General Information

Event name: US-93-018
Nature of the harmful event:
Mass mortalities
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 (Chronic annual blooms.)
Individuals to contact: OLSEN, Paul

Location & Date

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Location: Latitude: , Longitude:
General location information: Raritan Bay, Cliffwood Beach to E. Keansburg, New Jersey.
HAB Area code(s): US-09
Additional location information: Raritan Bay south shore, Cliffwood Beach to E. Keansburg, especially dense in Keyport Harbor; also extending in lesser intensity, from Sandy Hook Bay along New Jersey coast to about Long Branch, with highest density at Sea Bright.
Bloom event dates (yyyy/mm/dd): Start: 1993-07-20, End: 1993-07-23
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: A few lesser blooms of same species reocurred in the bay during August.


Causative organism known: Yes
Causative Species/Genus: Katodinium rotundatum (100,000,00 cells/L)
Dominant species
Co-Ocurring Species/Genus: Olisthodiscus luteus (5,000,000 cells/L)
Subdominant species
Euglena sp. (5,000,000 cells/L)
Euglena/Eutrepia spp. Subdominant species
Chroomonas spp. ( cells/L)
Chlorophyll concentration, if known: Concurrent Chl concentrations exceed 50 g/L µg/l
Additional bloom information: Several other species present around 1,000,000 cell/L.
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: 24 °C, Min: 21 °C
Salinity Range During Event: Max: 29, Min: 17
Bloom location in the water column:
In situ
Growth Comments
Additional Environmental information: Salinity usually 22.3 - 25.5 ; dissolved oxygen usually supersaturated in blooms (10.9 - 15.9 mg/L) otherwise 6 -10 mg/L, but a low value of 3.6 mg/L associated with fishkill (see attached). Water column usually mixed although apparent lack of mixing c

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: Increased surveillance by NJDEP and USEPA: The Monmouth County Health Department in 1992 initiated a monitoring/sampling program for red tide; they acquired a Coast Guard Search & Rescue (30 ft) vessel which is necely adapted for marine biological work an
Additional harmful effect information: