General Information

Event name: US-95-006
Nature of the harmful event:
High Phyto concentration , Mass mortalities
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 (On our records from 1992-93, 1988-89, 1976, 1985, 1981 in the same general vicinity, within a 16 km segment from about Keyport to Atlantic Highlands.)
Individuals to contact: OLSEN, Paul

Location & Date

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Location: Latitude: , Longitude:
General location information: Raritan Bay to Sandy Hook Bay., New Jersey.
HAB Area code(s): US-09
Additional location information: New Jersey-Hudson/Raritan estuary, southern portion (Raritan Bay to Sandy Hook Bay) and a few locales along the adjacent New Jersey oceanfront.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Late May through June, mixed diatom blooms pervaded the area; 5-18 July, patchy but intense flagellate blooms occurred within the area.


Causative organism known: Yes
Causative Species/Genus: Skeletonema costatum ( cells/L)
Thalassiosira gravida ( cells/L)
Thalassiosira nordenskioldii ( cells/L)
Cerataulina pelagica ( cells/L)
Rhizosolenia delicatula ( cells/L)
Olisthodiscus luteus ( cells/L)
Katodinium rotundatum ( cells/L)
Prorocentrum spp. ( cells/L)
Eutreptia lanowii ( cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Dominant diatoms: individual cell counts to 40,000 cells/ml, total counts >100,000 cells/ml. Dominant flagellates: individual counts to 20,000, totals to 50,000.
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: 27 Current Velocity: 0
Nutrient information:
Temperature Range During Event: Max: 30 °C, Min: 24 °C
Salinity Range During Event:
Bloom location in the water column:
In situ
Growth Comments In-situ growth; some diatoms of neritic origin from adjacent New York Bight waters.
Additional Environmental information: Bottom dissolved oxygen as low as 0.4-1.1 mg/L at 2-4 m depth; night time surface dissolved oxygen as low as 0.28 mg/L at times and place of kills.

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: Response teams from NOAA (Sandy Hook), USEPA Region II, and Monmouth County Health Department, collected samples and field data ASAP after the kills; coordinated by New Jersey Department of Environmental Protection; routine surveillance increased.
Additional harmful effect information: Fish kills are attributed to hypoxia from bloom collapse and consequent algal decomposition in the several weeks preceding kills.