sturgeons are significantly correlated with increased Delta outflow, i.e., an increase in water flowing out of the Estuary. This information will be critical to inform management strategies that promote the persistence of white sturgeon in California.