
Harmful algal blooms (HABs) in the Gulf of Maine are caused by the dinoflagellate Alexandrium fundyense. In the early spring, this organism leaves the seafloor sediment as dormant cysts germinate or "hatch," swims toward the surface, and divides again and again to form a “bloom” or red tide. As the bloom ages, new cysts are formed that fall to the ocean bottom where they remain until they germinate the next year to restart the process. (Illustration by Jack Cook, Woods Hole Oceanographic Institution)[back] |