General Information

Event name: CA-99-001
Country: CANADA
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 550 µg DA / g (August 5) in scallops liver.)
Associated syndrome: ASP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: No
Event occurred before in this location: No
Individuals to contact: BONNEAU, Esther , LEVASSEUR, Maurice , SAUVÉ, Gilbert

Location & Date

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Location: Latitude: 47.466667, Longitude: -61.799722
General location information: Iles-de-la-Madeleine, Quebec Region
HAB Area code(s): CA-23
Additional location information:
Bloom event dates (yyyy/mm/dd): Start: 1999-06-09,
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Final date, end of August 1999.


Causative organism known: Yes
Causative Species/Genus: Pseudo-nitzschia delicatissima (1,750 cells/L)
Pseudo-nitzschia seriata (12,000 cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: The DA outbreak coincided with small peaks of Pseudo-nitzschia seriata (12000 cells/l) and P. delicatissima (1750 cells/l) in the Laguna of Havre-aux-Maisons (sampling site of the DFO monitoring program). These cells were probably advected in the Laguna.
Event-related bibliography:

Environmental Conditions

Weather: Turbidity (NTU): Wind direction: NW
Stratified water: No Oxygen content (nL/L): Wind velocity: 10-15
Temperature (°C): 14,1 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:
Growth: Advected
In situ
Growth Comments Pseudo-nitzschia spp. cells were probably growing offshore (in the central part of the Gulf) and a part of the population was advected in the Laguna.
Additional Environmental information: Maximum Pseudo-nitzschia seriata cells abundance coincide with water temperature of 14.1°C. The wind was 10-15 km/h NW.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Scallop (liver) Domoic Acid DA eq 550 µg/g Bioassay-Mouse
Clams Domoic Acid DA eq Bioassay-Mouse
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: The Government of Quebec (Ministère de l’agriculture, des pêcheries et de l’alimentation – MAPAQ) sent a warning to the media to inform the public of the potential health tread of consuming whole scallops.
Additional harmful effect information: First detection of domoic acid in scallops liver on June 9. Maximum toxicity (550 µg DA/g) was measured on August 5 in scallops liver. Scallops were still toxic at the end of August. Scallops were harvested around the Islands. DA was also measured in blue
Updated at 02:28 on 26 Sep 2013