his species produces paralytic shellfish poisons, mainly sulfamate saxitoxin derivatives, which accumulate in shellfish such as oysters, mussels and scallops, and thus can cause neurological and gastrointestinal problems in human shellfish consumers. Shellfish containing more than 80 micrograms toxin per 100 g meat should be considered unsafe for human consumption (Hallegraeff, 1991). Harmful species