This is a request for TAC review of a draft document presented to TBEP by FWRI titled Effects of the Toxic Dinoflagellate Pyrodinium bahamense on Feeding Efficiency and Toxicity in Bivalve Grazers." Please send any comments or questions to Gary Raulerson (This email address is being protected from spambots. You need JavaScript enabled to view it.) on or before Sept. 6, 2019.


Blooms of Pyrodinium bahamense have been occurring on an annual (summertime) basis in Old Tampa Bay since the early 2000s, with severe blooms occurring on occasion. These blooms, similar to other harmful algal species such as red tide, can cause both fish kills and create health issues for humans, both through respiratory problems and the potential for saxitoxins to cause direct illnesses after consumption of affected fish.

An FWRI study completed in 2016 (partly funded through TBERF) characterized seeding potential of Pyrodinium bahamense cyst beds occurring in Old Tampa Bay. Some preliminary research has indicated that severe blooms of P. bahamense result from a combination of stormwater events and physical water quality conditions in Old Tampa Bay. Creation of shellfish (e.g., American oyster, Crassostrea virginica, and Quahog clam, Mercenaria campechiensis) nurseries that could compete with the dinoflagellate for nutrients or directly consume the microorganism is a potential management solution for P. bahamense, but requires additional research within Tampa Bay to understand potential effectiveness and limitations.


1) Identify native shellfish species capable of survival during P. bahamense blooms in aquarium settings.
2) Investigate potential for those shellfish species to interfere with one or more life cycle stages of P. bahamense.
3) With input from the TBEP Technical Advisory Committee, determine next steps, including potential for larger scale (in-situ) experiments in Old Tampa Bay.

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Download this file (Pyrodinium_Grazing_Project-DRAFT-FinalReport_8-26-19-b.pdf)Pyrodinium_Grazing_Project-DRAFT-FinalReport_8-26-19-b.pdf   2049 kB

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