National Aquatic Resource Surveys

1. National Aquatic Resource Surveys Wadeable Streams Assessment Overview November, 2007

2. Purpose of Surveys • Provide statistically-valid, scientifically defensible reports on the condition of U.S. waters • Answer key questions: • Extent of waters supporting healthy ecosystems, recreation? • Extent of resource affected by key water quality problems/stressors? • Is water quality improving? • Are we spending pollution control dollars wisely?

3. Why conduct surveys? • Critiques of monitoring programs by GAO, NAS, and others • Report on extent of waters supporting goals of CWA as called for in Section 305 (b) • Census is cost-prohibitive • Support EPA strategic plan

4. National Aquatic Resource Survey Schedule

5. Basic Components of Surveys • Randomized design to report on conditions of each resource at national, regional, and state (optional) scale • 1,000 sites for national & regional scale in lower 48 • Total of 2,500 needed for state scale • Standard field and lab protocols for core indicators • National QA program and data management • Nationally consistent and regionally relevant data interpretation and reports

6. First statistically-valid report on the condition of the Nation’s streams Baseline from which to track changes over time Collaboration among EPA, states, tribes and other partners Wadeable Streams Assessment Wadeable streams are perennial streams, creeks, and small rivers that are shallow enough to be sampled using methods that involve wading in the water.

7. Wadeable Streams Assessment - Key Findings The WSA found 28% of streams in good condition, compared to least-disturbed reference condition. Across the US 25-30% of streams have high levels of nutrients or excess sedimentation. These streams are twice as likely to have poor biology. Biological Condition of Streams (Index of Biotic Condition)

8. Approach • Sampled 1392 random sites using standardized field and lab protocols once during summer base flow • Implemented rigorous QA program • Trained and audited all crews • Revisited 10% of sites • Reprocessed 10% of biological samples • Supported state enhancements to extend use of survey • State scale surveys • Additional biological indicators • Methods comparability studies

9. Indicators of Biological Condition • Why benthic macroinvertebrates? • Used by most states as indicator of biological condition • Integrate the effects of stressors over time • Important food source for game and non-game fish • Index of biotic integrity (IBI) incorporating 6 metrics of benthic community health • Taxa loss based on comparison of taxa observed in sample to taxa expected at site

10. Stressors in Streams • WSA measured key indicators of stress • Nitrogen • Phosphorus • Salinity • Acidification • Streambed sedimentation • In-stream fish habitat • Riparian vegetation cover • Human influence in riparian zone • WSA evaluated the relative risk of stressors to biological condition

11. Biological Condition – Index of Biological Condition The WSA found 28% of streams in good condition, compared to least-disturbed reference sites in each of 9 regions. Biological Condition of Streams (Index of Biotic Condition)

12. Biological Condition - Taxa Loss Across the country, 42 percent of streams have retained 90 percent of their expected taxa. Taxa are groups of organisms, such as family, genus, species.

13. Total Phosphorus Concentration Ranges by Ecological Region

14. Total Nitrogen Concentration Ranges by Ecological Region NAP SAP TPL WMT Total N (ug/L)

15. Stressors and their Relative Risk to Biological Condition

16. Indicators for Next Survey(proposed) • Aquatic biology • Fish community • Periphyton and phytoplankton • Macroinvertebrates • Recreational / human health • E. Coli, enterococci • Fish tissue contaminants (e.g., Hg) • Stressors • Nutrients • Excess sedimentation • Physical habitat (riparian and instream) • Salinity, acidification