General Information

Event name: US-87-002
Nature of the harmful event:
Seafood toxins , Mass mortalities
Event directly affected:
Aquatic Mammals
Toxicity detected: Yes (Approximate range: 40 to 600 g STX /100 g of liver or viscera or about 20 g/kg fish.)
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 (This many whale deaths in a one month period is unprecedented in this region and perhaps globally as well.)
Individuals to contact: ANDERSON, Donald M.

Location & Date

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Location: Latitude: , Longitude:
General location information: Massachusetts and Cape Cod Bays., Massachusetts.
HAB Area code(s): US-05
Additional location information:
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: November-December.


Causative organism known: No
Causative Species/Genus:
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: 10 °C, Min: 6 °C
Salinity Range During Event: Max: 33, Min: 31
Bloom location in the water column:
Growth Comments
Additional Environmental information: Oxygen: normal.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Whale Saxitoxins STX eq 600 Bioassay-Mouse
Mackerel Saxitoxins STX eq 20 g/kg LC
Kit used: No Type of kit used:
Additional information: Saxitoxin has been posivitely identified (using mouse bioassay, HPLC, immunoassay, and TLC) in the viscera and liver of mackerel from the entire Gulf of Maine region and in the liver of some of the dead whales. Quantities range from 40 to 600 g / 100 g of liver or viscera, or about 20 g/kg fish. We have no knowledge of where and when the mackerel obtained their toxin. No toxin was detected in plankton tows in the areas where the whales were feeding.
Economic losses:
Management decision: Public health advisory issued warning consumers about consuming mackeresl, especially the viscera.
Additional harmful effect information: Saxitoxin in the mackeresl probably killed the whales, but the final proof will be difficult or impossible to obtain.