General Information

Event name: CA-94-001
Country: CANADA
Nature of the harmful event:
Seafood toxins
Event directly affected:
Shellfish , Humans
Toxicity detected: Yes (Approximate range: 4.0 g DTX-1 /g digestive gland.)
Associated syndrome: DSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): Blue mussels collected from wild sites.
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: No
Individuals to contact: PARANJAPE, Madhu A. , POWELL, J. Conrad , McKENZIE, Cynthia

Location & Date

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Location: Latitude: , Longitude:
General location information: Bonavista Bay, Newfoundland Region
HAB Area code(s): CA-28
Additional location information: Various sites in Bonavista Bay.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Late October 1993.


Causative organism known: Yes
Causative Species/Genus: Dinophysis norvegica ( cells/L)
Prorocentrum sp. ( cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Dinophysis norvegica implicated. Other potentially toxic species of dinoflagellate Prorocentrum sp. were also present in small numbers.
Event-related bibliography:

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: Oxygen content (nL/L): Wind velocity:
Temperature (°C): 6 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:
In situ
Growth Comments Unknown. Dinophysis sp., Prorocentrum, and other species of dinoflagellates are usually common in the fall months in this area. Therefore, in situ growth is implied.
Additional Environmental information: Water column well mixed and isothermal.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Blue mussels Okadaic Acid OA Trace LC
Blue mussels (digestive gland) Okadaic Acid DTX1 400 LC
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: Entire Bay closed for all shellfish harvesting and reopened in August 1994. Closure order NTN-1994-13 revoked NTN-1994-6 NTN-1994-6 revoked NTN-1993-11. NTN-1994-13 reopened the area to harvesting on August 8 1994.
Additional harmful effect information:
Updated at 07:37 on 10 Jun 2019