Our research

Research areas:

Our lab’s research goals can be summarized as ‘advancing solutions for society’s most pressing issues for fish conservation’ and centers on three main themes: (1) understanding and mitigating threats to small, fragmented populations, (2) ecological and evolutionary impacts following management interventions, & (3) environmental drivers of fish population dynamics.

Understanding and mitigating threats to small, fragmented populations

  1. Using genetic rescue to mitigate extinction risk in imperiled species

Declining populations at the edge of their range are often relegated to small, isolated habitats which can have important demographic and genetic consequences. Genetic rescue has emerged as an important tool to stave off extinction and improve fitness of declining populations. Our previous work has shown that genetic rescue was an effective strategy to improve fitness of an endangered Coho salmon population in the Russian River. However a key finding showed that genetic rescue outcomes depended on environmental context. I am interested in further exploring how to increase resiliency of fish populations in the context of genetic rescue and also evolutionary rescue. More broadly, our lab is interested in the tradeoffs between inbreeding & outbreeding depression and when to mix populations to improve fitness.

Ecological & evolutionary impacts following management interventions

  1. Evaluating success of captive-breeding programs

    Captive-breeding programs are increasingly implemented to curb population declines but can have unintended negative consequences on both genetic and phenotypic diversity due to differing selective pressures between natural and captive environments. Our lab is interested in evaluating the ecological and evolutionary impacts of captive breeding on genetic & phenotypic traits and how to reduce these risks. Our previous research used genetic monitoring and pedigree analyses to evaluate a captive-breeding effort to reintroduce spring-run Chinook salmon into the San Joaquin River in California.

  2. Drivers of reproductive success

I am also interested understanding drivers of reproductive performance and mating systems of captively-bred individuals released into natural habitat. Adult returns of captive-bred fish to the San Joaquin River began in 2017 and ongoing work is quantifying what phenotypic and genetic traits influences reproductive success of these fish in natural habitat.

Environmental drivers of fish population ecology

  1. Quantify the amount of synchrony/asynchrony in population trends over time

    Identifying environmental drivers of demographic variation is critical to predicting population and community level impacts. The degree of synchrony/asynchrony in population trends over time is relevant to conservation applications such as extinction risk. My previous research has found that the timing and magnitude of environmental conditions can be critical in limiting vital rates. We found that higher temperatures can synchronize survival among species within stream fish communities, but that habitat variation can buffer against higher thermal regimes across sites leading to spatial asynchrony in trends over time.     

  2. Effects of environmental extremes on fish population ecology

I am also interested in exploring the impact of a suite of human-induced environmental changes, including shifts away from historical baselines for temperature and precipitation. In the western United States, extreme drought and mega-fires are becoming the norm. I am currently exploring this topic through a collaboration focused on understanding the impacts of the 2014 drought in California on migratory salmonids’ ability to access breeding habitat. Our results show that when drought leads to delayed rains, delayed high flows can result in upstreaming migrating salmonids inability to access upstream spawning habitats resulting in a flow-phenology mismatch.