General Information

Event name: US-89-021
Nature of the harmful event:
High Phyto concentration
Event directly affected:
Other Terrestrial
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: No
Individuals to contact: HANOWELL, Ray

Location & Date

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Location: Latitude: , Longitude:
General location information: Pierce county., Washington.
HAB Area code(s): US-24
Additional location information: American Lake.
Bloom event dates (yyyy/mm/dd): Event Date:1989-11-18
Start: 1989-11-18, End: 1990-01-10
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: 18 November 1989 (first reported animal illness) to present (10 January 1990). The toxic bloom is still present.


Causative organism known: Yes
Causative Species/Genus: Anabaena flos-aquae ( cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: The toxin is Anatoxin-A
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: 10 °C, Min: 9 °C
Salinity Range During Event:
Bloom location in the water column:
In situ
Growth Comments
Additional Environmental information: Specific conductivity has been measured from 118 to 147 µmhos/cm. A few fecal coliform samples have been collected and found to contain between 45 and 61 fc/100 ml. pH: 7.2 - 7.8.

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: Media notified; fact sheets distributed to residents around the lake, public access sites posted with warning signs. Some treatment was attempted using copper sulfate, but was, for the most part, ineffective.
Additional harmful effect information: As of 10 January 1990, there have been 5 dead cats, 1 ill cat, 1 dead dog, 5 ill dogs, and 3 waterfowl that are suspected to have been due to the algae. A few necropsys have been performed, but were inconclusive.