National Lakes Assessment Analysis of Physical Habitat Condition Indices (PHab) for Minnesota Lakes

The complexity and extent of near-shore and upland riparian natural vegetation, woody debris and substrates influence the richness of aquatic and terrestrial animal communities (e.g., Sass et al. 2006; Smokorowski and Pratt 2007). These same areas tend to be the focus of residential and sometimes commercial development in Minnesota and elsewhere as humans are drawn by the aesthetic and/or recreational value of lakes. Vegetation, wood, and bottom substrates (collectively considered physical habitat for fish and wildlife) are directly impacted by human development activity along shorelines (Beck et al. 2013; Borman 2007; Christensen et al. 1996; Marburg et al. 2006; Ness 2006; Radomski 2006). Development activities may cause the removal of physical habitat, for example, by clearing terrestrial vegetation to prepare a building site and lawn or by removing rocks, aquatic plants and wood from shallow, nearshore areas to reduce interference with boating and swimming. Secondary activities associated with development further affect habitats, for example, aquatic plant and bottom substrate disturbance related to boating in shallow water. Physical habitat disturbances consequently have measurable impacts on the biological community around lakes (e.g., Garrison et al. 2005; Lindsay et al. 2002; Radomski and Goeman 2001; Woodford and Meyer 2003). Impacts to biological communities may affect population size structure, species composition or representativeness, the number of individuals present, or various combinations of these responses.