This dataset contains carbonate system data collected by scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center to investigate the effects of carbon cycling, coastal and ocean acidification on the Tampa Bay estuary located in west central Florida and eastern Gulf of Mexico. Discrete seawater samples were collected periodically (every few weeks to months) at repeat monitoring locations. Water samples were analyzed by the USGS Carbon Analytical Laboratory in St. Petersburg Florida. This dataset contains time series measurements of carbonate system parameters including: water temperature (Celsius, C), salinity, dissolved oxygen (milligrams/L), total alkalinity (TA, micromoles/kg), dissolved inorganic carbon (DIC, micromoles/kg), pHT (pH on the total scale), nitrate + nitrite (NO3+NO2, micromoles/L), nitrite (NO2, micromoles/L), silicate (SIL, micromoles/L), ammonium (NH4, micromoles/L) and phosphate (PO4, micromoles/L).