General Information

Event name: CA-90-005
Country: CANADA
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 2,218 - 5,468 µg STXeq / 100 g)
Associated syndrome: PSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (Toxic blooms reported annually since 1984; PSP toxic incidents known for more than 100 years in the region.)
Individuals to contact: HUPPERTZ, Béatrice

Location & Date

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Location: Latitude: , Longitude:
General location information: South coast St. Lawrence Estuary, Quebec Region
HAB Area code(s): CA-07
Additional location information: Mid-northern shore (49º14'N, 68º09'W) and lower southern shore (48º49'N, 68º10'W) of the St. Lawrence estuary and the southwestern Gulf of St. Lawrence (48º39'N, 64º26'W)
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Late June - early July


Causative organism known: Yes
Causative Species/Genus: Alexandrium excavatum (450,000 cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography:

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: 17 °C, Min: 9 °C
Salinity Range During Event: Max: 31, Min: 21
Bloom location in the water column:
Growth: Advected
In situ
Growth Comments Based upon circumstantial evidence from known water circulation patterns and benthic cyst distributions, it is likely that the Alexandrium spp. blooms found along the nothern shore of the st. Lawrence estuary represent endemic populations. The blooms alon
Additional Environmental information: Temperature range: 2 - 21º C (9 - 17º C during the bloom) Salinity range: 15 - 31‰ ( 21 - 31‰ during the bloom)

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Mya arenaria & Mytilus edulis Saxitoxins STX eq 2,218 - 5,468 Bioassay-Mouse
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: Periodic closures of recreational and commercial shellfish harvesting zones.
Additional harmful effect information: No human illness reported. PSP toxicity detected in soft-shell clams (Mya arenaria) and blue mussels (Mytilus edulis).
Updated at 08:48 on 25 Sep 2013