To Boost Health of Great Lakes, Study Focuses on Circulation Patterns

BUFFALO, N.Y. -- If the Great Lakes behaved like gigantic mixing bowls, then water, sediments and pollutants would be distributed evenly and even large concentrations of pollutants would turn up only in tiny concentrations.

Unfortunately, different regions of each of the Great Lakes have different circulation patterns, with some of them tending to concentrate pollutants, algae and other harmful organisms right along the shoreline, exactly where people and communities tend to interact with them.

With funding from New York Sea Grant, a researcher with the University at Buffalo's Great Lakes Program and his colleagues at the Environmental Protection Agency and the National Oceanic and Atmospheric Administration are studying how flow patterns impact the health of lakes Erie and Ontario.

They will use the two-year, $136,000 grant to develop a set of tools to calculate average conditions in lakes Erie and Ontario during different seasons of the year, in order to better understand the relationship between physical forces in the lakes and their biological resources.

The ultimate goal is improving the health of the lakes' ecosystems, said Joseph F. Atkinson, Ph.D., UB professor of civil, structural and environmental engineering and principal investigator for the project. Atkinson also is director of the Great Lakes Program in the UB School of Engineering and Applied Sciences.

"Generally, the lakes are in good shape with a couple of reservations," he said, noting that there are still fish-eating advisories for all of the Great Lakes.

"One of the key management issues that researchers are working toward is to eventually make Great Lakes fish safe to eat," he said.

Under the grant, Atkinson is conducting hydrodynamic calculations, three dimensional calculations that describe the motion of water in lakes Erie and Ontario to discover the physics of how water moves around the lakes.

"If you go out into the middle of the central basin of Lake Erie, not much movement is happening out there," said Atkinson. "In both lakes Erie and Ontario, the flow patterns are much stronger along their southern coasts."

Those flow patterns determine in large part how fish and other organisms obtain nutrients, which populations of organisms will flourish or decline, and where runoff and pollutants will have the biggest impact.

"Suppose a quantity of pollutants were dumped into the Detroit River and they flowed into Lake Erie," Atkinson said. "If the lake were just like one big reactor so that the pollutants were mixing with the whole volume of the lake, then you'd get exceedingly small concentrations of those pollutants at any one point. But because Lake Erie has a shoreline flow, where it tends to move along its southern coast, these regions of the lake will have much higher concentrations of pollutants than an area in its central basin."

A similar flow can be seen in Lake Ontario when pollutants are dumped into the Niagara River.

Atkinson and his colleagues will focus on watersheds and resource sheds.

Whereas watersheds are fixed geographic entities, resource sheds can shift as winds change, pushing resources, such as organisms, nutrients and sediments from one area of the lake to another, Atkinson explained.

"Conditions like wind speed and direction, as well as temperature, variables that will be influenced by global warming, will change circulation patterns in the lakes over time," said Atkinson.

The other researchers on the grant are David F. Raikow, research aquatic ecologist with the U.S. Environmental Protection Agency and Thomas E. Croley II, research hydrologist with NOAA's Great Lakes Environmental Research Laboratory.

The Great Lakes Program at UB was established in 1985 to support efforts designed to protect and preserve the Great Lakes ecosystem. This ecologically and economically important ecosystem is home to more than 40 million people in the United States and Canada.

The University at Buffalo is a premier research-intensive public university, the largest and most comprehensive campus in the State University of New York. Recognized among American colleges and universities for its leadership in reducing energy costs through extensive and innovative conservation measures and in promoting alternative energy sources, UB this semester is celebrating its environmental commitment under the theme "A Greener Shade of Blue."

New York Sea Grant is a cooperative program of the State University of New York, Cornell University and NOAA. Its statewide network of integrated research, education and extension promotes the wise use and protection of marine and Great Lakes resources.