National Lakes Assessment 2012 Zooplankton Communities in Minnesota Lakes

The United States Environmental Protection Agency (EPA) has a responsibility to assess the health of the nation's water resources. One of the methods for assessment is statistically based surveys. The National Lakes Assessment Project (NLAP) is one of a series of water surveys being conducted by states, tribes, the EPA, and other partners. In addition to lakes, partners also study coastal waters, wadable streams, rivers, and wetlands in a revolving sequence. The purpose of these surveys is to generate statistically-valid and environmentally relevant reports on the condition of the nation's water resources at nationwide and regional scales. The sampling design for this survey is a probability-based network which provides statistically- valid estimates of the condition of all lakes with known confidence. It is designed using modern survey techniques. Sample sites are selected using a stratified-random design to represent the condition of all lakes across the nation and each region. A total of 1000 lakes in the United States were included in the 2012 Lakes Survey. The sample set is comprised of freshwater lakes, ponds, and reservoirs greater than one hectare and at least one meter in depth located in the conterminous U.S.