toxin accumulation

What Is Paralytic Shellfish Poisoning Caused By? Causes. Paralytic shellfish poisoning is caused from the ingestion of toxin-contaminated bivalve shellfish and crustaceans. Algal blooms of dinoflagellates, usually during the warmer months of June to October, result in toxin accumulation in filter feeders such as bivalves. What toxins are in shellfish? Five main types of shellfish