Environmental Monitoring & Assessment Program

Thomas E. Dahl

U.S. Fish and Wildlife Service, Onalaska, Wisconsin

The U.S. Fish and Wildlife Service (USFWS) is the principal Federal agency that provides information to the public on the extent and status of the Nations wetlands. The goal of Wetlands Status and Trends Study is to produce comprehensive, statistically valid acreage estimates of wetland resources in the United States.

The U.S. Environmental Protection Agency (USEPA) anticipates conducting a probabilistic national survey of wetland condition in 2011. This survey will be one in a series of National Water Quality Assessments carried out by USEPA to provide a better understanding of the condition of the nation’s waterways.

USEPA and FWS are working in close collaboration to ensure the national condition assessment effectively compliments the existing Wetlands Status and Trends Study. While USFWS documents trends in wetland acreage, the National Wetland Condition Assessmentwill evaluate the ambient health of the nation’s wetland resources.

USEPA is beginning to examine the key survey design issues and research a number of options through regional pilot projects and inter-agency work groups. Through these preliminary efforts, it is clear that the USFWS wetland trend plots offer a potential means to define the target population and establish a tier 1 sample frame for the probabilistic national condition survey.

USFWS plot data were developed using a standardized, consistent approach that has been field tested and is well documented. They provide more contemporary spatial wetlands data, and the highest probability of a given point actually is a wetland. USFWS and USEPA continue to explore sampling augmentation, plot distribution and implementation strategies.

Keywords: wetland trends, wetland condition, monitoring, statistical sampling, sample design