True or false? Ciguatera is a naturally occurring chemical hazard in large reef fish.

Ciguatera is indeed classified as a naturally occurring chemical hazard that can affect large reef fish. It is caused by the accumulation of toxins produced by algal blooms, specifically the dinoflagellates that can be present in marine environments. Larger fish, such as barracuda and grouper, tend to accumulate these toxins as they consume smaller fish that have fed on the toxic algae, leading to higher concentrations in their tissues.

When humans consume these fish, they may experience ciguatera poisoning, which can cause various symptoms ranging from gastrointestinal issues to neurological effects. The fact that the toxins are not linked to any form of human manipulation or contamination but rather arise naturally from the environment is what categorizes ciguatera as a chemical hazard.

Thus, stating that ciguatera is a naturally occurring chemical hazard in large reef fish is accurate, reinforcing that the answer is true.