Factors from Multiple Scales Influence the Distribution and Abundance of an Imperiled Fish – Mountain Sucker in the Black Hills of South Dakota, USA
An understanding of the factors associated with the distribution of fishes is fundamental to stream ecology, and can be used to assess and prioritize conservation areas. Mountain sucker Catostomus platyrhynchus is generally stable across its range in Western North America, but recent studies have documented declines at finer spatial scales near the periphery of its range, including the Black Hills of South Dakota. Despite its wide-ranging distribution, little information exists on mountain sucker autecology or community dynamics.
The objective of this study was to evaluate the hierarchical influence of physical and biological variables on the distribution and abundance of mountain sucker in streams of the Black Hills, South Dakota, USA. We evaluated the support for candidate models that incorporated multiple spatial scales and potential biotic interactions to model mountain sucker presence and abundance using an information theoretic approach. Mountain sucker presence was best explained by a combination of reach-scale habitat and fish assemblage variables, including a negative influence of trout abundance. Mountain sucker abundance increased with periphyton coverage, a food resource.
These models increase understanding of mountain sucker ecology, can be used to assess and prioritize areas of conservation interest for this native fish in the Black Hills, and can identify management actions that will provide the most effective conservation strategies for this species.