Seasonal and spatial variations between the fish community and environmental factors in a subtropical estuary

Abstract

Galveston Bay is a subtropical estuary on the upper Texas coast along the northwestern region of the Gulf of Mexico (USA). This study presents results of a meta-analysis on fisheries independent abundance and environmental data collected from 1993 to 2016 (3469 sampling events). In total, 404,160 individual fish were collected using bag seines comprising 122 species from 91 genera, 53 families and 22 orders. Diversity measures reveal the number of individuals, species richness and the Shannon diversity index exhibit a seasonal cycle (decrease in winter, increase in summer). Fish populations also exhibited spatial variability which was largely attributed to the varying stages of their life cycles. Community metrics varied temporally and were not adversely influenced by periods of drought, flood, or other extreme events. Galveston Bay appears to be providing a sound ecological environment, and not yet exhibiting climate change influences on the fishery, as has been reported for other estuaries.