Alexandrium fundyense is a species of dinoflagellate, a type of single-celled organism found in marine environments. It is known for its role in harmful algal blooms, which can produce toxins that affect marine life and human health. These blooms often occur in coastal waters, particularly in the Gulf of Maine. This dinoflagellate thrives in nutrient-rich waters and can reproduce rapidly under favorable conditions. Monitoring Alexandrium fundyense is essential for managing fisheries and ensuring the safety of seafood, as its toxins can accumulate in shellfish, posing risks to consumers.