Dissolved inorganic nitrogen, dissolved organic carbon, and chloropyll-a from the Middle Keys of Florida Bay during 2017-2018, following the passage of Hurricane Irma

These data are tabular results of investigations focused on temporal changes in dissolved inorganic nitrogen (DIN) over a 15-month period starting in October 2017, following the passage of Hurricane Irma over the Middle Keys, Florida, United States. Post-Irma time-series measurements focused on determination of the impacts of episodic storm events on temporal variability in DIN.

Three areas in Florida Bay north of the Middle Keys were chosen for sampling based on previous work conducted between 2012 and 2015 by colleagues at the University of North Carolina (UNC) and FWC-M. Together, the study sites are representative of the range of nearshore environments along the southern portion of Florida Bay. Monthly whole water samples were filtered for chlorophyll-a (Chl-a) measurements, then analyzed for nitrate/nitrite (NOx-) and ammonium (NH4+). Drastic, systematic changes in all water quality parameters initially occurred, including spiked DIN concentrations following release of NH4+-enriched pore-waters during sediment resuspension and rapid declines in DIN during phytoplankton blooms. However, four months post-Irma, concentrations returned to seasonally variable pre-Irma levels observed in previous multi-year surveys.