Distribution, Relative Abundance, and Habitat Association of Tallapoosa Bass Micropterus tallapoosae in the Tallapoosa River Drainage, Alabama.

Abstract

The diversity of freshwater fishes and black bass Micropterus spp. in the United States are concentrated in the southeastern region. Dams, anthropogenic land use, fragmentation, invasive species and other factors are contributing to decreasing distributions and increasing imperilment of native fishes in this region. Some black bass, such as the Tallapoosa Bass Micropterus tallapoosae, have recently been elevated to species status but their distribution and imperilment status are unknown. The goal of this study was to determine the distribution of Tallapoosa Bass and examine the land use, habitat, and abiotic variables that contribute to the occurrence and relative abundance of Tallapoosa Bass. Fifty-eight creeks were sampled from May 2019-June 2020 using canoe and backpack electrofishing across six sub-basins. Results indicated that Tallapoosa Bass are well-distributed throughout the Piedmont region, and both average detection and occurrence probability were high. Tallapoosa Bass presence was positively related to the relative abundance of rocky substrate and watersheds that contained a majority percent of hydrologic soil group B (MPSB), which is a measure of runoff potential. Abundance was positively related to rocky substrate, MPSB, the amount of disturbance in the watershed, pool, and gradient; it was negatively related to watershed area. There was good variation in habitat characteristics across the range of Tallapoosa Bass streams sampled during this study. The Little Tallapoosa River Basin above Lake Wedowee seems to have the best assemblage of good streams and habitat characteristics of all the areas examined during this study. Some streams in other areas were also typified by ideal characteristics for Tallapoosa Bass habitat. Streams with small watersheds, high rock scores, and medium to high gradients should be prioritized for protection. Several specific streams across the sub-basin with quality populations based on genetic results, CPUE, and quality habitat characteristics are suggested for protection and conservation. Urban land use impacts, a more extensive temperature study, investigating the effects of flow on movement, migration dynamics, spawning characteristics, influence of shoal and specific rocky substrates, influence of various mesohabitats, interactions with native Alabama Bass, diet, and influence of vegetative cover are suggested as areas of further research for Tallapoosa Bass.