The Dead Zone Revisited: A University of Michigan professor and his students work to solve the problem of hypoxia in Lake Erie

Don Scavia

A few weeks ago I wrote about the "dead zone", or hypoxia region, that forms in Lake Erie's central basin as a result of the presence of excessive nutrients in the lake, causing too much algae to grow and, in turn, consume precious oxygen in the water needed to sustain indigenous fish and plant life. It's such a serious problem, one that threatens Lake Erie's fragile ecosystem.

One of the guys on the front lines working to find solutions to this problem, Don Scavia, Professor of Natural Resources and Environment and of Civil and Environmental Engineering at the University of Michigan in Ann Arbor. Don and his students combine numerical models, laboratory and field work, and assessments to improve the understanding of interactions between human activities on land and their impacts on coastal marine and freshwater ecosystems. Don has also served on the Boards of Directors for the American Society of Limnology and Oceanography, the International Association for Great Lakes Research, and the Great Lakes Observing System.

In testimony before the Subcommittee on Energy and Environment Committee on Science and Technology in September of 2009, Dr. Scavia call hypoxia "an issue of global importance." He told the subcommittee that "the dead zone in Lake Erie, once thought to be under control and shrinking, has grown again to sizes not seen in decades." He went on to say:

Clearly, the nutrient pollution problem is not under control, and if more is not done to reduce this pollution to coastal and Great Lakes waters, we can expect further degradation and loss of important recreational and commercial resources.

In a recent article in the Great Lakes Echo, Dr. Scavia is attributed as saying that the dead zone in the central basin of the lake has grown up to two thirds of the entire lake in recent years. While cropland area has not substantially increased since the 1950s, agriculture intensification has brought loss of natural habitats and increased use of pesticides, fertilizer and manure which pollute the lakes. These factors, combined with heavy spring and fall precipitation, are thought to be the cause the increased hypoxia in the lake.

Dr. Scavia is currently heading up a study to establish the link between climate change, farming and dead zones, with the ultimate goal of helping farmers modify their practices to control their impacts on the lakes. One avenue to help lessen the impact, according to Scavia, would be amending the Farm Bill, a federal law that regulates agricultural practices, so that it allocates more funds and works towards land and water conservation.

Tell your representatives to fight for these changes in the Farm Bill and other measures that will help save Lake Erie.

In a balanced ecosystem (left) some nutrients fuel the growth of microscopic algae, which are the base of the aquatic food chain. In an unbalanced ecosystem (right), excess nutrients cause too many algae to grow. The excess algae die, sink to the bottom, and are decomposed by bacteria, which use up oxygen in the water. Image: google.com