General Information

Event name: CA-91-003
Country: CANADA
Nature of the harmful event:
Seafood toxins
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 (Dinophysis norvegica and DTX-1 in mussels were previously found at the same location in early August, 1990.)
Individuals to contact: de FREITAS, Anthony

Location & Date

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Location: Latitude: , Longitude:
General location information: Halifax Eastern Shore, Scotia Fundy Region
HAB Area code(s): CA-17
Additional location information: Mahone Bay, Southern coast of Nova Scotia
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: May - June 91.


Causative organism known: Yes
Causative Species/Genus: Dinophysis norvegica ( 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: 12 °C, Min: 6 °C
Salinity Range During Event:
Bloom location in the water column:
Growth Comments Not known.
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Mytilus edulis Okadaic Acid OA eq LC
Mytilus edulis Okadaic Acid DTX1 LC
Kit used: Type of kit used:
Additional information: Low but detectable levels of DSP toxins were found in cultured mussels (Mytilus edulis). A 50:50 ratio of okadaic acid: DTX-1 two weeks later as levels began to drop. Levels in mussels became undetectable by early July. Plankton samples exhibited no detectable DSP toxins using ADAM & HPLC analysis, but the biomass of phytoplakton eas low by the time samples were collected for chemical analysis.
Economic losses:
Management decision: The low levels of DSP toxins forund did not justify an official closure of mussel harvesting, but the mussel growers in the area voluntarily stopped harvesting for about a two month period as a precautionary measure.
Additional harmful effect information:
Updated at 07:24 on 25 Sep 2013