Algae blooms have been a problem in Lake Erie for decades. But scientists are still working on understanding all of the factors that cause them, and the best ways to fix the issue.
Researchers and leaders in both the Ohio Department of Agriculture and Environmental Protection Agency discussed updates on harmful algal bloom research, and water quality programs in the state at the Understanding Algal Blooms: State of the Science virtual conference Sept. 8.
A lot of it comes back to nutrient runoff from farmland, especially phosphorus. But reducing runoff is complicated, especially with climate change contributing to more rain and extreme storms in the Midwest.
“Controlling phosphorus, it’s sources, pathways, and considering its trade-offs is seriously complicated. It’s also very site specific,” said Deanna Osmond, extension leader in soil fertility and watershed management at NC State University.
Nutrient runoff from farmland in the Maumee Watershed is a major contributor to harmful algal blooms in the lake. There are three types of best management practices for reducing nutrient runoff from farmland.
They include practices that prevent phosphorus loss through nutrient management, so farmers don’t over-apply fertilizer, practices that control phosphorus as it moves through the field with things like cover crops and conservation tillage and practices that trap phosphorus, like wetlands and riparian buffers, Osmond said.
But practices that are beneficial in some ways might also cause issues in other ways, she said. For example, a practice that reduces dissolved phosphorus runoff might turn out to increase particulate phosphorus runoff.
When choosing conservation practices, she encouraged people to identify what pollutant they are concerned about, match practices to the pollutant and to the way water moves in that area, consider the trade-off effects, identify sources of the pollutant in the area and work with farmers to understand the economic and sociological effects of the practices.
Osmond also encouraged people to talk to researchers in their own state who are working on conservation practices. Different practices work in different places, since landscapes, soil types and other factors can impact how effective a particular practice is.
Phosphorus isn’t the only thing that plays a part in harmful algal blooms. Researchers said warmer temperatures also make Lake Erie friendlier to algal blooms. And nitrogen runoff seems to be connected to more toxic algae, said Silvia Newell, of Wright State University.
Researchers have been working on methods for forecasting the toxicity of algae blooms, but don’t yet have a reliable method for doing that long-term.
With the lake getting warmer and extreme storms that increase runoff becoming more common, farmers may need to reduce nitrogen and phosphorus inputs even more, said Hans Paerl, of the Institute of Marine Sciences at University of North Carolina at Chapel Hill.
The Ohio Environmental Protection Agency is continuing to work on developing a total maximum daily load, or, TMDL, for the Maumee Watershed. States are required to develop TMDLs for watersheds that do not meet water quality goals under the federal Clean Water Act.
The Ohio EPA released a draft of a loading analysis plan for public comment Sept. 8. The plan lists specific sites that are impaired — for example, shorelines that are impaired for aquatic life or surface water that is impaired for public drinking water. It also covers how water quality restoration targets are set to directly address those impairments, and proposes a method for calculating a TMDL, said Tiffani Kavalec, chief of the division of surface water at the Ohio EPA.
That draft is open for public comment until Oct. 8. The Ohio EPA will have a virtual event Oct. 5, at 2 p.m., to go over the plan and answer questions about it. The final TMDL report is planned to be completed and approved by the U.S. EPA by the end of 2022.
The Ohio EPA has also approved 47 nine-element plans — watershed plans that meet U.S. EPA standards — and is accepting more proposals for projects that fit within those nine-element plans through Oct. 18.
The H2Ohio program is wrapping up extending contracts for farmers in the first 14 counties, who originally signed up for one-year contracts, before funding was certain. It is also rolling out the program in an addition 10 counties. This roll out, however, is a little different than the first one.
For the first round of sign ups, in the Maumee Watershed, it was more of a “shotgun start,” said Terry Mescher, coordinator for the Ohio Department of Agriculture’s H2Ohio Western Lake Erie Basin Program. Farmers were developing voluntary nutrient management plans, and signing up for other best management practices at the same time.
For the new 10 counties, farmers can submit voluntary nutrient management plans until Oct. 15, or sign one-year contracts for a limited list of practices — nutrient management plans, conservation crop rotations with small grains or overwintering cover crops — through Sept. 15.
Next spring, those 10 counties will have another sign up period for three-year contracts, with all of the current H2Ohio practices for the watershed accepted.
It’s hard to say how much more funding will be needed if H2Ohio keeps expanding, but on average, the program commits about $40 per acre. With the initial rollout, the goal was to get as many acres enrolled as possible, Mescher said. Going forward, the program may be a little choosier about which acres it brings in, focusing on land that has the most potential for the most impact.
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