6/06/2017  |   11:15 - 11:30   |  301A

Challenges of Implementing Nationally Consistent Assessments of Aquatic Resources, Now and in the Future. Managing our water resources requires information at a variety of scales. Researchers continue to develop new tools to assess our streams, lakes, coastal waters and wetlands. Because of inconsistencies in data collection and assessment protocols across jurisdictions, difficulties arise when trying to answer questions about water quality across larger geographical areas. The National Aquatic Resource Surveys (NARS) is an EPA/State and Tribal partnership designed to fill this gap by using consistent approaches to address questions about the condition of the nation’s waters and to track changes over time. In this presentation, we will discuss how this program balances incorporating methodological and analytical improvements with the desire to maintain consistency over time. As each survey is repeated, decisions are made about whether to add, drop or modify indicators. This often requires weighing the importance of continuing with existing, proven methodologies against the potential benefits of incorporating scientific advancements into the NARS program.

Richard Mitchell (Primary Presenter/Author), U.S. Environmental Protection Agency, mitchell.richard@epa.gov;
Richard Mitchell is a biologist with EPA’s Office of Wetland Oceans and Watersheds. He is a team member of the National Aquatic Resource Surveys (NARS) and has led the National Rivers and Stream Assessment (NRSA) for over seven years. In additional to leading NRSA, he has been involved in various effort to develop biological indicators for use in NARS, and more general for the bioassessment community.

Amina Pollard ( Co-Presenter/Co-Author), U.S. Environmental Protection Agency, pollard.amina@epa.gov;


Sarah Lehmann ( Co-Presenter/Co-Author), U.S. EPA, lehmann.sarah@epa.gov;


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6/06/2017  |   11:30 - 11:45   |  301A

THE CONCEPT OF REFERENCE CONDITION, REVISITED Ecological assessments of aquatic ecosystems depend on the ability to compare current conditions against some expectation of how they could be in the absence of significant human disturbance. The concept of a ‘‘reference condition’’ is often used to describe the standard or benchmark against which current condition is compared. If assessments are to be conducted consistently, then a common understanding of the definitions and complications of reference condition is necessary. A 2006 paper (Stoddard et al., 2006, Ecological Applications 16:1267-1276) made an early attempt at codifying the reference condition concept; in this presentation we will revisit the points raised in that paper (and others) and examine how our thinking has changed in a little over 10 years. Among the issues to be discussed: (1) the “moving target” created when reference site data are used to set thresholds in large scale assessments; (2) natural vs. human disturbance and their effects on reference site distributions; (3) circularity and the use of biological data to assist in reference site identification; (4) using site-scale (in-stream or in-lake) measurements vs. landscape-level human activity to identify reference conditions.

John Stoddard (Primary Presenter/Author), U.S EPA, Office of Research and Development, Pacific Ecological Systems Division, Corvallis, OR, Stoddard.John@epa.gov;


Charles Hawkins ( Co-Presenter/Co-Author), Utah State University, chuck.hawkins@usu.edu;


Jan Stevenson ( Co-Presenter/Co-Author), Michigan State University, rjstev@cns.msu.edu;


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6/06/2017  |   11:45 - 12:00   |  301A

THE ROLE OF TEMPORAL VARIABILITY IN ESTIMATING REFERENCE CONDITIONS: IMPLICATIONS FOR THE ACCURACY OF ECOLOGICAL ASSESSMENTS Biological assessments seek to determine whether observed conditions are outside the range of naturally occurring conditions (RNOC) at a site. Most attempts to estimate the RNOC account for natural spatial variation in assemblages among reference sites and implicitly assume that residual variation is accounted for using a space-for-time substitution. For example, multitaxon distribution models are used in O/E indices to predict the expected assemblage composition at individual test sites, to which observed assemblages are compared. The precision of O/E indices, variance in reference site values, is used to set thresholds for determining departure from the RNOC. Recent research has shown that reference site assemblages exhibit different temporal dynamics and that O/E index precision can vary with physiographic setting. For example, assemblages in arid regions appear to be more temporally dynamic than those in more mesic regions, and arid region O/E indices have relatively low precision. Such results suggest site- or region-specific condition thresholds are needed to manage rates of under versus over protection. We observed that thresholds derived from large-scale versus smaller, region-specific data sets can substantially affect inferences regarding the extent of stream kilometers assigned to different condition classes.

Scott Miller (Primary Presenter/Author), BLM/USU National Aquatic Monitoring Center, Department of Watershed Sciences, Utah State University, scott.miller@usu.edu;


Charles Hawkins ( Co-Presenter/Co-Author), Utah State University, chuck.hawkins@usu.edu;


Jennifer Courtwright ( Co-Presenter/Co-Author), Utah State University National Aquatic Monitoring Center, jennifer.courtwright@usu.edu;


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6/06/2017  |   12:00 - 12:15   |  301A

Solutions for problem of dynamic target populations in interpreting long-term stream surveys Stream surveys are typically designed under the assumption that the target population is static. However, this population can fluctuate over the course of long-term surveys, particularly in arid regions like California. Variable weather patterns and changes in land use affect flow patterns, meaning that the inclusion of a reach in the target population is not constant. Dynamic target populations complicate comparisons of surveys across years: for example, in dry years, surveys may over-represent streams sustained by effluent, giving an inaccurate impression of degradation relative to wet years. Additionally, programmatic changes (e.g., choices to delay sampling in one year) and variability among practitioners (e.g., subjective choices to reject a site) may exacerbate the problem. California is developing a multi-pronged effort to address these challenges that includes: 1) assessment tools that work in the range of flow conditions in the target population, including streams in an intermittent or ephemeral state, 2) hydrologic models to characterize the dynamic flow status of stream segments in a standardized and objective way and 3) a framework to assess the variable representativeness of probabilistic sites.

Raphael Mazor (Primary Presenter/Author), Southern California Coastal Water Research Project, raphaelm@sccwrp.org;


Peter Ode ( Co-Presenter/Co-Author), California Department of Fish and Wildlife, Peter.Ode@wildlife.ca.gov;


Andrew Rehn ( Co-Presenter/Co-Author), California Department of Fish and Wildlife, Andy.Rehn@wildlife.ca.gov;


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6/06/2017  |   12:15 - 12:30   |  301A

CONSISTENCY IN RIVER HEALTH ASSESSMENT METHODS: A PERSPECTIVE FROM THE INTERFACE BETWEEN SCIENCE AND MANAGEMENT This paper examines how trends in the Australian water sector of shrinking interest in/budgets for national river health assessment, greater localism in water management, growing demand for diagnostic indicators of river health, and normal scientific progress, affect five factors thought by Nichols et al. (2016) to underpin nationally consistent river assessment programs. We consider when these effects are large enough to warrant a change in assessment methods, and whether such changes are likely to reduce the consistency of assessment results. It is argued that i) consistency in assessment methods should be encouraged, ii) however, over time, changes to assessment methods are unavoidable, and some changes should be encouraged even though they will reduce consistency in results through time, and iii) characterizing long-term trends in river health will therefore require an understanding of the congruence in the results of assessments based on current and new methods. We then examine whether a well-developed framework for comparing assessment results – FARWH (Framework for Assessing River and Wetland Health) – is robust to the expected changes to methods arising from the water sector trends.

Ralph Ogden (Primary Presenter/Author), University of Canberra, ralphogden4@gmail.com;


Susan Nichols ( Co-Presenter/Co-Author), University of Canberra, Australia, Sue.Nichols@canberra.edu.au;


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