Icthyoplanktonic vertical distribution & ingress in the Aransas Pass inlet system

In the Coastal Bend region of Texas desalination plants have been proposed as a solution to water usage problems. These plants take in brackish/marine water and dispose of brine, which in coastal inlets would create a plume of water with higher salinity and temperature. Desalination plants could impact estuarine dependent fishes whose larvae pass through the inlets on their way to nursery habitat. In this study I sample the Aransas Pass Inlet system, in the vicinity of one of the proposed desalination plans, during day and night and during both incoming and outgoing tides at three different depth strata, to provide data on larval assemblages in the channel. Results showed that larval were greatest in the deepest stratum and during nighttime hours. Key spawning months for several important families were also confirmed. Briny discharge may adversely affect larval development and survival depending on sensitivity to abrupt changes in salinity and temperature, which differs by species and developmental stage. Currently there are no specific regulations addressing desalination plant discharge, but this research suggests those regulations should limit the location and timing of discharge to mitigate potential negative impacts on local ichthyofauna.