General Information

Event name: CA-92-009
Country: CANADA
Nature of the harmful event:
High Phyto concentration
Event directly affected:
Toxicity detected: No
Associated syndrome: DSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (Although blooms of Dinophysis acuminata and Dinophysis novegica occur each summer in the St. Lawrence, the concentrations recorded in 1992 were exceptionnaly high.)
Individuals to contact: HUPPERTZ, Béatrice , LEVASSEUR, Maurice

Location & Date

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Location: Latitude: , Longitude:
General location information: South coast St. Lawrence Estuary, Québec Region
HAB Area code(s): CA-07
Additional location information: Lower St. Lawrence Estuary and the north part of the Gulf of St. Lawrence, Quebec, Canada
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Late May- mid November (during all the sampling period)


Causative organism known: Yes
Causative Species/Genus: Dinophysis norvegica (97,585 cells/L)
July 16th maximum concentration
Dinophysis acuminata (76,281 cells/L)
August 16th, maximum concentration
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: - D. acuminata dominant species in the St. Lawrence Estuary. Observed between May 31 and September 27. - D. norvegica dominant species in the south part of the region. Observed between June 2 and November 15.
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: 21 °C, Min: 1 °C
Salinity Range During Event: Max: 31, Min: 10
Bloom location in the water column:
In situ
Growth Comments Dinophysis acuminata and Dinophysis norvegica were found throughout the region, presumably as a result of in situ growth.
Additional Environmental information: D. acuminata - Temp range: 1-17.5º C (16º C during the bloom) - S ‰ range: 10-31‰ (26.5‰ during the bloom). D. norvegica: - Temp range: 1-21º C (9º C during the bloom) - S ‰ range: 16-31‰ (28‰ during the bloom).

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: None.
Additional harmful effect information: No diarrehic intoxications have been reported in spite of the very high concentrations of Dinophysis acuminata and Dinophysis norvegica. However, shellfish consumption was prohibited in most of the area due to PSP.
Updated at 08:46 on 25 Sep 2013