West Coast algae bloom

Satellite imagery provided by NASA Earth Observations taken July 18, 2015 and enhanced to show the algae bloom off the west coast of Vancouver Island. The algae blooms show as green in the blue ocean areas, with the deeper the green the denser the algae bloom; white areas in the lower left of the image are clouds.

Satellite imagery provided by NASA Earth Observations taken July 18, 2015 and enhanced to show the algae bloom off the west coast of Vancouver Island. The algae blooms show as green in the blue ocean areas, with the deeper the green the denser the algae bloom; white areas in the lower left of the image are clouds.

An algae bloom with unusual characteristics is occurring off the west coast of Canada and the United States. The bloom contains algae species which produce domoic acid. Domoic acid can accumulate in shellfish and harm the health of humans who eat them.

The intensity of this bloom (in terms of toxicity and therefore impacts to the ecosystem) is greater in U.S. than Canadian waters. Reasons for this are not known but may be due to different coastal circulation patterns in Canada and the U.S.

The U.S. is monitoring toxin levels in its waters and has imposed fisheries and aquaculture site closures along its coast. Fisheries and Oceans Canada (DFO) noted two small areas with slightly elevated levels of domoic acid in British Columbia and implemented closures that have since been lifted. DFO continues to monitor levels of domoic acid, but has not seen the levels reported in the U.S.

Algae blooms are regular occurrences along the B.C. coast at any time of year, but especially in late summer. This bloom occurred earlier in the year than normal and has lasted longer than normal (from late May into August). It has also occurred over a much larger area than usual (from California to Alaska).

DFO conducts ongoing studies into the biology of algae blooms and shares this information with the Canadian Food Inspection Agency (CFIA), which leads toxicity monitoring around shellfish and aquaculture sites. DFO and CFIA continue to monitor ocean conditions off the west coast of B.C. to verify the health of the aquatic ecosystem.

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