Field Investigations of Florida Bay Water Quality  
Several cruises have been completed in 1997 to survey the water quality in Florida Bay. During these cruises, our group has measured carbonate system parameters (including total alkalinity (TA), pH, total carbon dioxide (TCO2), and partial pressure of carbon dioxide (pCO2), as well as salinity and nutrients. In addition, our group has measured samples collected by other groups. TA, pH, TCO₂, and pCO₂ have been used in an effort to characterize the carbonate system in Florida Bay. The carbonate system data collected have been used to evaluate the saturation state of calcite and aragonite particles that can absorb phosphate, as well as to examine the uptake of inorganic carbon by phytoplankton. A flowing multi-parameter nutrient system, developed in our lab, has been used on several of the cruises to continuously monitor nutrient concentrations. Nutrient data (nitrate, nitrite, phosphate, and silicate) have also been combined with the carbonate parameters to examine the relationship between the carbonate system and nutrient elements in Florida Bay water. Chlorophyll-a data were also collected during a cruise to evaluate primary production of Florida Bay water. The results of the carbonate, nutrient, and chlorophyll-a data are summarized in Table 1. The lower values were found offshore and along the coastal line of Key West, the higher values were found in Shark River. Fig.1a(NO2),1b(NO3),1c(PO4) and 1d(SiO2) shows the results of nutrient concentrations for our November 1997 cruise onboard the R/V Calanus. Fig. 2 shows the nutrients and carbonate parameters in the Shark River. Fig. 3a and 3b shows the carbonate parameter measurements made in Shark River. The alkalinity increases from 2300 mM outside of the river to 7000 mM while the pCO2 increases from around 600 ppm to 2700 ppm. The high CO2 measurements are related to the biological and perhaps photochemical degradation of plant materials in the river. We plan to continue to participate on cruises in Florida Bay over the next year with others working in the program.