Ohio’s investment in wetland restoration continues to show promise, according to new findings led by Lauren Kinsman-Costello, Ph.D. associate professor of biology at Kent State University. The results, published in the 2024 H2Ohio Wetland Monitoring Program Annual Report, offer valuable insights into how wetland design and management influence nutrient retention — information that is already helping guide statewide strategies to improve water quality and reduce harmful algal blooms (HABs) in Lake Erie and beyond.
Since 2021, scientists from Kent State and five other universities — working through the Lake Erie and Aquatic Research Network (LEARN) — have been tracking 45 wetland restoration, enhancement, and construction projects across the state. The long-term monitoring effort evaluates how these wetlands capture and store phosphorus and nitrogen, nutrients that can contribute to HABs when they reach rivers and lakes.
“This report improves our understanding of how to design and manage wetlands for maximum environmental benefit to help reduce HABs,” said Kinsman-Costello, who leads the H2Ohio Wetland Monitoring Program. “The findings help ensure that every dollar invested in these projects delivers the greatest return in cleaner water and healthier ecosystems.”
Proof That Restoration Is Working
The research confirms that wetlands consistently retain nutrients, though their performance varies depending on design, landscape, and weather. Across the monitored sites, wetlands retained between 0.2 and 29 pounds of phosphorus per acre and up to 863 pounds of nitrogen per acre. Phosphorus retention is a key focus, since it is the primary driver of Lake Erie’s algal blooms.
Wetlands that drained large, nutrient-rich watersheds and held water for longer periods performed best. Sites with active management features such as control structures or pumps captured more nutrients than passive systems, and native vegetation contributed to both biodiversity and nutrient cycling.
Drought conditions in 2024 meant less nutrient inflow than usual, providing what Kinsman-Costello described as a conservative baseline for future comparisons. “In wetter years, we expect these wetlands to intercept even larger nutrient loads,” she said.
Science Shaping Policy
The monitoring program, part of Governor Mike DeWine’s H2Ohio Initiative and managed by the Ohio Department of Natural Resources, is designed to ensure that restoration projects are guided by measurable data. Findings from Kent State and its LEARN partners are helping planners refine wetland placement and management to achieve the greatest impact for Ohio’s waterways.
For more on Kinsman-Costello’s earlier research and background on Ohio’s wetland monitoring efforts, visit this 2024 story:
“Kinsman-Costello Gives Update on Ohio’s Wetland Restoration Efforts and Impact on Lake Erie.”
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Media Contacts:
Lauren Kinsman-Costello, Ph.D., lkinsman@kent.edu, 330-672-3640
Jim Maxwell, JMAXWEL2@kent.edu, 330-672-8028