STEAMING TO THE LAKE.

• Author: Crane, Misti
• Position: EYE ON ECOLOGY - Lake Erie conservation

WHILE efforts to curtail agricultural runoff are improving the health of Lake Erie, much more work is needed to protect the streams that feed the lake, according to a study led by researchers at Ohio State University, The Nature Conservancy, Ohio Sea Grant, the Department of Agriculture, and Texas A&M University, which used computer modeling to get a handle on the impact of various conservation efforts in the western Lake Erie watershed. The area includes about 5,500,000 acres of Ohio, Michigan, and Indiana cropland, making it the most intensely farmed watershed feeding into the Great Lakes.

In light of harmful algal blooms, conservationists, scientists, and farmers are looking for ways to maintain robust agricultural production without causing damage to the surrounding ecosystem, explains Stuart Ludsin, OSU associate professor of evolution, ecology, and organismal biology and co-director of the Aquatic Ecology Laboratory.

The bulk of that work has focused on reducing phosphorous in western Lake Erie by 40%. While that is an important goal, it does not address the harms from sediment and nitrogen runoff, nor does it focus on the health of streams throughout the watershed--waters that supply drinking water, provide habitat for fish, and serve as a playground for anglers, kayakers, and others.

"Nobody has taken a hard look at how agricultural conservation practices aimed at protecting Lake Erie could influence the health of streams in the watershed," says Ludsin. "We're asking what happens to water quality and fish communities if we implement conservation measures. It's important to not just focus on the lake, but to consider the arteries that feed it. Our streams are as degraded as the lake."

The study shows that both the streams and the lake will benefit if appropriate conservation efforts are implemented, he stresses, including erosion control and nutrient management (being selective about how much fertilizer is used and when it is applied). The report contains predictions about the effects of a variety of conservation scenarios to give stakeholders information on which to base plans going forward. "Our models tell us what sort of difference it would make to streams if we reduced the amount of nutrients and sediments in agricultural runoff and leaching by 20%, 40%, or 60%."

In embarking on this work, researchers aimed to provide information that could optimize efforts to protect waters and the species that live within them from runoff...