Great Lakes Observing Systems

Aquatic ecosystems are highly dynamic.  On daily time scales fluctuations in weather conditions such as wind speed and solar radiation regulate lake currents, thermal structure, and algal photosynthesis, which in turn affects the behavior of zooplankton and fish.  On longer time scales, the functioning of lakes can be fundamentally altered by changes in climate, loading of nutrients and contaminants, and the introduction of new species.  Quantifying these changes, and distinguishing real long-term signals from background noise requires measurements made at frequent intervals over long periods of time.  While part of this need is met through ship-based sampling programs and remote sensing, continuous in-lake measurements requires the deployment of in situ sensors.

The UWM School of Freshwater Sciences maintains several observing systems on Lake Michigan, with support from the Great Lakes Observing System, the Lake Express high-speed ferry, the National Park Service, the Great Lakes Restoration Initiative, and the National Science Foundation.  These observing systems allow us to quantitatively measure long-term changes in lake hydrodynamics, thermal structure, chemistry, and biology.  The data collected by these systems not only allow us to determine how the lake is changing over time; by measuring a variety of physical, chemical and biological variables we are improving our basic understanding of how large lakes function.  In addition, these systems provide valuable support data for a variety of research projects.