Relationship Between Spring Flow and Fish Communities of the Edwards Plateau

Origins of endemic fishes within the Edwards Plateau region of Central Texas are associated with spring habitats emanating from karst-terrain aquifers. Current and future persistence of endemic fishes also are linked to spring habitats but the relationship is based on observational data.  Objectives of this study were to quantify spring fish richness, relatively abundances, and densities along a longitudinal gradient from spring outflows to river reaches among six spring-river complexes and to assess the relationship between spring base flow magnitude and spring fish occurrences.  Results suggest that spring fishes have affinities for spring systems but not exclusively.  In addition, spring fish richness, relative abundances, and densities were positively related to spring flow but not all relationships were linear.  Findings of this study are beneficial for understanding possible evolutionary mechanisms underlying spring fish associations for spring habitats and by providing a model to estimate spring flows necessary to maintain spring fish communities.