Minnesota's 2012 National Lakes Assessment: National, State, and Ecoregion-based Approach

2012 National Lakes Assessment (NLA) 1. Part of nation-wide random survey effort designed to assess condition of Nation's lakes, streams, wetland, & estuaries. 2. One resource type each year, surveys repeated every 5 years; 3. Statistically-based stratified random approach to allow inclusion of lakes across all size classes, all major ecoregions and all 48 states. 4. First NLA in 2007 included 1,028 lakes representing ~50,000 lakes in lower 48 states. 5. NLA 2012, 904 lakes including 450 lakes from 2007; 6. Minimum lake size was 1 ha and 1 m depth for inclusion in survey