General Information

Event name: US-91-003
Nature of the harmful event:
Water Discoloration , Other ( Flocculent deposits.)
Event directly affected:
Toxicity detected: No
Associated syndrome:
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (Summer diatom blooms have occurred in this area for the past several years.)
Individuals to contact: OLSEN, Paul

Location & Date

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Location: Latitude: , Longitude:
General location information: Sandy Hook Bay., New York.
HAB Area code(s): US-09
Additional location information: Sandy Hook Bay (component of Hudson-Raritan estuary).
Bloom event dates (yyyy/mm/dd): Event Date:1991-07-30
Start: 1991-07-20, End: 1991-08-01
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Peak July 30.


Causative organism known: Yes
Causative Species/Genus: Thalassiosira nordenskioldii ( cells/L)
Chaetoceros socialis ( cells/L)
Leptocylindrus minimus ( cells/L)
Cyclotella sp. ( cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: > 50 g/L Chl. µg/l
Additional bloom information: concentrations of individual species to 50,000,000 cells/L.
Event-related bibliography:

Environmental Conditions

Weather: Warm, clear. Turbidity (NTU): Wind direction:
Stratified water: Yes 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: Advected
In situ
Growth Comments Primarily in-situ, possibly from adjacent neritic waters.
Additional Environmental information: Water clear but becoming turbid; generally shallow (<5 m). Slight stratification in deeper areas.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Increase surveillance by the Monmouth County Health Dept. in liaison with NJDEP.
Additional harmful effect information: Brown water, subsequent flocculent deposits, especially in south shore vicinity (Keansburg to Atlantic Highlands)