May 6, 1999
Contact: Chris Curran
513-556-1806
chris.curran@uc.edu

BIOLOGISTS FIND EVIDENCE OF ATRAZINE IMPACTS IN RIVERS

Cincinnati -- An in-depth study of the ecological impact of herbicides on the Little Miami River in Ohio has turned up evidence that atrazine persists in the environment well beyond the growing season.

Alicia Shelton, a graduate student in the University of Cincinnati department of biological sciences, takes water and biological samples along the length of the Little Miami a national and state scenic River. She has been examining the levels of atrazine, because it is widely used by corn farmers. Already, Shelton noticed atrazine accumulating in the river's algae. A recent conservation award, which was matched by the biology department, will allow her to expand her studies to examine impacts on fish as well.

"I know it's bioconcentrating in algae. Those levels were really high," said Shelton. "I don't know if it will concentrate in fish."

Shelton will collect samples from the Little Miami for a full year to see how the atrazine concentrations vary from month to month. May and June are typically the months when farmers are using the herbicide, but Shelton discovered the chemical persists in the environment well into the winter months.

In her next set of samples, Shelton will study stonerollers (a type of minnow) and crayfish because they both feed on the algae in the river and because they're eaten by many of the larger fish in the Little Miami. Ultimately, the atrazine could be ingested by predatory birds and humans who eat game fish.

Shelton's adviser, Professor Michael Miller, said her research is very timely and likely to have wide applications. "Atrazine's become a problem in other surface waters too. It's very under- studied, so we don't know what it's doing." Miller said Shelton's research project will help to answer many questions about atrazine's ecological impact, because it's a full food chain study.