Five kinds of harmful marine algal blooms are known to occur in Washington's coastal waters. PSP is caused by a suite of toxins produced by the marine alga Alexandrium. The toxins affect the neurological system, initially causing tingling, numbness or burning of the lips and tongue. If a significant amount of the toxin has been ingested, symptoms progress to a tingling of fingers and toes, loss of control in the arms and legs, giddiness, a rash, and finally, difficulty in breathing. In non-lethal cases, the symptoms may last several days.
Victims usually survive if life support is available.
Pseudo-nitzschia produces a toxin called domoic acid, which was first detected on the West Coast in 1991. Both shellfish and fish can accumulate domoic acid without ill effect. If ingested by humans, however, the toxin interferes with nerve signal transmission. Symptoms of ASP include nausea, vomiting, abdominal cramps and diarrhea. In severe cases, neurological symptoms appear, including dizziness, headache, seizures, disorientation, short-term memory loss, respiratory difficulty, coma and death.