Finescale dace occurrence and abiotic and biotic covariates for the Belle Fourche River and Niobrara River basins

Aim
The factors that set range limits for animal populations can inform management plans aimed at maintaining regional biodiversity. We examine abiotic and biotic drivers of the distribution of finescale dace (Chrosomus neogaeus) in two Great Plains basins to identify limiting factors for a threatened freshwater fish population at the edge of their range.

Location
Great Plains, Nebraska, South Dakota, and Wyoming, USA

Methods
We investigated abiotic and biotic factors influencing the contemporary distribution of finescale dace in the Belle Fourche and Niobrara River basins with Random Forests classification models using fish surveys from multiple agencies spanning 2008 2019 and GIS-derived environmental data.

Results
In both basins, finescale dace occurrence exhibited a non-linear response to mean August water temperature. Abiotic covariates, including streamflow, water temperature, and channel slope, were important limiting factors in the final model fit with Belle Fourche...