Harmful Algal Information System: Event US-91-007

General Information

Event name:	US-91-007
Country:	UNITED STATES
Nature of the harmful event:	Mass mortalities
Event directly affected:	Shellfish
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 (Suspected but not documented.)
Individuals to contact:	BURKHOLDER, Joann , NOGA, E.

Location & Date

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Location:	Latitude: , Longitude:
General location information:	Pamlico River, Taylor Creek, etc ..., North Carolina. HAB Area code(s): US-11
Additional location information:	Pamlico River (6 stations), Taylor Creek, Lee Brothers Aquaculture Aurora Facility, Nense River (2 stations). Also: NC Maritime Museum (all fish species in holding tank), Jan. 1992, and National Marine Fisheries Service, Beaufort (Menhaden tank), Feb. 1992.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:	15 May, 4 Aug, 10 (?) Sep, 7-20 Oct, 15 Dec, 1991.

Microalgae

Causative organism known:	Yes
Causative Species/Genus:	Pfiesteria piscicida Steidinger et Burkholder 1996 ( cells/L) Previously reported as Pfiesteria, however, Karlodinium is now believed to be the causative species
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known:	µg/l
Additional bloom information:	Alga may be a new species within genus Alexandrium (K. Steidinger is helping to get the plate formula for formal speciation). Note-subsequently identified as Pfiesteria piscicida Quickly encysts and settles out once fish are dead. Cysts characteristics
Event-related bibliography:

Environmental Conditions

Weather:		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: 28 °C, Min: 12 °C

Salinity Range During Event:

Max: 35,

Bloom location in the water column:

Growth:

Growth Comments

Describe physical location: Various tributaries and acquaculture facilities as described previously.

Additional Environmental information:

Salinity range: 0/ppt (with water or high in Ca++) 35 ppt = kills as documented by Burkholder. Oxygen concentration: from low (approx 2 ppm) to approx 10 ppm. Water Column Stability: Unmixed, in shallow, turbid conditions.