The Effects of a Native Fish Reintroduction on Resident Fish Assemblages

Abstract

Native fish reintroduction can be a valuable conservation tool used to curb declines in biodiversity. Previous native fish reintroduction projects have focused on monitoring population responses of the target species, yet potential changes in the resident fish assemblages have received less attention. The reintroduction of the Bluebreast Darter (Etheostoma camurum) to the Upper Licking River basin in Ohio was used as a model to understand how reintroduction may alter resident fish assemblages. This reintroduction began in 2016, with one additional year of stocking in 2017, and yearly follow-up surveys through 2019. Fish community, water-chemistry, and fluvial geomorphic measurements were also performed at the reintroduction sites. I found that the benthic fish assemblage diversity and evenness increased over time in response to the reintroduction, with coarser substrate emerging as an important mechanism of reintroduction success. Both diversity and evenness increased post reintroduction, peaking in 2018 and then dropping back down to similar levels at the beginning of the project. This research helps to better understand how reintroductions may impact aquatic assemblage architecture and inform future reintroduction efforts.