General Information

Event name: US-97-006
Nature of the harmful event:
Mass mortalities
Event directly affected:
Toxicity detected: No
Associated syndrome: OTHER
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: No
Individuals to contact: ANDERSON, Donald M.

Location & Date

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Location: Latitude: , Longitude:
General location information: Chesapeake Bay., Maryland.
HAB Area code(s): US-10
Additional location information:
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: August-September.


Causative organism known: Yes
Causative Species/Genus: Pfiesteria sp. ( cells/L)
Previously reported as Pfiesteria, however, Karlodinium spp. is now believed to be the causative organism
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: It is also of note that taxonomic studies have revealed that there is a Pfiesteria complex which includes at least 3 morphotypes, some of which may be a different genus tentatively named Cryptoperidiniopsis. lt presently requires scanning electron microsc
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: °C, Min: °C
Salinity Range During Event:
Bloom location in the water column:
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: Five tributaries were closed to fishing and recreational activities.
Additional harmful effect information:
Updated at 06:00 on 3 Apr 2019