New device will help Madison address algae problem

Every year, blue-green algae blossoms on Madison’s waterways, contributing to beach closings and public health concerns. A research team from UW-Madison and UW-Milwaukee will soon have a new tool to address the problem.

Researchers are nearing completion on a device that autonomously collects water samples and preserves the biological material for later testing. The device will make it easier to study water quality issues such as cyanobacteria – often referred to as blue-green algae blooms – which are difficult to anticipate, said Katherine McMahon, associate professor of both bacteriology and civil and environmental engineering at UW-Madison.

She noted that since cyanobacteria grows and dies so quickly, it’s hard to know when to collect samples.

“A lot of people are…calling out for this sort of technology, because it’s really expensive to send people into the field that routinely,” said Matthew Smith, leader of the research team and assistant professor in the School of Freshwater Sciences at UW-Milwaukee. The team also includes Madison Ph.D. candidate Lucas Beversdorf.

Wisconsin’s lakes have problems with cyanobacteria largely because of phosphorus runoff from streets and farms. This has been difficult to manage, since runoff is hard to control and traditional filtering methods are expensive and relatively ineffective. Despite the biological material’s prevalence, its short life-cycle makes studying it a daunting task.

That’s where the device, called the Sample Filtration and Archival (SaFA) device, will help: researchers will be able to install it in a body of water, program it to collect samples on a certain schedule, and then go out and collect all of the samples at once.

McMahon emphasized the SaFA device’s ability to preserve the sample material. If they didn’t include the chemical reaction that stabilizes the samples, the samples would change before researchers could collect them.

But with that preservation, researchers will be able to install a device in Lake Mendota, for example, to take two or three samples a day and then collect them at the end of each week. McMahon expects to eventually install two or three of the devices around Lake Mendota.

This enhanced sample collection will help them better understand how the toxic and non-toxic species of cyanobacteria come and go, McMahon said. They will also be able to study the role of nitrogen, which could help them predict what kind of cyanobacteria will show up based on nitrogen concentration.

Smith said the device costs around $10,000 to build, but that all of the plans and software for it will be available for other researchers to download under an open source agreement. He and the research team tried to use as many easily accessible components as possible, he said, though there are some that researchers will have to make themselves. 

“The idea of making the system open source was to not only answer my specific research questions as far as microbial ecology goes but to helping [other] people answer theirs,” Smith said.

While the SaFA device is limited to collecting and storing samples to be tested later, the team plans to develop a second generation device capable of testing the biological material it traps. This could greatly improve public health authorities’ ability to give early warnings for beach closings because of faster test results.

“It will allow us to have a much better sense of when it’s safe to go in the lake and when not,” said McMahon. “I think right now it’s a bit arbitrary, because the beach closings are mostly based on a lifeguard looking out over the water and trying to decide if it looks a little bluish or not.”

But the second generation device will probably not be developed for at least another five years, McMahon said. In the meantime, Smith expects the current SaFA device to be ready for field testing around November.

Their research received funding from both the Sea Grant Institute and the National Science Foundation (NSF), though the NSF funds are ongoing.

Water quality and harmful algae blooms are an important issue, especially around Madison, McMahon said, explaining her desire to work on the project.

“I think it’s a nice research topic because it’s very important locally, it resonates well with people,” she said. “It’s an important problem that needs to be solved.”