A University of Kentucky researcher is dedicating a significant portion of her career safeguarding a crucial component of the Earth's ecosystem. Tiffany Messer, an associate professor in the UK Martin-Gatton College of Agriculture, Food and Environment Department of Biosystems and Agricultural Engineering, is on a mission to protect pollinators and other wildlife from the hazards of neonicotinoids, an insecticide commonly used to shield crops from pests.

In a previous study published in the Journal of Environmental Quality (JEQ), Messer studied floating treatment wetlands (FTWs), engineered platforms covered in wetland vegetation that float on water bodies and naturally purify water by filtering pollutants and promoting beneficial ecological processes. She found they could help protect endangered bee populations, aquatic ecosystems and human health.

Neonicotinoid pesticides have long faced scrutiny for their impact on pollinators like bees, butterflies and other essential wildlife. Studies show these pesticides jeopardize biodiversity and taint surface water, harming aquatic creatures and human well-being. Additionally, nitrates, which are widespread surface-water pollutants, contribute to ecological disturbances.

Messer’s research suggests that floating treatment wetlands is a creative and ecologically conscious approach to combatting these issues. These engineered wetlands, designed to drift on water surfaces, are brimming with wetland vegetation that collaboratively employ physical, chemical and biological processes to purge pollutants.

In her JEQ study, Messer conducted comprehensive experiments measuring the efficacy of FTWs in cleansing surface water of neonicotinoid pesticides and nitrates. In 21 days, the outdoor experimental system showcased that FTWs successfully extracted nitrate from the water, regardless of neonicotinoid presence.

"Impressively, nitrate-N was completely eliminated by FTWs during the experiment's duration," Messer said. "FTWs removed approximately 30% of imidacloprid, a widely used neonicotinoid pesticide, and degradation byproducts. It also removed 10% of thiamethoxam, another common neonicotinoid pesticide, and degradation byproducts from the water column. Interestingly, the presence of neonicotinoids in the water didn't significantly hinder nitrate removal rates, highlighting the resilience of these systems.”

Now, Messer and her team of students are taking it a step further.

Building upon the insights from the initial study, Messer and her graduate students broadened their scope by applying their gained knowledge to various wetland designs.

“Based on our findings from the published study, we are currently studying two wetland designs that are being exposed to pesticides,” Messer said. “The first is floating treatment wetlands, often used on urban ponds to reduce algal blooms. Another is surface flow wetlands often used in agricultural settings to reduce fertilizer export to downstream environments."

Messer's team studied these designs under controlled conditions in the college’s greenhouse facilities. They aimed to understand how different pesticide and personal care product mixtures from urban and agricultural areas might affect various ecosystems.

Over two years, the researchers monitored multiple rivers across diverse landscapes in Kentucky, spanning rural Appalachia, agricultural zones, urban areas and regions influenced by mining activities. By comparing pre- and post-flood conditions, they assessed the impact of land use on river water quality. Armed with these real-world observations, the team replicated similar scenarios in their laboratory settings to examine how different pesticide and personal care product mixtures might affect wetland ecosystems.