Study uses stream fish as indicators of water quality

The U.S. Environmental Protection Agency (EPA) has approved a new partnership with Virginia Tech’s College of Natural Resources to improve the way the Clean Water Act is implemented in Virginia.

The stated purpose of the Clean Water Act is “to protect the biological integrity of the Nation’s waters,” said Nathaniel “Than” Hitt, a doctoral student in the Department of Fisheries and Wildlife Sciences. “However, the law does not define what biological integrity is. That’s our task.”

For many years, regulatory agencies have used chemical standards to assess water quality. Now, researchers are discovering how biological criteria can complement chemical standards to assess the status of water bodies, including streams, rivers, lakes, and estuaries.

“Our study uses stream fish as indicators of environmental quality. Stream fish are excellent indicators because different species respond to pollution in different ways. As a result, we can assess the quality of a stream based on the diversity and abundance of fishes we find there,” said Hitt, who is working with associate professor of fisheries Paul Angermeier.

“Fishes are sensitive to forms of pollution that chemical tests may miss,” Hitt pointed out. EPA’s Office of Water has recognized this dynamic and recently provided support for Angermeier and Hitt to conduct an initial fish biomonitoring project for the Virginia Department of Environmental Quality (VDEQ). Their study will use VDEQ’s current stream biomonitoring sites within watersheds of the New and James rivers. Currently, the VDEQ uses stream insects and vegetation to assess stream quality but does not consider stream fishes except for consumption advisories due to toxins in fish flesh.

Hitt and Angermeier will investigate how fish movement from adjoining streams influences the ability of natural resources managers to detect fish responses to pollution. “Many stream fish move surprisingly long distances in streams. We need to understand these movement patterns in order to understand how fishes observed in one area indicate environmental quality in the surrounding region,” said Hitt. The researchers will use spatial analysis techniques to explore different scenarios of fish movement.