General Information

Event name: US-17-027
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Other ( liver toxin production)
Event directly affected:
Toxicity detected: Yes
Associated syndrome: OTHER
Unexplained toxicity:
Species implicated in toxin transmission (transvector): Previous blooms have resulted in impacts to dogs, birds and muskrats in Maryland. Peak microcystin in Lake Needwood was 6750 ppb (August 5) and Northwest Creek had >300 ppb (Oct 14).
Report the outcome of a monitoring programme: Yes (Maryland Phytoplankton Monitoring Program)
Event occurred before in this location: Yes (Lake Needwood No-contact advisories in 2009, 2010, 2012-17; Northwest Creek (Kent Island) no-contact advisories in 2012-14, (no samples in 2015), 2016 & 2017)
Individuals to contact: WAZNIAK, Cathy

Location & Date

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Location: Latitude: , Longitude:
General location information: Lake Needwood and Northwest Creek (non-tidal areas in MD),
HAB Area code(s): US-10
Additional location information: Toxic blooms resulted in no-contact advisories placed on these waterbodies. Masonville cove (a restoration area) also exceeded microcystin action levels. Threshold in MD is 10 ppb and the bloom threshold for Microcystis is 40,000 c/mL. NW creek Aug-Oct
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd): First detection: 2017-06-15, End: 2017-06-18
Additional date-related information: Sassafras River exceeded bloom levels


Causative organism known: Yes
Causative Species/Genus: Microcystis aeruginosa (1.1x10^10 cells/L)
At Lake Needwood
Microcystis aeruginosa (1.2x10^9 cells/L)
At Northwest Creek
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography:

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity:
Nutrient information:
Temperature Range During Event: Max: °C, Min: °C
Salinity Range During Event:
Bloom location in the water column:
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision:
Additional harmful effect information:
Created at 04:42 on 24 Apr 2018