General Information

Event name: US-93-003
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 100-400 g/100 g shellfish.)
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 (Anual event in most years since Sept. 1972, usually in May/June, but may also occur later in summer and early autumn. Outbreaks on the 'South Shore' are more sporadic than the 'North Shore'. For instance, in 1991 and 1992 there was no occurrence of shellfish toxicity on the 'South Shore', while in 1993, there was a rather large protracted bloom probably due to increased spring runoff compard to the previous two years.)
Individuals to contact: ANDERSON, Donald M.

Location & Date

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Location: Latitude: , Longitude:
General location information: , Massachusetts.
HAB Area code(s): US-03
Additional location information: 'North Shore' of Massachusetts- Cape Ann to the northern MA border. 'South Shore' of Massachusetts - communities directly south of Boston Cape Cod salt ponds.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: mid-May through early July.


Causative organism known: Yes
Causative Species/Genus: Alexandrium fundyense (100 - 1,00 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: Yes 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: 10 °C, Min: 8 °C
Salinity Range During Event: Max: 30, Min: 25
Bloom location in the water column:
Growth: Advected
In situ
Growth Comments Dource-most likely southern Maine coastal waters; cells were presumably advected southward and alongshore into Massachusetts coastal water via a buoyant coastal plume or surface current formed from spring run-off. In situ growth may have occurred during t
Additional Environmental information: Stratification mostly due to spring run off, not local heating. Nutrients: Data not yet available.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: No Type of kit used:
Additional information: - Shellfish toxicity on both North and South Shores (100-400 g/100 g shellfish) - Mytilus edulis, Mya arenaria, and others. - Longer shellfish toxicity event than usual near the South Shore (see additional comments).
Economic losses:
Management decision: - Closure of shellfish beds (> 80 g toxin/100 g shellfish) May. - Reopened shellfish beds when toxins in shellfish were not detectable for 3 consecutive weeks detection limit (40 g toxin /100 g shellfish) - June and July
Additional harmful effect information: - Shellfish toxicity barely detectable in several Cape Cod salt ponds; ponds already closed due to high coliform.