General Information

Event name: US-17-006
Nature of the harmful event:
High Phyto concentration
Event directly affected:
Toxicity detected: Yes (Approximate range: 0-5.7ppm)
Associated syndrome:
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (DMF Phytoplankton monitoring & Jefferson Turner's Lab (UMASS) Buzzards Bay Phytoplankton)
Event occurred before in this location: Yes
Individuals to contact: HICKEY, Mike , O'NEIL, Terry

Location & Date

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Location: Latitude: , Longitude:
General location information: Buzzards Bay, Nantucket Sound ++,
HAB Area code(s): US-07
Additional location information:
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Pseudo-nitzschia sp. (434000 cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: During this event DMF sent splits of all phytoplankton samples to Kate Hubbard, Ph.D. at the Florida Fish and Wildlife Conservation Commission, for species composition and quantitative toxin analyses. The results of her toxin analyses indicated extremely low levels of domoic acid in the phytoplankton. Results from Kate’s genetic species composition analyses showed that Massachusetts waters were dominated by Pseudo-nitzschia species that are not generally highly toxic. However, it is noteworthy that the species P. australis, which is known to be highly toxigenic, was identified for the first time in Massachusetts waters.
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: °C, Min: °C
Salinity Range During Event:
Bloom location in the water column: Whole column
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Blue mussels - Mytilus Edulis Domoic Acid 5.7 ppm Other
Kit used: Yes Type of kit used: Scotia
Additional information: Positive Scotia Kit tests of phytoplankton samples led to additional screening of shellfish meats (Blue Mussels and Oysters). All meats tested negative with the kits except two BM samples from Chilmark. DMF followed up on the two "positive" mussel samples with HPLC screening at the Rhode Island State Health Lab. The mussels came back with DA levels of 5.6 and 5.7 ppm. Mussels from these locations were retested a week later with HPLC and no DA was found.
Economic losses: None
Management decision: No closures were enacted during this bloom event in MA waters
Additional harmful effect information:
Created at 04:54 on 23 Apr 2018
Updated at 02:49 on 6 Feb 2020