Key environmental factors in the management of ciguatera

Ciguatera is a tropical illness that has expanded its geographic range through international travel, frozen tropical fish exports and the expansion of ciguatera-causing dinoflagellates into temperate coastal marine habitats. The drivers in the distribution of Gambierdiscus spp. and other ciguatera-causing dinoflagellates on their macroalgal substrates were investigated in this study. Palatability and macroalgal growth morphology were identified as important drivers in the heterogenetic distribution of Gambierdiscus populations. Higher Gambierdiscus densities were not always associated with fish-palatable macroalgal substrates. At mid-reef sites, Gambierdiscus populations were only found on flattened macroalgal substrates that were palatable to gastropods. Although there was no trend in substrate preference, there were site-specific preferences. This needs further investigation to identify environmental factors that influence the composition and distribution of macroalgae and thereby the potential expansion of ciguateracausing dinoflagellates into new coastal marine habitats. This research is essential in developing ciguatera monitoring tools as marine fisheries are an integral part of the economy, diet and lifestyle of coastal populations throughout the world.