Final Report: Data compilation, distribution models, conservation planning, and status survey for selected fishes of concern in Texas and region


The four primary objectives of this project were to: (1) compile a dataset of georeferenced range-wide occurrence records for 6 target fish species (Notropis buccula, N. oxyrhynchus, N. girardi, Hybognathus amarus, Platygobio gracilis, Macrhybopsis tetranema, Pteronotropis hubbsi, and Percina maculata); (2) use a high quality and geographically wide-ranging subset of those data to create species distribution models (SDM’s), which convert point occurrences into a continuous probability coverage; (3) use those models in conjunction with 130 additional SDM’s (previously created) to develop modeled conservation priority areas for Texas; and (4) complete a status survey for N. oxyrhynchus and N. buccula in the mainstem of the middle Brazos River. The dataset provided, derived from 51 original sources, includes 11,082 records, of which we were able to georeference 3,675 (33%). This number of records was sufficient for constructing SDM’s for the six target species, with all models meeting quality assurance criteria. Using these models, conservation area prioritizations were developed for Texas under several guiding criteria for decision making. The field survey sampled the mainstem Brazos at 20 sites between Possum Kingdom Reservoir and Bryan, TX, collecting 65,840 fish specimens representing 46 species. Neither survey target species was collected, suggesting absence or extreme rarity of both in this reach of the Brazos at the time of sampling. Collection sites upstream of Waco, compared to those downstream of that city, were less diverse in cyprinids and more diverse in non-native species, suggesting more heavily impacted habitat upstream of Waco. All raw data used in analyses and results of analyses and the field survey are provided with the written report.