Monday May 18, 2026
Sierra Sun Times —
Tucked within the UC Davis campus, a quiet but critically important effort is helping preserve the Longfin Smelt, a vulnerable fish species native to the Sacramento–San Joaquin Delta. Scientists with DWR and UC Davis are collaborating to better understand and conserve this declining species through immediate conservation actions and long-term research.
Longfin Smelt are an indicator of estuarine health. “They can be thought of as the canary in the coal mine,” said Brian Schreier, an environmental program manager with DWR, noting their decline reflects broader ecosystem stress. Federally listed as endangered, these fish can live as long as three years. They migrate to the Pacific Ocean during their first year, then return to the San Francisco Bay Estuary and its tributaries to spawn in their second or third year.
Protecting Longfin Smelt means addressing multiple threats. A major concern is entrainment, where fish are drawn into water export facilities. DWR focuses on minimizing these impacts while managing water flows to support spawning and survival. Water quality, contaminants, limited food supply, and predation all threaten the survival of the species.