Freshwater Inflow Recommendation for the Trinity-San Jacinto Estuary Based on Analysis of Long-Term Fisheries Survey Data

The Texas Water Development Board (TWDB) and Texas Parks and Wildlife Department (TPWD) have developed methodology for determining the freshwater inflow (FWI) needs of Texas estuaries based on computer optimization and hydrodynamic modeling. This approach has focused on relating historical commercial fisheries harvest to bay salinity conditions as the main effect of freshwater inflows. However these model results are predicted solutions, and it is important to independently verify whether results are realistic for maintaining estuarine productivity. In order to validate the effect of inflows on fish and shellfish target species and their critical estuarine habitat, TPWD has designed additional analyses which correlate species' distributions and critical habitat requirements with historical salinity regimes occurring in the estuary. The results of this analysis are presented for the Trinity-San Jacinto Estuary using TPWD Coastal Fisheries trawl sampling data collected over a 12 year period.