General Information

Event name: US-07-018
Nature of the harmful event:
Water Discoloration , High Phyto concentration
Event directly affected:
Planktonic life
Toxicity detected: No
Associated syndrome:
Unexplained toxicity: Yes (Suspected juvenile fish kill association but no confirmation regarding cause)
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (Chesapeake Bay Monitoring Program, Virginia HAB Program)
Event occurred before in this location: Yes (A similar bloom occurred in these waters in 2006)
Individuals to contact: MARSHALL, Harold G.

Location & Date

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Location: Latitude: , Longitude:
General location information: Cgesaoeaje Vat, Virginia
HAB Area code(s): US-10
Additional location information: Potomac River from Colonial Beach downstream, bloom entered and persisted as a bloom within numerous shoreline inlets and several bays along its length.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Observations began June 13, 2007, concentrations reached 337,500 cells/ml on June 15, 2007 off Colonial Beach in the Potomac River. Molecular testing for species identification confirmed species was Karlodinium veneficum. Bloom levels continued to August 1, 2007. Detection at lower concentrations occurred into mid August.


Causative organism known: No
Causative Species/Genus: Karlodinium veneficum (337500000 cells/L)
See Above
Co-Ocurring Species/Genus: Akashiwo sanguinea (4600000 cells/L)
Also present was Heterocapsa rotundatum
Chlorophyll concentration, if known: µg/l
Additional bloom information: Other dinoflagellates present in lower numbers were Scrippsiella trochoidea, Gymnodinium sp. and Prorocentrum minimum
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: 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:
Additional harmful effect information: