Benchmarking community structure of estuarine-dependent nekton near the Aransas Pass inlet
The purpose of this study is to determine the baseline seasonal community structure of estuarine-dependent nekton (fish, shrimp, and crab) in the Aransas Pass inlet region to establish a pre-operational benchmark prior to newly proposed industrial development in this area. Many nekton occurring in coastal waters share a common estuarine-dependent life history strategy characterized by near-shore spawning in the Gulf of Mexico with larvae migrating through tidal inlets into shallow estuarine nursery habitats. Access to high-quality habitat and spawning grounds via tidal inlets is essential for the reproduction, growth, survival, and maintenance of these populations. Because 75% of commercially or recreationally important species in the Gulf are estuarine-dependent, evaluating how anthropogenic activities may impair this connection between Gulf and bay waters is critical to understanding the population dynamics in this system and how these factors may affect juvenile fish development and fishery productivity. The Aransas Pass inlet is the major tidal inlet for the region, and anthropogenic activities that may alter water chemistry, flow, and quality have the potential for significant negative impacts on the marine life using this migration corridor. The proposed industrial development of the Aransas Pass inlet region (e.g., Harbor Island) presents a critical opportunity to establish baseline community structure in the adjacent estuarine habitats. We found strong evidence that the Aransas Pass, where impacts from industrial development are likely to occur, and Packery Channel (located ~35 km south), where these impacts will likely be absent, inlets have wide-ranging differences in nekton recruitment and development at individual species and community levels. Based on the findings of this study, we recommend continued long-term monitoring in the Aransas Pass and Packery Channel inlet regions to establish baseline variability and appropriately capture planned and unplanned future natural and anthropogenic disturbances and scenarios of environmental change. Baseline studies such as this facilitate effective management plans to preserve the function of these inlet regions as nurseries and fulfill the CBBEP mission to protect and restore the health and productivity of Coastal Bend bays and estuaries while supporting continued economic growth and public use of the bays.