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New Targeting Strategies to Fight Algal Blooms

July 30, 2024

Tom Zimnicki headshot.
Tom Zimnicki, Agriculture & Restoration Policy Director

This August marks the 10-year anniversary of when residents of Toledo, Ohio awoke to urgent warnings not to drink or use their tap water. Half a million people were unable to drink their water, cook with it, or brush their teeth. The cause? Toxins from a harmful algal bloom growing in Lake Erie.

Fueled by nutrient pollution, largely from agriculture, and exacerbated by climate change, toxic algal blooms are a growing threat across America. Chronic blooms persist on Lake Erie and are now appearing on all Great Lakes – which contain 22% of the world’s supply of fresh surface water.

What can be done to stop the spread of toxic algal blooms?

One approach has been to spend government funds at both the state and federal levels on farm-level conservation practices. These initiatives aim to stem the deluge of nitrogen and phosphorous – the two main components of farm fertilizer that fuel blooms – from entering the lakes.

Despite years of work and hundreds of millions in taxpayer funds spent, that approach has largely failed. In 2015, the governors of Michigan and Ohio pledged to reduce phosphorus runoff to Lake Erie by 40% in ten years. It is widely understood by all parties with an interest in cleaning up algal blooms that we will not meet those reduction targets by a wide margin. Alliance for the Great Lakes research shows that farm conservation measures in Ohio and Michigan are woefully underfunded and that despite years of investment, adoption rates of conservation practices are still far behind where they need to be. The current approach – inadequate funding and not enough farms following best practices – is failing to protect our water.

Given the magnitude of the problem and the inadequate funding, states must prioritize and target funding to the highest priority fields and the most cost-efficient practices. In partnership with the engineers and scientists at LimnoTech, and with guidance from Michigan’s Department of Agriculture and Rural Development and Department of Environment, Great Lakes, and Energy, we’ve developed tools aimed at improving our ability to reduce phosphorus loads from five priority subwatersheds feeding Lake Erie and ultimately Michigan’s entire portion of the Western Lake Erie Basin.

Over the past two years, we developed a two-pronged approach to aid in nutrient reduction planning in Michigan. First, we created maps that help identify possible priority fields for conservation implementation based on field characteristics in a subset of Michigan’s portion of the Western Lake Erie Basin. These maps are not intended to definitively identify fields that are losing phosphorus. Their utility exists as a starting point for outreach efforts to the agriculture community. Second, the report lays out a methodology and rationale for targeting efforts in one area over another.

Traditionally, state and federal agencies have funded conservation implementation without prioritizing locations. By identifying fields that are most at risk of losing phosphorus, and by giving the state and agencies tools to prioritize outreach efforts, we aim to make a bigger impact using the limited funds available. Our analysis also identifies the cost and acres of conservation practices necessary to meet the phosphorus targets that Michigan and Ohio agreed to in 2015.

Understanding current water quality in the subwatersheds of the Western Lake Erie Basin is critical for making informed decisions on future conservation spending. Earlier this year the Alliance, in partnership with LimnoTech and Michigan State University’s Institute of Water Research, launched a five-year water quality monitoring effort in the headwaters of the Western Lake Erie Basin. This monitoring is funded through the Department of Agriculture and Rural Development ($4.86M) and the Fred A. and Barbara M. Erb Family Foundation ($600,000). The investment from the Department is its largest in water quality monitoring. Sensors will be deployed that will measure nutrient pollution in real time, and the results of this monitoring can be used to further understand where interventions can have the biggest impact in keeping water clean. While this work is focused in Michigan, we believe the methodology is transferable throughout the Great Lakes region.

We hope that state agencies can use this information to better prioritize how they spend their limited time and money. If an agency can start moving towards a more targeted approach to spending money, more of our water will be protected and states will move closer to meeting their existing commitments.

Downstream Water Users Bear Financial Burden of Upstream Pollution

Ohioans across the state are struggling to afford their water and sewer bills. Our 2022 study shows that water bills are pushed even higher for communities that pull their drinking water from Lake Erie due to harmful algal blooms caused by upstream agricultural pollution.

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