Initial estuarine response to the nutrient-rich Piney Point release into Tampa Bay, Florida

From March 30th to April 9th, 2021, 814 million liters of legacy phosphate mining wastewater and marine dredge water from the Piney Point facility were released into lower Tampa Bay (Florida, USA). This resulted in an estimated addition of 186 metric tons of total nitrogen, exceeding typical annual external nitrogen load estimates to lower Tampa Bay in a matter of days. Elevated levels of phytoplankton (non-harmful diatoms) were first observed in April in the lower Bay. Filamentous cyanobacteria blooms (Dapis spp.) peaked in June, followed by a bloom of the red tide organism Karenia brevis. Reported fish kills tracked K. brevis concentrations, prompting cleanup of over 1600 metric tons of dead fish. Seagrasses had minimal changes over the study period. By comparing these results to baseline environmental monitoring data, we conclude that many of the biological responses observed after the release from Piney Point are abnormal relative to historic conditions.

Molecular Detection and Quantitation of the Red Tide Dinoflagellate Karenia brevis in the Marine Environment

ABSTRACT A real-time reverse transcription-PCR method targeting the rbcL gene was developed for the detection and quantitation of the Florida red tide organism, Karenia brevis. The assay was sensitive to less than 1 cell per reaction, did not detect rbcL from 38 nontarget taxa, and accurately quantitated K. brevis organisms in red tide samples from around Florida. These studies have resulted in a sensitive and specific method for K. brevis detection in the marine environment.