Development of an Experimental Plan for Delta Smelt Population Reinforcement

Delta Smelt

For more information contact Daphne Gille:

Background and Significance of Study

The Delta Smelt is a state and federally listed species that is facing extinction throughout its native range in the San Francisco Estuary. Given the tenuous status and rarity of wild Delta Smelt, we must consider that recovery may not be possible without population reinforcement using refugial hatchery fish reared at the UC Davis Fish Conservation & Culture Laboratory (FCCL). However, before population reinforcement can occur, experiments are needed to fill critical knowledge gaps about the species.

In a two day workshop in May 2017, funded by the California Department of Water Resources and organized by Cramer Fish Sciences, agency managers, university scientists, technical experts, and stakeholders from across the nation met to discuss the future of this imperiled species and what experimental questions must be answered to inform possible future population reinforcement. Important next steps to be addressed that were identified by the workshop participants included:

  • Create a structure-based decision model to aid agency scientists in Delta Smelt recovery decisions.
  • Develop a Delta Smelt genetic management plan specific to population supplementation or reintroduction.
  • Expand pathogen screening of cultured Delta Smelt.
  • Optimize physical and genetic tags that can distinguish wild from hatchery-reared Delta smelt.
  • Test if Delta Smelt reared in the hatchery can survive under environmental conditions that occur in the San Francisco estuary (natural food resources, turbidity, salinity, temperature, etc.).
  • Devise an outreach strategy to engage the public in Delta Smelt conservation and recovery.

The GVL is part of a multi-agency team that is currently crafting an experimental work plan and will perform pilot studies to fill the above critical knowledge gaps as we prepare for Delta Smelt population reinforcement. Stay tuned for updates on our progress!

The GVL was well-represented at the Delta Smelt reinforcement workshop!

(Photo credit: Lindberg) The delta smelt hatchery at FCCL.



Ted Sommer and Brian Schreier (California Department of Water Resources)

Richard Connon, Nann Fangue, Jim Hobbs, and Tien-Chieh Hung (UC Davis)

Evan Carson and Bob Clarke (US Fish and Wildlife Service)

Mark Clifford (California Department of Fish and Wildlife)

Andrew Schultz and O. Town Burgess (United States Bureau of Reclamation)

Bruce DiGennaro (Essex Partnership)

Brad Cavallo and JoAnna Lessard (Cramer Fish Sciences)