A physiologically-based oyster larval model, considering differing temperature and salinity regimes

A physiologically-based model, consisting of a system of ordinary differential equations, has been developed to demonstrate the response of oyster larval developmental stages (from trochophore to mature-eyed) to different temperature and salinity regimes. Parameterizations in the model account for temperature and salinity effects on larval growth and mortality. The model is calibrated using temperature, salinity and food concentration values typical of Galveston Bay, Texas, USA. Simulations for Galveston Bay show that extremes in environmental conditions, such as periods of temperatures less than 25 degree C or salinities less than 7.5 ppt, retard larval growth rate. Thus, periods of increased fresh water discharge and/or reduced seasonal temperatures will extend the larval period and increase larval mortality. These types of episodic variations in environmental conditions may result in reduced recruitment to adult oyster populations. Additional simulations, with conditions appropriate for Apalachicola Bay and Chesapeake Bay, show the effect of latitudinal variations in environmental parameters on oyster larval growth and mortality