Ciguatera fish poisoning (CFP) is the most common algal-borne illness worldwide. It is a debilitating syndrome caused by consumption of fish contaminated with ciguatoxins (CTXs) produced by the dinoflagellate Gambierdiscus. Understanding of CTX in marine food web dynamics is poor, as is identification of the truly toxic Gambierdiscus species/strains (e.g., the “super bugs”). We are characterizing CTX production and flux into Caribbean reef food webs for prediction and prevention of CFP.

Why We Care
Ciguatera fish poisoning (CFP) is the most prevalent algal-borne illness worldwide. Consuming tropical marine organisms (primarily fish) contaminated with ciguatoxins (CTXs) and related precursors, produced by benthic dinoflagellates in the genus Gambierdiscus, causes this debilitating human poisoning syndrome.

Ecological understanding and resulting management solutions for CFP lag far behind other harmful algal bloom syndromes due to a lack of information needed to identify the truly toxigenic Gambierdiscus species and strains (e.g., the “super bug”) and the CTX precursors produced by these species. Additionally, scientists have a poor understanding of how these precursors enter the marine food web and change once in it.

These knowledge gaps severely limit the ability of resource managers to monitor for and protect the public against CFP. To date, CFP forecasting and predictive capabilities are limited to non-existent, and responses are reactionary and ex post facto when CFP outbreaks occur.

What We Are Doing
Our overarching goal is to characterize CTX production and flux into Caribbean reef food webs. Specifically, our objectives are to:

1. determine the spatio-temporal population dynamics of newly characterized CTX-producing Gambierdiscus super bug species;
2. translate Gambierdiscus cellular toxicity into toxin body burden in reef herbivores; and
3. identify and characterize the environmental conditions and habitats that produce the highest abundances of Gambierdiscus super bugs.

We will integrate project results with a second-generation model of CTX flux into the reef food web to aid in management strategies to minimize human illness.

Dr. Michael Parsons of Florida Gulf Coast University leads this project along with co-leads Dr. Alison Robertson (University of South Alabama), Dr. Donald Anderson (Woods Hole Oceanographic Institution), Dr. Mindy Richlen (Woods Hole Oceanographic Institution), and Dr. Tyler Smith (University of the Virgin Islands). The project is funded through the NCCOS Ecology and Oceanography of Harmful Algal Bloom (ECOHAB) Program.