Association of an endemic leuciscid, the Sandhills Chub, with microhabitat features and watershed‐level habitat characteristics

Abstract

AbstractObjectiveHabitat alteration is the greatest threat to fishes globally, and freshwater fishes are particularly vulnerable to habitat alteration because freshwater ecosystems are more closely integrated with the human landscape than marine ecosystems. Headwater streams comprise the majority of stream length within a watershed and provide unique habitats for a variety of aquatic organisms, thus contributing to drainage wide species diversity by supporting many rare and endemic species. Unfortunately, because of their small size, headwater streams are particularly susceptible to the effects of habitat alteration and conversion of natural land cover to anthropogenically dominated landscapes. Therefore, understanding fish–habitat relationships is essential for conserving and restoring headwater species and their habitats. The Sandhills Chub Semotilus lumbee is a headwater specialist endemic to the Sandhills ecoregion in North Carolina and South Carolina. It has been extirpated from several locations in South Carolina; thus, quantitative information on abiotic habitat factors is needed to guide conservation and restoration efforts. The objective of this study was to produce a predictive model of Sandhills Chub occurrence using microhabitat features and watershed‐level habitat characteristics.MethodsLogistic regression was used to identify which habitat features were associated with the occurrence of Sandhills Chub. Habitat and fish data were collected between 2019 and 2020 at 115 sites within the South Carolina Sandhills.ResultSandhills Chub (total = 431) were collected at 41 out of 115 sites sampled. We observed that Sandhills Chub presence was positively associated with dissolved oxygen levels, instream cover, the percent of substrates between 6 and 11 mm, and elevation and was negatively related to the number of impoundments within each 12‐digit hydrologic unit code.ConclusionThe Sandhills Chub prefers streams that have high dissolved oxygen content, presence of instream cover, the substrates necessary to construct their pit‐ridge nests, low numbers of impoundments on the streams, and higher elevations within the Sandhills. Results from this study will provide important information to guide management decisions for the future conservation and restoration of Sandhills Chub.