The 48 aquatic landscape features (see table below) were based on an existing stream classification for Michigan (Seelbach et al. 1997), general wetland types (USEPA 2005a), lake features (Wetzel 2001, Kalff 2002), and other landscape components or characteristics identified through scientific literature review as important to a significant number of aquatic SGCN. Location/distribution maps of aquatic landscape features were generated using spatial data from several sources, including the DNR (Seelbach et al. 1997, Breck 2004, DNR 2004a, DNR 2005a), Detroit Zoological Institute (2005), Environmental Systems Research Institute (ESRI 2000), MNFI (2005), the National Ocean and Atmospheric Association (NOAA 2004), The Nature Conservancy (TNC; DePhilip 2001), the University of Michigan (2005), USFWS (USFWS 2005) and the U.S. Geological Survey (USGS 2005a). The maps are included in the Landscape Feature Summaries.