The primary goal of the Comprehensive Everglades Restoration Project is to restore more natural freshwater flow through the south Florida ecosystem including quantity and timing of freshwater deliveries into the system, and maintaining water quality within the overall system. Understanding the effect of salinity and temperature, beyond typical oscillations, on the biota of the South Florida estuaries is necessary for the successful outcome of the overall goals of CERP. These experiments addressed two aspects of the Ecosystem History Projects: 1) determining the utility of using molluscan shells as recorders of change in water chemistry parameters, primarily salinity, and 2) enhancing our in situ observations on modern assemblages by exceeding typically observed conditions. These experiments allowed us to gain an understanding of the effects of salinity, temperature and other water chemistry parameters on the reproduction, growth and overall survivability of key species of mollusks, used in interpreting sediment core data.

Observations on mollusks, plants and microbes made as part of these experiments have further refined our knowledge and understanding of the effects of ecosystem feedback and what role salinity and temperature play in ecosystem stability. Data collected on the effects of salinity and temperature driven changes need to be verified or tested in the field. The mesocosms and experiments were designed in part based on observations made in South Florida estuaries. Observations made in the mesocosms, on a scale not normally observable in the field, have led to new questions about the influence of salinity on the localized ecosystem, which need to be tested in situ.

The results have demonstrated the viability of several molluscan species (for example Cerithium muscarum, and Bulla striata due to the ability to withstand a broad salinity range) that could be utilized as indicators of atypical salinity, and possibly temperature, oscillations. These data and the use of these species can provide a more accurate measure of anthropogenic influence in the South Florida estuaries. The experiments also have provided calibration data for the shell biogeochemistry of Chione cancellata and the use of this species as a water chemistry recorder. The next phase of experiments will test the stress levels/survival rates of repeated, short duration changes of salinity and temperature at various intensities. We would also like to expand the biogeochemistry study of Chione cancellata to include several of the gastropod species utilized in this experiment.