A new NOAA study, published in the journal Ecological Modeling, forecasts an increase in ciguatera fish poisoning in the Gulf of Mexico and the U.S. Southeast Atlantic coast with predicted rising global ocean temperatures due to climate change. People can be affected by ciguatera, the most common form of algal-induced seafood poisoning, by eating contaminated tropical marine reef fish such as grouper, snapper and barracuda. Scientists are now predicting that global climate change will ciguatera, a nasty and incurable foodborne illness.
Ciguatera is caused by eating tropical reef fish (such as grouper, snapper and barracuda) that have been contaminated with toxins from marine microalgae. It can result in nausea, vomiting and even some neurologic symptoms, including tingling fingers or toes and a reversed sense of hot and cold temperatures. The fish can become contaminated with ciguatoxins, potent neurotoxins produced by Gambierdiscus, a microscopic algae common in the tropics. Ciguatera-causing algae are abundant in the Caribbean, and ocean warming would enable some of those species to move northward, increasing its presence in the Gulf of Mexico and U.S. southeast Atlantic. Warmer temperatures could also mean larger and longer blooms of harmful algae, including those that produce ciguatoxins. “Contaminated fish have no specific taste, color, or smell and there is no easy method for measuring ciguatoxins,” said Steve Kibler, a NOAA scientist and the study’s lead author, in the release. “However, we can forecast risk based on where and when we are likely to find the algae that produce ciguatoxins.”
In the Caribbean, Gambierdiscus are already near the top of their preferred temperature range. Higher temperatures are likely to inhibit the growth of these cells, slightly decreasing the risk of ciguatera in the Caribbean. For this study, researchers projected water temperatures in the greater Caribbean through the year 2099, based on 11 global climate models and data from NOAA buoys in the Caribbean and Gulf of Mexico. Forecasted temperature changes were then used to project the effects of ocean warming on the growth, abundance and distribution of two groups of ciguatera-causing algae (Gambierdiscus and Fukuyoa). More than 400 fish species are known to become toxic. In U.S. waters, ciguatera occurs in Hawaii, Guam, southern Florida, Puerto Rico, the U.S. Virgin Islands, and occasionally in the Gulf of Mexico, extending around the southeast U.S. coast as far north as North Carolina. Ciguatera impedes development of fisheries resources in many regions of the world. Toxins produced by Gambierdiscus contaminate marine animals such as corals and seaweeds, and the carnivores that feed upon them, causing toxins to move into the food chain. The forecast will allow communities to target monitoring, saving resources by focusing only on areas and times when ciguatera is likely to be present.
This work is part of a larger NOAA effort to develop and implement practical, affordable, and sustainable strategies for managing the risk of ciguatera. Next steps include determining which species are producing the toxins and developing and transferring monitoring technology to managers and researchers in tropical countries around the world.
For more information please visit: www.noaanews.noaa.gov
