Health and Environmental Effects Research
EPA Scientists Lead International Partnership To Complete First Integrated, System-Wide Assessment of World’s Largest Freshwater Lake
Lake Superior, shared by the United States and Canada, is the world’s largest freshwater lake by area and holds more than 9% of the world’s fresh surface water. Lake Superior is so vast that conducting a full lake-wide assessment requires significant resources, such that coordinating and conducting an assessment has not been feasible for decades. ORD scientists at NHEERL’s Mid-Continent Ecology Division (MED) and Western Ecology Division (WED) have been leading development of efficient sampling designs to assess the condition of Lake Superior to demonstrate effective solutions for monitoring large aquatic systems. Based on a successful pilot assessment in 2006, MED scientists were asked to lead a multidisciplinary, multiagency, international assessment of Lake Superior in 2011, with funding from the Great Lakes Restoration Initiative. This effort was requested by the Great Lakes Binational Program, which coordinates monitoring and resource management activities pursuant to the Great Lakes Water Quality Agreement. This 2011 Coordinated Science and Monitoring Initiative was led by MED and involved active partnerships with the U.S. Geological Survey (Fisheries), EPA’s Great Lakes National Program Office/Region 5, Environment Canada, the Division of Fisheries and Oceans Canada, and several academic institutions.
The MED/WED statistically based design was comprehensive yet efficient, enabling partners, for the first time ever as a major coordinated and fully-integrated effort, to sample the entire lake, using measurements of all aspects of the ecosystem, from water quality to fish, and across all depths, from inshore to deep offshore. Sampling at 56 core stations, including water quality and chemistry, major food web biota in the water and sediments, inclusive of pelagic and benthic fish populations, was completed in September. A number of supplementary studies and measurements, involving spatially synoptic, new in situ and acoustic technologies, were fully incorporated in this effort. Overall results due within the next year are awaited eagerly by the Binational Program, which establishes Lakewide Management Plans. The assessment will be a true integrated benchmark to establish the current state of Lake Superior. It is expected to become a model for coordinated monitoring of other Great Lakes and large lakes in terms of its design and innovative technological sampling elements, as well as its use of resource agency partnerships to achieve a common vision and provide information for sound management.
This effort supports EPA’s responsibilities under the Clean Water Act and the Great Lakes Water Quality Agreement.