Carbonate chemistry of the Florida reef tract

Coral cover in the Florida Keys has been surveyed extensively in the past few decades as multiple stressors have contributed to reef decline throughout the Caribbean. The current study represents the first survey of carbonate chemistry of the Florida reef tract. The distributions of pH, pCO2 and aragonite saturation state will be determined from measurements of total alkalinity (TA), and dissolved inorganic carbon (DIC) from eight onshore-offshore transects stretching from Key West to Key Largo and from continuous measurements of pCO2 taken while underway. Using the alkalinity-anomaly method and a SOMMA (single operator multiparameter metabolic analyzer) with automated coulometer provided measurements of the drawdown of TA and DIC, respectively. Together, these parameters provide an estimate of the primary production and calcification on the reef. Initial data was collected in April of 2009 and shows substantial changes in TA and DIC from offshore to onshore and further cruises (4 per yr) will eventually provide seasonal variation in calcification and reef metabolism across the Florida reef tract. This important baseline data could provide an estimates of reef health that can be used to detect changes over time and eventually contribute to our understanding of how reefs respond to changing temperatures and ocean acidification.