Citation:

Doyle, J., R. Hill, S. Leibowitz, AND P. Ringold. Developing a spatial modeling approach to estimate O/E scores within streams and lakes in the conterminous US (CONUS). Annual Meeting of the Pacific Northwest Chapter of the Society for Freshwater Science, Newport, OR, November 06 - 08, 2019.

Impact/Purpose:

EPA’s National Center for Environmental Economics (NCEE) is working to evaluate subjective choices on environmental decisions through tools such as economic willingness-to-pay surveys. To that end, NCEE needs estimates of observed-to-expected (O/E) macroinvertebrate richness that represent current environmental conditions in US lakes and streams. Currently these estimates only exist for several thousand water bodies in the continental United States. We will be using spatial modeling to interpolate values of O/E to unsampled streams and lakes. However, this spatial interpolation raises several methodological questions that have not yet been addressed at the nationwide scale. This presentation acts as a means to open dialogue between experts in the field about our proposed method of spatial interpolation. In addition, this presentation will review previous spatial interpolations done by the USEPA with other measures of taxonomic richness such as multi-metric indices. We hope to further a discussion on how these products may be improved upon from these previous products. Lastly, a review of the USEPA StreamCat and LakeCat products and applications will be done in order to show how these products may be used in future spatial interpolation modeling. This study supports the development of a spatial interpolations of aquatic condition to support economic research being conducted by the National Center for Environmental Economics. It also contributes to an FY21 deliverable under SSWR Research Area 1, Output 2, Product 1, Milestone 2 (“Develop empirical models to interpolate benthic macroinvertebrate observed/expected ratios, or other biological indicator(s) of aquatic ecosystem health, for stream and lake condition from NRSA and NLA surveys to HUC12 or HUC8 units over the conterminous US”).

Description:

The USEPA has estimated macroinvertebrate observed-to-expected (O/E) taxonomic richness for several thousand rivers, streams and lakes throughout the continental United States as part of the National Aquatic Resource Surveys (NARS). However, predicting O/E in unsampled rivers/streams and lakes could help local, state, and federal agencies prioritize areas for conservation or restoration. In addition, this measure of aquatic condition is of great interest to economists as it is readily understood by participants in willingness-to-pay-studies. Our main objective is to produce spatial interpolations of macroinvertebrate O/E across the conterminous US that can be used in an economic analysis to estimate the willingness of individuals to pay for incremental improvements in biological condition near them. However, this work raises several methodological questions that have not been addressed at this scale, such as: How best can we develop and apply models to both streams and lakes? How do we communicate the accuracy and precision achieved in the ecological models to support economic analyses? How will the use of regional reference sites in the development of O/E indices affect interpolations at regional boundaries and are there ways to mitigate these differences for economic analyses? In this presentation, we will review the need for such information, review past approaches, and discuss our proposed approach to model O/E for streams and lakes as well as several challenges we expect to encounter.

Record Details: