Spatial-Temporal Distributions of Dominant Estuarine Species Along the Texas Coast

To facilitate improved management and conservation of critical estuarine ecosystems, it is imperative to understand the communities that comprise them, as well as the ecological factors that mediate their dynamics. Fisheries-independent trawl surveys conducted in Texas estuaries from 1986-2007 were used to examine species compositions across a large spatial and temporal scale. Despite large variability in environmental conditions, it was found that five species dominated community composition along the 600 km coastline: Atlantic Croaker (Micropogonias undulatus), Spot (Leiostomus xanthurus), Bay Anchovy (Anchoa mitchilli), Blue Crab (Callinectes sapidus), and White Shrimp (Litopenaeus setiferus). Using a hierarchical generalized additive model, we explored variation in historical distributions and abundances of these key species in relation to a suite of geomorphic and abiotic factors. Species-specific models were developed for each major estuary (n=8) and for the system as a whole. Predictor variables differed between models, however factors such as temperature, salinity, depth, and habitat type were commonly retained. The methods and results of this study will allow resource managers to prioritize conservation areas by assessing community dynamics under simulated future ecological disturbances and climate change.