Research & Innovation
BGSU research team answers state call to investigate wetlands as natural solution to HAB mitigation
The key to Ohio’s future, ironically, may reside in the past – and a team of Bowling Green State University scientists is studying how slight changes in land use can benefit all Ohioans who rely upon Lake Erie.
While significant portions of northwestern Ohio’s lands are now used for agrarian purposes, the region was mostly wetlands until the late 1800s.
Now, the use of wetlands may be one of the best weapons when confronting the harmful algal blooms (HABs) that have plagued the Western Lake Erie Basin as the result of nutrients coming from the watershed.
In 2019, Gov. Mike DeWine’s office launched H2Ohio, which aimed to bring all stakeholders to the table in regard to Ohio’s water quality. The Ohio Legislature approved $172 million in funding a year later, with some of the funds earmarked specifically to understand how wetlands can be used as a resource.
The state has since allocated more than $100 million for the restoration and creation of wetlands, which are often compared to kidneys for their ability to clean water.
To study the effectiveness of wetlands in removing nutrients – in effect a protection of the state’s larger investment – BGSU scientists and students are part of a research team working with nonprofit organizations, landowners and environmental engineers to improve water quality around the state through the monitoring of these wetlands over a period of at least a decade.
The efforts of the BGSU scientists are aimed at measuring wetlands’ ability to curtail two nutrients, nitrogen and phosphorous, that are strongly correlated with HABs.
Dr. W. Robert Midden, an emeritus professor in the BGSU Department of Chemistry, said there is little doubt wetlands can help combat the HABs issue.
BGSU researchers make up three of the 11 teams working on the wetlands monitoring project: Midden helms the core water and nutrient monitoring team; McCluney and Michaels oversee the BGSU plant monitoring team; and Ganming Liu, an assistant professor in the School of Earth, Environment and Society, is in charge of hydrological modeling.
Because the water quality issue has received so much interest from so many stakeholders, scientists from many different disciplines are lending their expertise to understanding how wetlands might address the problem.
“Sometimes, the quality of the science that you can do depends on whether the stars align,” Michaels said. “Is the funding there? Are the right people there? No matter how important something is, there might be a limit.
“But in this case, the stars have really aligned.”
A simple organism and a complex problem
While Lake Erie’s algal bloom issue could likely be stopped completely by ceasing farming, that is not a realistic plan – so the state has moved forward with tweaking farming practices like fertilizer application, updating water systems and creating, restoring and studying wetlands.
The cyanobacteria that created the toxic algal bloom in 2014 are fairly simplistic.
“The bacteria are very simple critters that are photosynthetic, but they also need a few other elements, in particular phosphorous and nitrogen. Wetlands can absorb and retain phosphorous and nitrogen, so we’re trying to determine how effective the wetlands are at reducing the amount of phosphorous and nitrogen that enters the watershed.”
- Dr. W. Robert Midden
Like crops, cyanobacteria are photosynthetic, meaning they sustain themselves with sunlight, water and carbon dioxide, though they also need nutrients like nitrogen and phosphorus. Prior research has demonstrated that agricultural runoff served as the match that lit the fuse for toxic algae.
That’s where wetlands enter the picture. By slowing down, absorbing or converting agricultural runoff, wetlands can greatly diminish the nutrient explosion that fuels algal blooms.
“The bacteria are very simple critters that are photosynthetic, but they also need a few other elements, in particular phosphorous and nitrogen,” Midden said. “Wetlands can absorb and retain phosphorous and nitrogen, so we’re trying to determine how effective the wetlands are at reducing the amount of phosphorous and nitrogen that enters the watershed.”
In particular, wetlands have a propensity for turning nitrate, a key component of fertilizer, into nitrogen gas, which already makes up the majority of the Earth’s atmosphere – meaning it isn’t a problem to the ecosystem like high levels of nitrate in water.
Time, then, becomes one of the wetlands’ greatest tools: By slowing water’s rush of runoff from the farm field to the watershed, the chemical makeup of the water changes by the time it reaches its destination.
”When the water spreads out and slows down, soil particles that have eroded and are carrying some of the phosphorous and nitrogen tend to settle, so you remove the sediment, absorb the phosphate and transform the nitrogen so a lot less of both reaches destinations where they cause a problem,” Midden said. “But that takes time – you need time for that contact.”
Researchers from BGSU began formally monitoring wetlands in April and May of 2021 with about 15 wetlands projects, but more and more are being approved and completed by the month. As of now, 122 wetlands have been approved, though not all of them have been built yet.
Wetlands are slated to be monitored through at least 2031 so researchers can understand the full picture of how nutrients enter and exit wetlands, how long wetlands remain effective and which types of wetlands are most effective.
“To know what they can really do, the monitoring has to be at least that long,” McCluney said of the 10-year timeline. “Some wetlands also reach a point of saturation where they're not able to sequester nutrients, and we want to know what that point is and whether different kinds of wetlands reach that point at different speeds.”
The wetlands research is just an example of the work being done by a group of faculty and students at BGSU who focus on research related to the Great Lakes and Watershed Studies.
Meeting the moment
The scale at which plant, water and soil monitoring is being done to understand wetlands’ effect on nutrient transport can seem daunting, but the importance of the work is not lost on any of the BGSU scientists.
One of the hallmarks of the project, Michaels said, is how well researchers work together to understand how well wetlands can address the larger issue of toxic algal blooms.
“The real strength of this group is the collaboration - and not just the vegetation team, but across all the other institutions where expertise from so many different disciplines is being brought to bear on each of the areas of focus,” she said. “It’s very unique in that regard.”
Midden said the amount of collaboration involved with H2Ohio gives researchers “an unprecedented opportunity” to shed light on wetlands’ effect on phosphorous and nitrogen transport, a specific question that impacts every stakeholder who relies upon Lake Erie.
“There have been other studies that have focused on wetlands, but none that focuses on this particular question with this particular level of expertise and this particular level of resources,” Midden said. “It’s very exciting because we have the propensity to learn more about this issue than has ever been learned before.”
Updated: 02/16/2023 03:56PM