Spatiotemporal and Environmental Effects on Demersal Fishes Along the Nearshore Texas Continental Shelf

The goal of this study was to analyze data from a 10-year bottom longline survey to examine spatial, temporal, and environmental effects on demersal fishes along the Texas coast within the northwestern Gulf of Mexico. Generalized additive models (GAMs) and generalized linear models (GLMs) were employed to evaluate trends and patterns in species composition (species richness and species diversity), relative abundance, and presence probability of fish species in the Texas region of the northwestern Gulf of Mexico. Temperature, salinity, and dissolved oxygen were the most influential variables driving richness, diversity, and abundance of demersal fish assemblages. The community was dominated by six species that represent 93% of total catch: Rhizoprionodon terraenovae (Atlantic sharpnose shark), Bagre marinus (gafftopsail catfish), Sciaenops ocellatus (red drum), Carcharhinus limbatus (blacktip shark), Carcharhinus brevipinna (spinner shark), and Carcharhinus leucas (bull shark). Analyses of dominant species revealed that multiple factors modulated their presence probability, with temperature and dissolved oxygen as common environmental drivers among species. Findings from the present study suggest that the composition and abundance of demersal fish assemblages were shaped by key environmental drivers.