Data for Discovery and Decision-Making: LakeSuperiorStreams.org

Abstract

An estimated 720 perennial and 127 intermittent streams flow into L. Superior, including 309 trout streams and their tributaries (>2100 miles) along the North Shore and St. Louis River Estuary alone. Bedrock escarpments create a high density of stream corridors in forested watersheds with steep gradients, thin erodible soils, typically low productivity, and “flashy” hydrology. These high-quality trout streams are sensitive to urbanization and rural development by factors raising water temperature and increasing water and sediment runoff, e.g. openings in riparian cover/canopy, impervious surfaces, road crossings, construction runoff, and the warming and increased frequency of severe storms predicted by climate change models (Wuebbles & Hayhoe 2003). Tributary streams are increasingly threatened by development as urbanization and rural development place increased pressure on the Lake Superior region’s coastal communities. Between 1992 and 2001, a 33% increase in low-intensity development occurred within the basin with an alarming transition from agricultural lands to urban/suburban sprawl (Wolter et al. 2007). In the early 1990s, over 50 new lodging establishments were constructed along the Superior North Shore, and from 1990-1996 Cook County, MN experienced a 24% population increase (MPCA 2000). Stream fish, amphibians, and the invertebrates that sustain them are being adversely impacted by increased temperature, excessive peak flows, turbidity and suspended solids, road salts, organic matter, and nutrients from increased development (Anderson et al. 2003). This conclusion is supported by the fact that 11 of 27 major Minnesota North Shore trout streams have been listed as Impaired (2010) since the 1990s and remain on the State 303(d) list - primarily for turbidity, temperature, and fish tissue-Hg. The integrity of these watersheds is also critical to the condition of the coastal and offshore waters of Lake Superior. The streams discharge directly into the nutrient and sediment sensitive coastal zone of ultra-oligotrophic L. Superior, or indirectly into the lake via the St. Louis River Estuary, itself an IJC designated Area of Concern and a zero discharge (of persistent organic pollutants (IJC 1999; MPCA 2000), in part because of its levels of phosphorus and suspended sediment. This is particularly important because the lake’s nearshore zone is the source of much of its biological productivity and recreational use, but is nutrient deficient and therefore, very sensitive to excess inputs of nutrients, suspended solids, turbidity and organic matter (e.g. Sterner et al. 2004; Rose and Axler 1998). Therefore, despite the fact that Lake Superior and its tributaries are among the most pristine waters in Minnesota and in the entire Great Lakes Basin, some of these resources are already stressed by increased urbanization and tourism. This creates the unusual challenge of how to inform the public, businesses, and local units of government (LGUs) that these resources need protection when few problems are obvious to the untrained eye. This project has built on the foundation established by the award-winning project www.LakeSuperiorStreams.org (LSS) that was created in 2002 via an EPA grant to a Partnership of the City of Duluth Stormwater Utility, the University of Minnesota –Duluth (Natural Resources Research Institute, Minnesota Sea Grant, and Department of Education), the Minnesota Pollution Control Agency (Duluth Office), the Western Lake Superior Sanitary District, the Great Lakes Aquarium, and the Lake Superior Zoo (Axler et al. 2006, 2003; Lonsdale et al. 2006). The original partnership has remained substantially intact since 2002. The ultimate goal continues to be to improve environmental decision-making by: (1) Enhancing public understanding of the connections between weather, hydrology, land use and the condition of water resources in urban and rural watersheds, and (2) Providing easy access to tools for accomplishing the protection of un-impaired resource and cost-effective restoration of degraded sites.