Red tide syndrome

One types of phytoplankton, called dinoflagellates, contains toxins. Sometimes a lot of dinoflagellates grow quickly in one area of the ocean. The large cloud of dinoflagellates turns the water reddish-brown. This called a red tide.

During this period of rapid growth, the algae produce potent toxins called breve-toxins which, when consumed by humans, causes classic shellfish poisoning.

Where fin fish do not become contaminated by these toxins, some shellfish do. For this reason, it is imperative that people do not eat oysters, mussels, clams, quahog, scallops and soft-shell crabs from waters affected by red tide.

Every year, approximately 3 cases of shellfish poisoning are reported in the United States, typically in the coastal regions of the Atlantic Northeast and Pacific Northwest. Shellfish toxicity was documented in1880 and aerosol-related respiratory symptoms in human inhabitants were described in 1917.
Red tide syndrome