General Information

Event name: CA-02-002
Country: CANADA
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: up to 200 ppm (µg/g) DA.)
Associated syndrome: ASP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (Canadian Shellfish Sanitation Program of the Canadian Food Inspection Agency)
Event occurred before in this location: No
Individuals to contact: BATES, Stephen S. , WHITE, John

Location & Date

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Location: Latitude: , Longitude:
General location information: North shore of Prince Edward Island, Gulf Region
HAB Area code(s): CA-25
Additional location information: CA-24 and CA-25This closure was the largest on record due to domoic acid, and it covered the majority of the southern Gulf of St. Lawrence.
Bloom event dates (yyyy/mm/dd): Start: 2002-04-05, End: 2002-05-10
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Domoic acid was first detected in Mytilus edulis (9.5 µg/g) from New London Bay (northern Prince Edward Island) on 5 March, 2002, indicating that the bloom had originated before that date. Few Pseudo-nitzschia seriata cells remained in the water by 28 May, 2002.


Causative organism known: Yes
Causative Species/Genus: Pseudo-nitzschia seriata (403,100 cells/L)
The max cell concentration was seen on 10 April, in New London Bay, northern Prince Edward Island. The highest cell concentration in New Brunswick was 303,000 cells/L, in Richibucto Bay, on 22 April, when the highest domoic acid concentration (200 µg/g)
Co-Ocurring Species/Genus: Pseudo-nitzschia delicatissima ( cells/L)
Pseudo-nitzschia pungens ( cells/L)
Pseudo-nitzschia pseudodelicatissima ( cells/L)
The co-occurring Pseudo-nitzschia species were found at only low proportions (generally < 15%), relative to the P. seriata.
Pseudo-nitzschia multiseries ( cells/L)
Chlorophyll concentration, if known: µg/l
Additional bloom information: This is the first closure due to domoic acid in the spring, along the coasts of northen Prince Edward Island, Baie des Chaleurs, eastern New Brunswick, and parts of Cape Breton Island, Nova Scotia. It is also the fist time that Pseudo-nitzschia seriata w
Event-related bibliography: Bates, S.S., C. Léger, J.M. White, N. MacNair, J.M. Ehrman, M. Levasseur, J.-Y. Couture, R. Gagnon, E. Bonneau, S. Michaud, G. Sauvé, K. Pauley, and Joël Chassé. 2002. Pennate diatom Pseudo-nitzschia seriata; domoic acid production causes spring closures of shellfish harvesting for the first time in the southern Gulf of St. Lawrence, eastern Canada, p. 7. 17th International Diatom Symposium, Ottawa, Ontario, August 25-30, 2002.Bates, S.S., C. Léger, J.M. White, N. MacNair, J.M. Ehrman, M. Levasseur, J.-Y. Couture, R. Gagnon, E. Bonneau, S. Michaud, G. Sauvé, , K. Pauley, and J. Chassé. 2002. Domoic acid production by the diatom Pseudo-nitzschia seriata causes spring closures of shellfish harvesting for the first time in the Gulf of St. Lawrence, eastern Canada, p. 23. Xth International Conference on Harmful Algae, St. Pete Beach, Florida, October 21-25, 2002.

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: No Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity: 0
Nutrient information:
Temperature Range During Event: Max: °C, Min: °C
Salinity Range During Event:
Bloom location in the water column: Whole column
Growth: Advected
Growth Comments The bloom was likely advected into the bays from the southern Gulf of St. Lawrence. It is also possible that some of the P. seriata cells had been growing on the undersurface of the sea ice at that time.
Additional Environmental information: The winter of 2001 - 2002 was anamolous, with above normal temperatures, a delay of freeze-up by 2-3 weeks, a total ice coverage 6th lowest on record, and an early departure of ice (at mid-March, it was 2 weeks early).

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Mya arenaria Domoic Acid DA eq 18.6 µg/g LC
Crassostrea virginica Domoic Acid DA eq 0.9 µg/g LC
Mytilus edulis Domoic Acid DA eq 200 µg/g LC
Kit used: Type of kit used:
Additional information: HPLC-DAD
Economic losses: A significant economic impact was felt by mussel and oyster harvesters and processers in the affected areas, due to the prolonged (almost 2 months) harvesting closure.
Management decision: Closure of affected harvesting area.
Additional harmful effect information: Domoic acid detected in blue mussels (Mytilus edulis), oysters (Crassostrea virginica), soft-shell clams (Mya arenaria), and the digestive gland plus mantle of sea scallops (Placopecten magellanicus). The oysters showed low levels of domoic acid only aft
Updated at 03:28 on 26 Sep 2013