How Satellite Data Led to A Breakthrough for Lake Erie Toxic Algal Blooms

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With the growing frequency and magnitude of toxic freshwater algal blooms becoming an increasingly worrisome public health concern, Carnegie scientists Jeff Ho and Anna Michalak, along with colleagues, have made new advances in understanding the drivers behind Lake Erie blooms and their implications for lake restoration. The work is published in two related studies.

Using data from NASA’s Landsat 5 instrument, the researchers generated new estimates of historical algal blooms in Lake Erie, more than doubling the number of years previously available for scientists to investigate, from 14 to 32. (This first study was published in Remote Sensing of Environment.) Exploring this new historical record, they discovered that decadal-scale cumulative phosphorous loading—that is the runoff that enters the waterway—helps to predict bloom size in addition to the effects from same-year phosphorus inputs. The work suggests that it may take up to a decade to reap the benefits of recently proposed nutrient loading reductions. (This second study was published in the Journal of Great Lakes Research.)

With the growing frequency and magnitude of toxic freshwater algal blooms becoming an increasingly worrisome public health concern, Carnegie scientists Jeff Ho and Anna Michalak, along with colleagues, have made new advances in understanding the drivers behind Lake Erie blooms and their implications for lake restoration. The work is published in two related studies.

Using data from NASA’s Landsat 5 instrument, the researchers generated new estimates of historical algal blooms in Lake Erie, more than doubling the number of years previously available for scientists to investigate, from 14 to 32. (This first study was published in Remote Sensing of Environment.) Exploring this new historical record, they discovered that decadal-scale cumulative phosphorous loading—that is the runoff that enters the waterway—helps to predict bloom size in addition to the effects from same-year phosphorus inputs. The work suggests that it may take up to a decade to reap the benefits of recently proposed nutrient loading reductions. (This second study was published in the Journal of Great Lakes Research.)

Harmful freshwater algal blooms result when excessive amounts of phosphorus are added to the water, often as runoff from fertilizer. The excess phosphorus stimulates the growth of aquatic plants and phytoplankton like the blue-green algae Microcytsis sp., an organism that produces a toxin affecting the human liver and can also cause skin irritation.

Continue reading at Carnegie Institution for Science

Image: The left image shows the record-setting lake algal bloom in 2015 from space, while the right shows a 2009 bloom on the southeast shore of Pelee Island, Ontario.  (Credit: Images courtesy NASA MODIS and Tom Archer)