ABSTRACT
Molluscan shellfish have long been a gastronomic treat for humans, a delight that has tragically for some, ended in poisoning and even death. The cause of these poisoning’s can be twofold. First, poor food hygiene may lead to bacterial spoilage of the shellfish, resulting in human illness such as botulism (1), a type of poisoning not unique to shellfish. The second cause, which rarely occurs in other food sources and is the subject of this chapter, results from the shellfish sequestering toxic compounds. Many shellfish gain sus tenance by sieving the water column and feeding upon the minute organisms therein. At times the organisms comprising the shellfish’s diet are toxic, so as well as nutrients, shell fish consume compounds that are seemingly harmless to them (2,3) but are toxic to those organisms further up the food chain. These toxic microorganisms are present in the envi ronment as a matter of course, but are usually in numbers too low to present a problem. Their populations do on occasion bloom, intoxicating exposed shellfish to levels harmful to the consumer. These toxins can remain within the tissues of the shellfish for days, weeks, or months after exposure of the shellfish to the toxic microalgae.
