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. Discrete seawater samples were collected along spatial transects at one to four hour intervals over 24-hour time periods. Water samples were analyzed at the USGS Carbon Analytical Laboratory in St. Petersburg Florida. This data set 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, micromols/L), nitrite (NO2, micromols/L), silicate (SIL, micromols/L), ammonium (NH4, micromols/L) and phosphate (PO4, micromols/L).