On Monday, President Obama signed bipartisan legislation to increase the federal focus on the harmful algal blooms plaguing the Great Lakes and U.S. ocean waters. But progress in understanding HABs is already underway, thanks to an ongoing collaboration between two federal agencies.
Researchers from NASA and NOAA have been working together to improve monitoring of HABs, which pose significant threats to humans and wildlife as they form, spread, and disappear. Specifically, HABs often contain microcystin, which has been linked to serious liver damage, some forms of cancer, and skin irritation. The toxin also can cause mass deaths of fish and harm those who consume them as well as kill dogs swimming in infected water.
Early HAB detection allows public health officials to prevent contaminated drinking water and fish to enter the market as well as to close lakeshore recreational areas. Since the Great Lakes provide drinking water for 40 million people and more than 500 beaches, this is a vital issue.
Finding a “Fingerprint”
The experts who have been tackling the HAB issue are based at NASA’s Glenn Research Center in Cleveland and NOAA’s Great Lakes Environmental Research Laboratory in Ann Arbor. Their goal is to use remote sensing techniques — rather than time-consuming and expensive water sampling — to detect the early formation of a HAB, distinguishing it from a regular, non-harmful algal bloom.
To achieve this goal, the team wanted to identify microcystin’s unique hyperspectral signature — essentially a visual fingerprint.
Their work has been a true collaborative effort:
- NASA provided the optics researchers that developed an innovative hyperspectral imager for aerial observations of the lakes as well as the aircraft, coordinating with other research flights for efficient use of research dollars and flight personnel time.
- NOAA contributed its in-depth understanding of the Great Lakes’ biological processes and its water vessel fleet and experience with collecting water samples concurrently with NASA’s flights.
The researcher team analyzed the air- and water-based data to develop a critical algorithm for detecting microcystin. In calibrating the results, they confirmed the unique hyperspectral signature for HABs. This “fingerprint” allows scientists to identify HAB formation early and reliably through remote sensing.
Field testing will continue, with two flights over Lake Erie. The greater store of data on the Great Lakes provided by these flights eventually may help researchers understand not only when but why HAB events are occurring.