Nearshore Salinity and Juvenile Pink Shrimp (Farfantepenaeus duorarum): Integrating Field Observations, Laboratory Trials, and Habitat Suitability Simulations

The pink shrimp Farfantepenaeus duorarum is one ecological indicator of the Biscayne Bay Coastal Wetlands (BBCW) project, which intends to increase mesohaline and oligohaline areal extent along southwestern Biscayne Bay nearshore areas. These changes were anticipated to benefit pink shrimp abundances. My dissertation tested whether increased mesohaline and oligohaline area within a 50-m strip of shallow-water shoreline area likely would increase pink shrimp densities. First, I carried out a comprehensive literature review that revealed polyhaline and/or euhaline salinity regimes generally maximized pink shrimp occurrence, abundance, growth, and survival. Next, I analyzed 10 yrs of pink shrimp density and habitat observations which revealed spatial density patterns with reduced density in areas marked by low mean salinity and higher salinity variation. Third, laboratory study investigating salinity effects (5, 10, 15, 25, 35, 45, and 55 ppt) on pink shrimp molt increment and intermolt period did not reveal significant relationships although parabolic salinity responses for linear growth in weight and length where observed (maximal growth at 34 and 33 ppt, respectively). Lastly, I simulated salinity effects on pink shrimp habitat under Base Flow and High Flow (~2x Base Flow freshwater discharges) restoration scenarios. Under Base Flow, the areal extent of wet season “good” and “optimal” habitat suitability totaled 91.5% of the simulated domain; under the High Flow scenario this was reduced to 74.3%. This dissertation revealed that reduction of nearshore salinities to oligohaline (0-5 ppt) and mesohaline (5-18 ppt) regimes would negatively impact pink shrimp density, growth, survival, and habitat suitability