General Information

Event name: US-20-002
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 40-69g/100g)
Associated syndrome: PSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (MA DMF Biotoxin Monitoring)
Event occurred before in this location: Yes (Nearly annual event)
Individuals to contact: O'NEIL, Terry

Location & Date

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Location: Latitude: , Longitude:
General location information: Nauset Estuary, Eastham, MA
HAB Area code(s): US-06
Additional location information: 1540 acre estuary on Cape Cod
Bloom event dates (yyyy/mm/dd): Start: 2020-03-19, End: 2020-05-28
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: All sp. except Mytilus reopened 4/30


Causative organism known: Yes
Causative Species/Genus: Alexandrium catenella ( 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: Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity:
Nutrient information:
Temperature Range During Event: Max: 12.2 °C, Min: 4.4 °C
Salinity Range During Event: Max: 33, Min: 23
Bloom location in the water column: Whole column
In situ
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Blue mussels Saxitoxins 69g/100g Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses: Commercial and recreational shellfisheries in Nauset estuary closed for 43 days.
Management decision: Estuary closed to shellfishing 3/19/20 through 4/30/20 for all species (Mussels remained closed until 5/28/20).
Additional harmful effect information:
Created at 09:52 on 19 Apr 2021