IESA research uses satellites to map algae blooms
April 21, 2021
Dr. Amber Ignatius knows too much of a good thing can be bad. A prime example is the algae that grows in Lake Lanier and its tributaries in northeast Georgia.
"Algae is great at photosynthesis, which generates oxygen for the Earth and its inhabitants. Algae also provides food for fish and other organisms in the water," said the assistant professor of geography and geospatial science in the Lewis F. Rogers Institute for Environmental and Spatial Analysis at the University of North Georgia (果冻传媒).
But when algae has too many nutrients, it can develop a harmful bloom. This explosion of algae or cyanobacteria can be detrimental to wildlife, animals and humans. Cyanobacteria blooms occur in Georgia every year and happen in farm ponds, large reservoirs, and tributaries.
"When a cyanobacteria bloom occurs, it can lead to fish-kills and increased exposure to cyanotoxins," Ignatius said. "Dogs, cattle and waterfowl deaths have been directly linked to cyanobacteria exposure in the state. Symptoms in humans from exposure can include headache, fever, muscle and joint pain, stomach cramps, diarrhea, vomiting."
Ignatius said she is monitoring Lake Lanier to better understand cyanobacteria patterns in that ecosystem and to see if any high-risk locations exist in the lake.
To determine where the algae and cyanobacteria forms in Lake Lanier, Ignatius is using remote sensing technology to search through thousands of satellite images throughout an eight-year period to pinpoint the location and frequency of blooms.
"I have written code that extracts information from EPA CyAN data and thousands of satellite pictures and shows how much algae and cyanobacteria may be in the water through color variations," said Ignatius, who received a Presidential Incentive Award to conduct this research. "Thanks to Google Earth Engine and satellite images stored on the cloud, I can look at bodies of water from across Georgia and the United States."
The data Ignatius has collected and analyzed has a couple of practical applications. First, she can map out the locations of the cyanobacteria blooms and share them with the local authorities who manage the waterways.
One nonprofit that plans to be tuned into Ignatius' research is Chattahoochee Riverkeeper (CRK), which monitors algae level and water quality based on state standards at five different locations Lake Lanier.
"The same ingredients that cause elevated algae levels, like nutrient pollution and storm water runoff, are the same ingredients that cause cyanobacteria blooms as well," said Dale Caldwell, director of CRK's Headwaters office in Gainesville, Georgia. "Any information that we can learn from Amber Ignatius' type of research will help us. We can refer to it and help meet water quality standards."
A second application is the computer program can create interactive maps to see the geography and topography of the land in the past and present.
Ignatius also plans to use the data and information in an introductory science class and lab to expose students to the habitat in their surrounding area.
"We will look at Lake Lanier and investigate how scientists study it," she said. "Some scientists look at land use while others look at the historical changes in water quality over time. Students can see the broad spectrum of science while gaining a better understanding of our local area. "