John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Introducing a nauseating illness that makes hot things feel cold and cold things feel hot.
Feast on a fish that’s consumed a special kind of microorganism and you might start experiencing peculiar symptoms: nausea, vomiting, tingling in the extremities, and for the real lucky ones, a disorienting sensation that makes “cold things feel hot and hot things feel cold” (per the CDC).
These are the trademarks of Ciguatera poisoning, caused by dining on a fish that itself has dined on neurotoxin-producing Gambierdiscus toxicus algae, which abound in the balmy waters of the Caribbean. Though symptoms usually go away in a few days, in some cases they persist for years, and there is no known cure. Fish that have been implicated in cases of Ciguatera include many restaurant favorites, including varieties of grouper, amberjack, and snapper.
With the oceans warming like a jacuzzi, residents of the Southeast and Gulf coasts can expect to see many more cases of this retching malady, according to a study from NOAA and others. That’s because the algae will be able to live farther north as the seas get hotter, and the fish that eat them will more often wind up in our nets. Here’s more from NOAA:
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.
“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. “However, we can forecast risk based on where and when we are likely to find the algae that produce ciguatoxins.” The forecast will allow communities to target monitoring, saving resources by focusing only on areas and times when ciguatera is likely to be present.
Chalk this one down as another dismal health implication of warmer oceans, right next to the algal neurotoxins that’ve kneecapped this year’s West Coast crabbing season.