EOLakeWatch: Interactive algal bloom monitoring tool

The latest images of satellite-derived chlorophyll-a and derived algal bloom indices, as well as historical bloom conditions, can be viewed in the EOLakeWatch web tool below for select Canadian lakes.

Data to produce the interactive dashboard can be found under Water Quality Remote Sensing within the government's Open Government portal.

How to use the interactive algal bloom monitoring tool
  1. Click on your lake of interest in the map area
  2. Select the algal bloom index to display in the graph area (bloom extent, intensity, or severity)
  3. Adjust the date slider to change the date range to the time period of interest
  4. View the graph area displaying a time-series of the bloom index (extent, intensity, or severity) over the selected time interval
  5. Click on any point on the time-series to view that day’s bloom indices and 14-day average satellite-derived chlorophyll-a image
  6. Right click on the mapped chlorophyll-a product to save the image as .png
  7. Data availability legend showing the percentage of lake area covered by useable satellite data to generate imagery and indices for that date
Sample of interactive monitoring tool with instrcutions 1 to 7 identified in the appropriate sections.
Glossary of satellite-derived algal bloom indices terminology



Bloom Flag

When the chlorophyll-a concentration in a pixel is > 10 μg/L (micrograms per liter), the pixel is considered to be in bloom.

Bloom Intensity

Average chlorophyll-a concentration measured as μg/L (micrograms per liter) within the total area flagged as algal bloom

Bloom Extent

Total area of the pixels flagged as in bloom (in km2, or percentage of lake area)

Bloom Severity

Bloom Intensity x Bloom Extent (μg/L km2)

Bloom Duration

The number of days a pixel is flagged as in bloom between June and October



Data Availability (% of the lake)

The percentage of lake area covered by useable satellite data for each 14 day period. 100% indicates complete lake coverage of satellite data, and 0% indicates no satellite data coverage. Data may be unavailable due to the satellite orbit, cloud cover, or a number of quality control flags.

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