The rise of toxic tropical and subtropical marine dinoflagellates Gambierdiscus spp – distribution, ciguatoxins trophic transfer and risk of ciguatera fish poisoning


Funded by the Portuguese Foundation for Science and Technology (FCT) and European Regional Development Fund (ERFD)

Ciguatera fish poisoning (CFP) is one of the largest scale seafood poisonings affecting tens of thousands people every year worldwide.

Although ciguatera endemic areas are tropical and subtropical Indo-Pacific Ocean and Caribbean Sea, human poisoning episodes have been recently reported in Europe after consumption of fish caught in European waters, including Portuguese waters.

Ciguatoxins (CTXs) are highly potent natural neurotoxins produced by epi-benthic dinoflagellates of the genus Gambierdiscus. The toxins produced by this microalgae can be transferred into the marine trophic chain, primarily through herbivorous fish that feed on the macroalgae that serve as substrate for Gambierdiscus and in a second phase through carnivorous fish feeding on contaminated herbivores.

This project aims to improve knowledge on the distribution of the toxin-producing microalgae in the environment, to characterize dinoflagellates production of toxins and to investigate the fate of ciguatoxins in the food web, including understanding the pathways of biotransformation. Finally, the project aims to investigate the mechanisms underlying the prevalence of CTX in certain fish species in order to evaluate the risk of fish consumption.


To examine the distribution and seasonal variability of the toxic dinoflagellate Gambierdiscus spp. in Portuguese waters hotspots

To investigate the processes and pathways of marine food web transfer from toxin producers up to top predators

To investigate the risk related with fish consumption