General Information

Event name: US-98-006
Nature of the harmful event:
Water Discoloration
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: Yes (The bloom was present throughout the entire Peconic system from 1985 through 1987, with densities occasionally exceeding 1,000,000 cells/ml. Cell numbers declined through 1988 and 1989, and were generally undetectable during 1990 with the exception of those from West Neck Bay. During 1991, densities of up to 2,000,000 cells/ml occurred in Flanders Bay and West Neck Bay. During 1992, numbers approached 850,000 cells/ml in Coecles Harbor and 1,000,000 cells/ml in West Neck Bay. It occurred briefly in May of 1994 in Flanders Bay (up to 14,000) cells/ml) and in Great Peconic Bay (11,000 cells/ml). During 1995 concentrations exceeded 1,000,000 cells/ml at 12 of 31 stations sampled, with a peak value of 1,7 00,000) recorded in July. During 1997, concentrations ranged from 1,600) to 380,000.)
Individuals to contact: NUZZI, Robert

Location & Date

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Location: Latitude: , Longitude:
General location information: West Neck Bay, Shelter Island, New York.
HAB Area code(s): US-08
Additional location information: Located within the Peconic Estuary System, on the eastern end of Long Island, New York.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: late May to mid-July .


Causative organism known: Yes
Causative Species/Genus: Aureococcus anophagefferens (50,000,000 cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: The organism was also present in other locations in the Peconic estuary, but at much lower concentrations.
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: 26 °C, Min: 20 °C
Salinity Range During Event: Max: 27, Min: 25
Bloom location in the water column:
In situ
Growth Comments
Additional Environmental information: Dissolved oxygen: 5.4 - 8.7 mg/L

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: Continue weely monitoring program.
Additional harmful effect information: Impacts on various shellfish species (scallops, hard clams & mussels) and on submerged aquatic vegetation (eelgrass) have previously been reported. Other effects are aesthetic - water discoloration and reduced transparency.