Establishment and proliferation of nonnative fish species hinders the recovery of endangered species listed under the U.S. Endangered species act

The U.S. Fish and Wildlife Service awarded a $136,318 Cooperative Agreement under the Endangered Species Recovery Implementation program (CFDA 15.657) to The Ohio State University. The project will develop a population model using statistical catch-at-age analysis to estimate age-specific abundance, mortality, and recruitment dynamics of nonnative channel catfish in the San Juan River basin. This model will assess how annual recruitment is impacted by spawner biomass and environmental variation, and could be extended to incorporate spatial dynamics, genetic manipulations, and simulate population responses to future management actions. The goal is to provide data and analysis to support federal recovery programs that use mechanical removal of nonnative fish to aid the recovery of endangered native species in the Colorado River basin. The project period runs from March 1, 2024 to February 28, 2026.

In response, federal recovery programs in the colorado river basin implement mechanical removal efforts to reduce the abundance of nonnative fish that prey upon native species. The SAN juan river basin recovery implementation program has been removing nonnative fish since the late 1990S. This project will use data collected by the recovery program on nonnative channel catfish abundance and size structure to develop a population model. Our objective is to develop a population model using a statistical catch-at-age framework to estimate age-specific abundance, natural and fishing mortality, and recruitment dynamics of channel catfish in the SAN juan river. This model will allow US to assess how annual recruitment is impacted by spawner biomass and environmental variation. In later years of the project, the model could be extended to incorporate spatial dynamics, genetic manipulations, and to simulate the population response to potential future management actions to aid recovery of endangered fish species.