Integrating Genetics, Physiology, and Modeling to Understand the Scale and Mechanisms of Minnow Population Connectivity in a Stochastic Environment

Splittail (Pogonichthys macrolepidotus) are an endemic minnow species of the San Francisco Estuary, currently listed as a California Species of Special Concern. Habitat conservation and management to support stable fish populations requires better understanding of existing populations and their dynamic connectivity across environmental gradients. We have characterized the effective population size and distribution of the two genetically distinct populations and are using these results to gain insight into mechanisms of population connectivity. These populations spawn in divergent habitats and one has a considerably reduced effective population size relative to the other. Our goal is to understand the potential long-term viability of the splittail populations by integrating genetic and physiological results to inform a comprehensive splittail model. This approach provides essential support to understand the complex nexus of ecological and management issues in a human-altered environment.