New Ohio Sea Grant Research Tracks Veterinary Antibiotics In Lake Erie Watersheds

New Ohio Sea Grant research measured veterinary antibiotics in Lake Erie tributaries and found that some medications are prevalent in regional watersheds at low concentrations.

“We wanted to better understand if we’re still seeing veterinary medicines in streams and rivers, how prevalent they are, and if we should be concerned about it,” said Dr. Laura Johnson, director of the National Center for Water Quality Research at Heidelberg University in Tiffin, Ohio, who led the study.

About 1.2 million kilograms of antibiotics are produced for U.S. agriculture each year, and up to 90% of those veterinary antibiotics can be excreted by livestock unmetabolized. Once in the environment, antibiotics can contribute to the phenomenon known as antibiotic resistance, in which bacteria adapt to overcome the drugs designed to eliminate them.

“If we have antibiotic resistance for bacteria that would also affect humans, that would be a problem,” said Johnson. “And if you think about it from an ecological standpoint, having more antibiotics means that you’re changing the microbial community structure of an aquatic ecosystem. That can just change how it’s functioning in general.”

To find out whether this is a concern in the western basin of Lake Erie, Johnson’s team measured pharmaceuticals at trace levels in the Sandusky and Maumee River watersheds. Researchers used passive samplers at various points across the watersheds over time, at very low concentrations. Once collected, the samples were sent to the University of Nebraska-Lincoln’s Water Science Laboratory for extraction and analysis.

Ultimately, researchers found that some antibiotics, both veterinary and human, were frequently detected in rivers and streams in the Western Basin. The team also confirmed that across watersheds, antibiotic levels were associated with the density of livestock nearby.

Johnson said that the levels of these antibiotics are relatively low — low enough that they’re likely not causing antibiotic resistance in the microbial environment of streams and rivers. However, their widespread detection could suggest that antibiotics are being applied to land at high concentrations, meaning that antibiotic resistance could still be a concern.

Results from the study will inform livestock practices in the state and regulatory bodies such as the Ohio Environmental Protection Agency and Ohio Department of Health.

“Knowing the potential for exposure to antibiotics in the environment is useful, even if the levels weren’t incredibly high,” Johnson said. “Hopefully results like this would encourage farmers and producers to not use antibiotics as often. I think anybody would agree that if there’s a sick animal or other issues, yes, use antibiotics, but use them smartly.”

About The Ohio State University :
Ohio Sea Grant is supported by The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) School of Environment and Natural Resources, Ohio State University Extension, and NOAA Sea Grant, a network of 34 Sea Grant programs nation-wide dedicated to the protection and sustainable use of marine and Great Lakes resources. Stone Laboratory is Ohio State’s island campus on Lake Erie and is the research, education, and outreach facility of Ohio Sea Grant and part of CFAES School of Environment and Natural Resources.