RED TIDE - CANADA: (ST. LAWRENCE ESTUARY)

A toxic algal bloom, also known as red tide, some 600 square kilometers [232 square miles] in size, developed early August [2008] in the St. Lawrence Estuary (SLE), Quebec, Canada, and resulted in an unprecedented faunal mortality event in the SLE. _Alexandrium tamarense_, a toxic dinoflagellate, naturally present in the SLE and Gulf of St. Lawrence can bloom when temperature rises and salinity decreases in surface waters as a result of increased freshwater runoff in the St. Lawrence River and coastal tributaries. _Alexandrium tamarense_ produces saxitoxin that affects the nervous system of fish, birds, and mammals and can cause paralytic shellfish poisoning (PSP) following consumption of toxin-contaminated organisms.At the end of July and in early August [2008] heavy precipitation, warm temperatures and calm surface waters favored the blooming of the dinoflagellate at the mouth of the Saquenay River. On 8 Aug 2008 about 100 dead birds (8 different species) were 1st observed by Parks Canada staff near Tadoussac at the confluence of the Saquenay River and St. Lawrence Estuary. As the bloom drifted towards the south shore of the St. Lawrence Estuary and moved eastward with the Gaspe current, numerous dead fish, birds, whales and seals were observed floating dead or stranded dead on shore. The bloom dissipated due to strong winds during the week of 18 Aug 2008 as it reached the Gulf of St. Lawrence.During the toxic algal bloom the Canadian Department of Fisheries and Oceans (DFO) closed all the shellfish harvesting areas in the affected zone to protect public health. The Canadian Food Inspection Agency (CFIA) monitors various shellfish sites in the SLE and advises closure when levels of toxin in shellfish exceed the accepted norm. As a precaution the CFIA and Health Canada advised the public against eating the liver and viscera of fish and invertebrates caught in the SLE during the red tide event and advised against eating the viscera of waterfowl hunted this fall. Saxitoxin accumulates in the digestive system of affected organisms but not in the flesh. Shellfish harvesting sites will open to the public when monitoring indicates consumption is safe, some sites have opened already.