General Information

Event name: US-09-017
Nature of the harmful event:
Water Discoloration , High Phyto concentration
Event directly affected:
Planktonic life , Humans
Toxicity detected: No
Associated syndrome:
Unexplained toxicity:
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (Va. Dept. Health, Va. Dept. Environmental Quality)
Event occurred before in this location: Yes (this species occurs in bloom concentrations in these waters annually during late summer to early autumn)
Individuals to contact: MARSHALL, Harold G.

Location & Date

[View larger map]
Location: Latitude: 36.965556, Longitude: -76.468611
General location information: Chesapeake Bay Estuary, Virginia
HAB Area code(s): US-10
Additional location information: Virginia rivers: LaFayette, Elizabeth, lower James and lower Chesapeake Bay. Begins in small creeks and inlets, spread into regional rivers and carried by river flow into lower Chesapeake bay.
Bloom event dates (yyyy/mm/dd): Start: 2009/07/31, End: 2009/09/01
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Cochlodinium polykrikoides (1,652,000 cells/L)
dense surface concentrations
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography: Marshall et al. 2008; 2009

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: Yes Oxygen content (nL/L): 6.94 Wind velocity:
Temperature (°C): 27.5 Oxygen saturation %: Current Direction:
Sechhi disk (m): 0.3 Salinity: 15.3 Current Velocity:
Nutrient information:
Temperature Range During Event: Max: 29.2 °C, Min: 27.3 °C
Salinity Range During Event: Max: 23.3, Min: 12.3
Bloom location in the water column:
In situ
Growth Comments
Additional Environmental information: discoloration of water, odor

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: