Climate is More Important Than Fishing in Driving Long-term Changes to Estuarine Communities in the Gulf of Mexico

Commercial fishing and climate change have the potential to alter the structure and resilience of marine biotic communities; therefore, it is important to account for the combined impacts of these factors. We used a 38-year (1986–2023) dataset of fishery-independent trawl data collected by Texas Parks and Wildlife Department to assess the impact of a declining commercial shrimp trawl fishery and multiple climate-related variables on the structure of fish and macroinvertebrate communities in Texas inshore waters. Species richness for fishes, arthropods, and mollusks increased despite overall declines in in species diversity. Analyses of taxa sample frequencies indicated that there were substantial differences in community structure between the time periods of 1986–1998 and 1999–2023. Redundancy analysis indicated that changes in community structure were driven by the Atlantic Multidecadal Oscillation (AMO). Our results indicate that most of the community reorganization under the current AMO warm period was due to changes in overall prevalence of a small number of taxa. Although the decline of commercial shrimping has likely had a beneficial impact by reducing mortality among many penaeid shrimp and taxa commonly captured as bycatch, this effect may have been largely overridden by the influence of climatic factors, especially those associated with positive values of the AMO. Our results suggest that the effectiveness of management strategies aimed at increasing the abundance of commercially and recreationally important species may be limited by persistent climate change.