The MPCA’s recently released report on the Lake Superior-North watershed confirms it contains some of the least-polluted water bodies in the state. However, land use practices, increasing development, and a changing climate may pose threats to these high quality resources. In the near future, MPCA, partner agencies, and stakeholders will work together to develop protection and restoration strategies for these important aquatic resources.
The watershed’s streams and rivers flow slowly through forested upland areas before plunging over steep rapids and waterfalls near Lake Superior. These high-quality water bodies support sensitive aquatic species and provide clean water for recreation and other uses. The watershed’s lakes also exhibit excellent water quality, and are enjoyed by many for fishing, boating, and other forms of aquatic recreation.
Geography and ownership shape the watershed’s development potential. More than 80 percent of its U.S. portion is under federal, state, county or municipal administration. In general, development levels are low and mostly concentrated along the Lake Superior shoreline. However, development has increased in some areas, particularly along certain lakeshores, and may be negatively affecting water quality.
Land managers, community leaders and other stakeholders should consider the best available information regarding potential stressors when developing protection and restoration strategies. Protection strategies would help support the watershed’s exceptional fish and bug communities, swimming beaches, boating and other water-contact activities. These strategies may also help prevent future impairments.
The report’s highlights include:
- High water clarity and low levels of algae indicate 94 lakes support aquatic recreation and none of the assessed lakes were impaired for this use.
- Ninety-nine lakes have fish with high levels of mercury, which is the watershed’s dominant fish tissue contaminant. Fish consumption advisories are recommended for lakes across the watershed.
- Water chemistry and the amounts and types of fish and bugs found in 63 streams indicate full support of aquatic life.
- Three streams were impaired for aquatic life due to high levels of suspended sediment. Restoration efforts are underway to address these impairments.
- Low levels of bacteria in 18 streams and 27 Lake Superior beaches indicate that these beaches support aquatic recreation.
See the full report: Lake Superior - North Watershed Monitoring and Assessment Report (wq-ws3-04010101b)
Beginning in 2013, MPCA scientists and local partners began monitoring 135 lakes, 67 streams and 27 Lake Superior beaches. Resulting water chemistry and biological data were used to determine whether these water bodies support aquatic life and recreational uses.