Alexandrium catenella

Alexandrium catenella is a type of tiny, single-celled marine organism called a dinoflagellate, often found in coastal waters. It naturally produces toxins that can accumulate in shellfish, like clams and mussels. When people eat contaminated shellfish, they can suffer from poisoning called paralytic shellfish poisoning (PSP), which affects the nervous system and can be serious. A. catenella blooms, or large population surges, can lead to vibrant red water called red tides. Monitoring and managing these blooms are important to protect public health, marine life, and the shellfish industry.