Skip to main content
U.S. flag

An official website of the United States government

February 7, 2018

A new water-quality monitoring program, established by the U.S. Geological Survey, can provide scientists and managers with the best available data to help evaluate the health of Great Lakes ecosystems and improve water quality for recreation and commercial fishing.

Lake Erie algal bloom
Landsat satellites captured this image of Lake Erie during a harmful algal bloom event. (Credit: USGS/NASA)

As part of the monitoring program, USGS scientists collected samples and used state-of-the-art sensors to gather water-quality data for 30 major Great Lakes tributaries during 2011 through 2013. Using sophisticated scientific models to analyze the data, scientists were able to more accurately estimate the amounts, or loads, of sediment and nutrients entering the Great Lakes from tributaries than by using traditional techniques. The program is highlighted in a new USGS publication.

“The approach we developed as part of the USGS water monitoring program provides an enhanced understanding of short-term variability and long-term changes in the quality of water from tributaries,” said Dale Robertson, a USGS scientist and the lead author of the report. “Understanding inputs from these rivers is important because they can affect the environmental health of the Great Lakes.”

Scientists collected and processed water-quality information from tributaries located in a wide range of land-use settings. Water-quality information included water flow; concentrations of total phosphorus, total nitrogen and suspended sediment; and data from sensors, such as turbidity.

“Taken together, the water-quality and input information from these rivers provide a broader and more accurate picture of how water from tributaries influences the environmental health of the Great Lakes, which are a multi-billion dollar per year resource,” Robertson said.

Due to the new methodology, the annual load estimates resulting from this water-quality monitoring effort may be different from previously released estimates by the USGS and other entities, according to Jon Hortness, the USGS Great Lakes Program Coordinator. 

The USGS Great Lakes tributary monitoring program can help evaluate the overall effects of Great Lakes Restoration Initiative management efforts.

The USGS monitoring program, its new scientific modeling approach and its water-quality estimates for 2011­ through 2013 are published in the Journal of Great Lakes Research.

For more information about USGS water studies in the Great Lakes and Midwest, please visit the USGS Upper Midwest Water Science Center or the USGS Great Lakes Restoration Initiative websites.