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Population Estimates from the National Rivers and Streams Assessment: Looking Beyond Ecoregion-based Subpopulations
Citation:
Peck, D. Population Estimates from the National Rivers and Streams Assessment: Looking Beyond Ecoregion-based Subpopulations. PNW Chapter of the Society for Freshwater Science, La Connor, Washington, November 07 - 09, 2017.
Impact/Purpose:
The EPA National Rivers and Streams Assessment (NRSA), one of the National Aquatic Resource Surveys (NARS) provides information on the status and extent of biological condition in streams and rivers. Information from the NRSA helps EPA and partners meet the reporting requirements of the Clean Water Act, and determine if policies and regulations that are intended to improve ambient water quality in the US are having the desired effects. Assessment reports developed for the NRSA primarily provide estimates of status and extent of resource condition for reporting regions that are aggregates of Omernik Level III ecoregions. Reporting estimates for other subpopulations of interest (e.g., major river basin, land ownership) provides additional insight into how ecological condition may be influenced by, stream size or management strategies that may differ across river basins. This presentation will use data from NRSA to develop condition estimates of biological and stressor indicators for other subpopulations of potential interest to States and regional users of NRSA data. This presentation contributes to SSWR Task 3.01A.
Description:
The EPA National Rivers and Streams Assessment (NRSA), one of the National Aquatic Resource Surveys (NARS), provides information on the status and extent of biological condition in streams and rivers. Information from the NRSA helps EPA and partners meet the reporting requirements of the Clean Water Act, and determine if policies and regulations that are intended to improve ambient water quality in the US are having the desired effects. Assessment reports developed for the NRSA primarily provide estimates of status and extent of resource condition for reporting regions that are aggregates of Omernik Level III ecoregions. The survey design of the NARS also allows individual States to develop their own assessment reports, but are typically constrained by sample size from reporting on any subpopulations within their State. The survey designs for NARS are flexible and allow for other subpopulations of interest to be defined and assessed for condition. Using data from the National Rivers and Streams Assessments, I will present condition estimates of biological and stressor indicators for other subpopulations of potential interest to States and regional users of NARS data. These subpopulations include land ownership, major river basins, and stream size (watershed area or stream order). For this presentation, subpopulation estimates will focus will focus on the western US (EPA Regions 8, 9, and 10), if sample sizes are adequate. Examining status (and possibly change) estimates for subpopulations other than ecoregions provides potential users an opportunity to see how overall results for a state or regions are apportioned among specific types of land use, management strategies, or stream type. Such information provides additional information to refine decisions and strategies to protect or restore aquatic resources within a State or region. Users may choose to define other subpopulations of interest based on the approach described here. This presentation contributes to SSWR Task 3.01A. This is an abstract for a proposed presentation and does not necessarily reflect EPA policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.