Aquatic Ecology Monitoring and Assessment (EMAP)
The following information is from the draft Region 8 Surface Waters
Plan for EMAP (U.S. EPA, 2000). The Environmental Monitoring and
Assessment Program was developed in EPA's Office of Research and
Development (ORD) to monitor status and trends in the condition of the
nation's aquatic ecological resources at regional and national scales.
The EMAP Western Pilot (Western EMAP) is a five-year effort (1999-2003)
by EPA Regions 8, 9, and 10 in partnership with States, Tribes and other
parties to advance the science of aquatic ecosystem health monitoring
and to demonstrate the applicability and usefulness of EMAP indicators
in environmental assessments. Western EMAP is intended to demonstrate
the value of monitoring based on a randomized design in the western
United States by applying these techniques to assessment questions of
regional and state interest.
EMAP sample sites are selected with a stratified randomized design that
uses the EPA River Reach File (RF3) as the hydrographic base layer
("the sampling frame"). EMAP uses a statistical sampling
design based on a systematic grid, which provides uniform spatial
coverage and ensures that each ecological resource is sampled in
proportion to its geographical presence. There will be at least 50
stream sites sampled in each western state over a 5-year period,
providing 12 independent state reporting units. The design will also
permit the combination of results into a Regional and West-wide
assessment of flowing waters (rivers and streams), or to divide the West
into other assessment units (e.g., ecoregions, river basins,
etc.), providing there are a sufficient number of sites in these units.
Comprehensive assessments resulting from the Western EMAP will serve as
a baseline against which future assessments can be compared in order to
reveal improvements in biological conditions resulting from regulation
and restoration efforts.
Previous EMAP efforts have revealed that error rates within RF3 can be
very high, including errors of inclusion (where digital maps show a
stream trace, but no stream actually exists, a common error in arid
areas), and errors of exclusion (where more streams exist than are
mapped). One of the goals of Western EMAP is to make accurate estimates
of these error rates for the western U.S. This is important because RF3
is the common sample frame used by States and EPA's Office of Water to
estimate the number of miles of streams in a state.
The base sampling design will allow comparisons to be made across Region
8 (Colorado, Montana, Wyoming, South Dakota, North Dakota, Utah) and
across EPA Regions 8, 9 and 10. This will be accomplished by allocating
approximately 50 sites per State (Table 1) over a four-year sampling
period (beginning in the year 2000). Because randomly selected sites may
have problems for a variety of reasons (e.g., site access, safety, RF3
errors, impoundment), the initial design will over-select sites to
ensure that a sufficient number of target sites are chosen.
Table 1. Expected sample sizes by state for base EMAP,
the Upper Missouri River Basin Focus Area, including Regional
EMAP (REMAP) sites.
EMAP (Overlay with Focus area and REMAP)
Glaciated plains REMAP
CO Plateau REMAP
area plus REMAP overlap
discounted for overlap with base EMAP
View maps depicting proposed sampling locations in Wyoming.
The second relevant scale, the focus area, is based on the desire of
Region 8 to better characterize the ecological conditions of aquatic
resources in the Upper Missouri River Basin. This focus area will be
sampled over the same four-year period as the base sample sites.
Resources to be examined within the Upper Missouri River Basin focus
area include streams, large rivers, mainstem Missouri River Reservoirs
and riverine wetlands. For streams and rivers (excluding the mainstem
Missouri River), about 275 sites will be sampled within the Upper
Missouri River Basin.
In Region 8, the surface water program will be integrated with
Western EMAP's landscape characterization program. The objectives of
this integrated effort are to quantify and validate watershed-level
indicators of ecological condition, identify areas contributing the most
to nonpoint source pollution, and to identify factors contributing to
water quality impairment and stream habitat degradation (e.g., through
correlative analyses with landscape indicators).
Biotic assemblages and their physical and chemical habitat vary among
seasons and among years at each site. To minimize the effect of temporal
variation at each site, samples will be collected during a restricted
"index" period. Index periods are selected based on logistical
(safety, accessibility to sites) and biological criteria (development of
biotic assemblages). While short index periods of a few weeks may be
ecologically optimal, logistic considerations make a longer index period
preferable. For the past and ongoing REMAP projects in Region 8, the
index period is in late summer and early fall.
The Corvallis Laboratory of EPA's Western Ecology Division (WED) will
have primary responsibility for data management for Western EMAP. WED
will provide standardized field data sheets. The field data sheets will
be returned to Corvallis where they will be optically scanned and
entered into the EMAP database by WED. All data collected by this study
will be publicly available following verification and validation of the
data sets. Data will be made available over the EMAP Website and through
the STORET database.
All data sets generated by this study will be made available on the EMAP
public web site. These data sets will be described (metadata) and a
quality assessment provided. All such data set descriptions will be made
available for inclusion in the EMAP Data Directory/Data Catalog,
accessible on the EMAP web site. In addition, steps will be taken to
assure their continuing availability.
Peck, D.V., Lazorchak, J.M., and Klemm, D.J., in prep.,
Environmental Monitoring and Assessment Program—Surface
waters—Western Pilot Study field operations manual for wadable streams
[Draft, April 2000]: Corvallis, Ore., U.S. Environmental Protection
Agency, 230 p.
Scientific Investigations Report 2006-5117: Comparison of Macroinvertebrate Community Structure between Two Riffle-Based Sampling Protocols in Wyoming, Colorado, and Montana, 2000-2001 by David A. Peterson and Jeremy R. Zumberge
Abstract: Peterson, D.A., Wright, P.R., and Zumberge, J.R., A Case Study for Comparison of NAWQA and EMAP Protocols for Benthic Macroinvertebrates and Habitat: San Jose, Calif., National Water-Quality Monitoring Council, 5th National Monitoring Conference, May 7-11, 2006. View a poster presented at the conference: Sheet 1 (PDF 1.21 mb), Sheet 2 (PDF 1.65 mb)
To view the PDF document, you need the Adobe Acrobat® Reader installed on your computer. (A free copy of the Acrobat® Reader may be downloaded from Adobe Systems Incorporated.)
Scientific Investigations Report 2007-5130: Ecological Status of Wyoming Streams, 2000–2003 by David A. Peterson, Eric G. Hargett, Peter R. Wright, and Jeremy R. Zumberge
3162 Bozeman Avenue
Helena, MT 59601
Wyoming-Montana Water Science Center