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Coastal Watershed Institute
Florida Gulf Coast University
10501 FGCU Blvd S.
Fort Myers, FL 33965-6565

Phone: 239-590-7526

Mike Parsons


Ciguatera Research


Ciguatera Fish Poisoning (CFP) is a common form of seafood poisoning, affecting tens of thousands of people worldwide. People who consume reef-dwelling fish such as grouper, snapper, barracuda, hogfish, and triggerfish are potentially at risk. Although CFP is primarily a concern in tropical and sub-tropical coastal regions, the export of fish from these areas to markets in other regions creates a risk to fish consumers worldwide. One of the reasons why so many people are afflicted with CFP is because no simple screening method  currently exists, hindering efforts to monitor for CFP outbreaks and protect people from exposure to toxic fish. 

An international team of researchers headed by Michael Parsons of Florida Gulf Coast University, aims to better understand the factors that influence the occurrence of CFP, through a research project entitled “CiguaHAB”.  CiguaHAB is an anticipated 5-year project funded by NOAA’s Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) Program designed to investigate the conditions that lead to CFP outbreaks.


Ciguatera Fish Poisoning

CFP is caused by the consumption of fish which have accumulated toxins called ciguatoxins in their tissue. Ciguatoxins are heat-stable and therefore persist in the fish tissue even after being cooked. Ciguatoxins are produced by benthic dinoflagellates of the genus Gambierdiscus.  The dinoflagellates are epiphytic, meaning that they live attached to a host, most often benthic macroalgae. As these macroalgal hosts are consumed by herbivorous fish, the Gambierdiscus cells are consumed as well, and ciguatoxins are thereby introduced into the foodweb. From there, ciguatoxins are transferred to carnivorous fishes, eventually accumulating in the tissues of top predators. When people consume fish which have accumulated CTXs, they are at risk of CFP.

Common CFP symptoms include gastrointestinal problems like abdominal cramps, diarrhea, nausea, and vomiting followed by neurological symptoms. Headaches, muscle aches, and numbness are common; other symptoms may include strange sensations, such as the feeling of loose teeth, confusion between hot and cold temperatures, or a metallic taste in the mouth. Symptoms may persist for weeks or months. Death is rare, and usually associated with the consumption of whole fish, in which organs where toxins accumulate in higher concentrations are ingested.



An international team of experts from universities and laboratories around the Greater Caribbean Region has been assembled to investigate the conditions that lead to CFP outbreaks and create a model which will lead towards a better predictive capability and assist in elucidating the effects of global warming and other climactic or environmental perturbations on this important public health issue. In addition to Michael Parsons, Professor of Marine Science and Director of the Coastal Watershed Institute at Florida Gulf Coast University, the team includes Don Anderson and Mindy Richlen (Woods Hole Oceanographic Institution), Deana Erdner (University of Texas Marine Science Institute), Ron Kiene and Alison Robertson (University of South Alabama), Yuri Okolodkov (University of Veracruz, Mexico), and Tyler Smith (University of the Virgin Islands).

The primary objectives of this research are to: 

  • Characterize Gambierdiscus population diversity and connectivity on regional and local scales.
  • Determine effects of environmental factors on the growth and toxicity of representative strains of Gambierdiscus.
  • Investigate Gambierdiscus population dynamics and the environmental conditions that contribute to blooms in several locations for the study region.
  • Investigate the fate of ciguatera precursors, toxins and metabolites in the coral reef food web.
  • Model the population dynamics and toxin production of Gambierdiscus under different environmental forcings, including those associated with natural and human-induced perturbations such as pollution, reef destruction, and climate change.
  • Communicate project results and discuss applications to resource management with stakeholders in the GCR.

Field studies will take place at seven locations throughout the northern portion of the Greater Caribbean region (GCR). These sites were chosen to encompass the entire study region and to include areas known to host CFP outbreaks.