EPA's Office of Research and Development initiated the Environmental Monitoring and Assessment Program (EMAP) to provide data for better assessments of the condition of the nation's ecological resources. Over the next five years, several integrated monitoring networks will be implemented to (1) estimate current status, extent, changes, and trends in indicators of ecological condition, (2) monitor indicators of pollutant exposure and habitat condition and seek associations among indicators that provide plausible explanations for adverse condition; and (3) provide periodic reports on status and trends to the EPA Administrator and the public. These networks will yield statistically unbiased estimates with quantifiable confidence limits on regional and national scales for periods of years to decades. The report presents the approach proposed to describe ecological condition; defines a common strategy within the program for selecting, prioritizing, and evaluating indicators. The report also summarizes the indicators chosen for evaluation as core indicators, which will be implemented in regional and national monitoring of six categories of resources: near-coastal waters, inland surface waters, wetlands, forests, arid lands, and agroecosystems.

"September 1990." "EPA/600/3-90/060."