Ciguatera in Abacos?

[GeneM]

Does anyone have good info on how to aviod ciguatera poisoning? I know to avoid old fish, bit I'm not real good at age guessing. I've been avoiding all reef fish, fearing getting sick. That leaves only deep water trolling. Is ciguatera only located in specific locations?

[Oohla]

Here you go:

Int J Food Microbiol. 2000 Nov 1;61(2-3):91-125.
Ciguatera: recent advances but the risk remains.

Lehane L1, Lewis RJ.
Author information
Abstract
Ciguatera is an important form of human poisoning caused by the consumption of seafood. The disease is characterised by gastrointestinal, neurological and cardiovascular disturbances. In cases of severe toxicity, paralysis, coma and death may occur. There is no immunity, and the toxins are cumulative. Symptoms may persist for months or years, or recur periodically. The epidemiology of ciguatera is complex and of central importance to the management and future use of marine resources. Ciguatera is an important medical entity in tropical and subtropical Pacific and Indian Ocean regions, and in the tropical Caribbean. As reef fish are increasingly exported to other areas, it has become a world health problem. The disease is under-reported and often misdiagnosed. Lipid-soluble, polyether toxins known as ciguatoxins accumulated in the muscles of certain subtropical and tropical marine finfish cause ciguatera. Ciguatoxins arise from biotransformation in the fish of less polar ciguatoxins (gambiertoxins) produced by Gambierdiscus toxicus, a marine dinoflagellate that lives on macroalgae, usually attached to dead coral. The toxins and their metabolites are concentrated in the food chain when carnivorous fish prey on smaller herbivorous fish. Humans are exposed at the end of the food chain. More than 400 species of fish can be vectors of ciguatoxins, but generally only a relatively small number of species are regularly incriminated in ciguatera. Ciguateric fish look, taste and smell normal, and detection of toxins in fish remains a problem. More than 20 precursor gambiertoxins and ciguatoxins have been identified in G. toxicus and in herbivorous and carnivorous fish. The toxins become more polar as they undergo oxidative metabolism and pass up the food chain. The main Pacific ciguatoxin (P-CTX-1) causes ciguatera at levels=0.1 microg/kg in the flesh of carnivorous fish. The main Caribbean ciguatoxin (C-CTX-1) is less polar and 10-fold less toxic than P-CTX-1. Ciguatoxins activate sodium ion (Na ) channels, causing cell membrane excitability and instability. Worldwide coral bleaching is now well documented, and there is a strong association between global warming and the bleaching and death of coral. This, together with natural environmental factors such as earthquakes and hurricanes, and man-made factors such as tourism, dock construction, sewage and eutrophication, may create more favourable environments for G. toxicus. While low levels of G. toxicus are found throughout tropical and subtropical waters, the presence of bloom numbers is unpredictable and patchy. Only certain genetic strains produce ciguatoxins, and environmental triggers for increasing toxin production are unknown.

[billknny]

GeneM,

Th simple answer is: There is no simple answer.

There are a couple of things you can do to limit the problem. Talk to the locals. They will have rules of thumb on how big a fish is too big (and old!) to risk eating as well as what kinds of fish you should avoid, and what are safe. If the local fisherman don't give you answers that you feel comfortable with, the local medical clinic can be a good source of information.

As a passionate fisherman (and sailor) I avoid shallow reef fish because we don't need them to fill the freezer. We stick to the pelagic fish, and to fish we catch deeper than 200 feet--all of which are generally considered safe in all areas.

[JPA Cate]

Bill, I'm sorry to say that your information is basically incorrect, at least for the South Pacific, where ciguatoxic poisoning is the main cause of death in young people (due to build up of the ciguatoxin in their livers) from repeated exposure to fish the locals think are safe.

If there is a rule of thumb, it is to avoid red snapper, coral trout, groupers and all but pan size fish, plus only eat pelagic fish you've caught more than 3 days out from a reef. Such a conservative rule of thumb will possibly see most people safe, for now. Even the pelagic fish, where they come in to feed on the smaller fish near reefs, may have enough ciguatoxin in their tissues to trigger an attack in a person who has already got a ciguatoxin build up in their system. If the author of the article posted above is correct, we will see an increase in species affected by ciguatoxin, and then there will be only a few safe ones left: the ones who live very deep, and the estuarial ones who do not eat reef fish, and cold water fish, where there is no ciguatera.

We have seen people near to death from ciguatoxic poisoning, although our own symptoms were not that bad...but we no longer even fish for the pelagics--BUT we know we have a loading dose such that even a mildly ciguatoxic fish could make us grievously ill. For those of you who think it couldn't happen to you, don't accept gift fish (our first incident), and don't trust the test kits (we got a false negative).

Ann

[GeneM]

Thanks for reaffirming my healthy fear.

Bill - You fish deeper than 200 ft. How is that done and what fish would I look for?