Potomac River basin-wide stream habitat condition index & benthic macroinvertebrate index

1. Potomac River basin-wide stream habitat condition index & benthic macroinvertebrate index Presented to the CBP Non-Tidal Water Quality Workgroup 2/13/2008 Claire Buchanan Interstate Commission on the Potomac River Basin

2. ICPRB “Interstate Compact Commission” Mission - help Potomac basin states and federal government to enhance, protect, and conserve the water and associated land resources A Goal - promote watershed-based management protective of ecosystems and water resources • basin-wide indicators www.potomacriver.org

3. Basin-Wide Indicators Potomac Estuary & Chesapeake Bay Led inter-agency development of IBIs for • Phytoplankton (PIBI) • Zooplankton (ZIBI) – in high salinity waters Supporting CBP development & uses of • Food Availability Index (FAI) - anadromous fish • Benthos (BIBI) – soft-bottom macroinvertebrates • Habitat Suitability Indexes – fish Developing • Phytoplankton Habitat Index - water quality parameters • Indicators of Tidal Embayment Status Potomac Non-Tidal Wadeable Streams/Rivers DevelopedLeAnne Astin (2006, 2007) • Stream Habitat Condition Index • Basin-wide Index of Biotic Integrity (for benthic macroinvertebrates) www.potomacriver.org

4. What the individual programs say about benthic macroinvertebrates:

5. Advantages of Basin-Wide Indicators • Larger data sets • Metrics are more rigorously tested • Broader geographic distribution • Less unintentional bias in results • More reference sites • Thresholds for “good” and “bad” are more accurate • Consistent scoring across state boundaries • Inequalities due to different scoring protocols minimized

6. Calibration Data Sets • MD Biological Stream Survey (MBSS) 1995 - 1997 (n = 290) probabilistic sampling • PA Unassessed Waters/State-Wide Surface Waters Assessment (UW/SSWAP) 1997 – 2001 (n = 269) probabilistic sampling • VA Ambient Water Quality Monitoring Program (AWQM) 1994 - 2000 (n = 428) targeted sampling • WV Watershed Assessment Program (WAP) 1996 – spring 2001 (n = 336) census sampling Total n = 1,323

7. Analysis Approach • Resolve method and data comparability issues • Merge habitat, water quality, and macroinvertebrate data provided by multiple monitoring programs (Access database) • targeted, random-stratified, and census study designs can be combined if data arerepresentative of the range of conditions • Establish uniform benchmarks to evaluate key habitat parameters common to all programs • Anthropogenic Alteration - Instream Condition • Bank Stability - Riparian Zone • Channel Alteration - Substrate Quality • Habitat Heterogeneity • pH - Conductivity

8. Analysis Approach (cont.) • Identify reference and degraded habitats in each physiographic region • modified Relative Status Method • Use reference and degraded sites to develop Habitat Condition Index ratings • Select robust, discriminatory biological indicators (62 tested, 7 selected) • # EPT taxa - % Dominant taxon • Hilsenhoff Family Biotic Index - % EPT • % Clingers - Taxa Richness • % Collectors

9. Analysis Approach (cont.) • Develop standardized metrics and expectations from reference site data • 1-3-5 scoring • Sum of scored metrics  multi-metric BIBI • Test sensitivity of biological metrics and index • Discrimination efficiencies; classification efficiencies • Develop BIBI ratings from reference data distributions • Good is >50th %ile, Fair is 5th – 50th %ile, Poor is <5th %ile • Validate BIBI by physiographic region • additional data, jackknife procedure

10. What the individual programs say about benthic macroinvertebrates:

11. What they all say when stitched together with the Basin-wide IBI: Status is measured against a common pool of “reference sites” in each physiographic region No mention of WQ Standards “impairments”

12. Some Findings • Anthropogenic Alteration is a strong habitat metric but is being phased out by many programs • “grazing”, “disruptive pressure”, “aesthetics”, “remoteness” • Relative abundance (P/A) data can apparently be used with count data at least when data are collected with variants of the RBP protocol • Metric discrimination efficiency can vary depending on physiographic region • e.g., EPT metric is a strong in Piedmont &Valley regions but weak in Highlands region

13. Some Findings • Good separation of reference and degraded site BIBIs (good classification efficiency) • Positive relationship between BIBI and habitat condition index • General agreement between the BIBI and the individual state assessments … but some notable discrepancies

14. Some Findings Note: Only validation data sets were used in these comparisons

15. To-Do List • Collaborate with Non-Tidal Water Quality Workgroup (NTWQW) staff Katie Foreman (acquire 2004-2006 water quality, habitat, and benthic macroinvertebrate data sets) • February – May 2008 • Re-validate ICPRB Habitat Condition Index and Basin-wide Biotic Index of Integrity for Potomac R. • June – September 2008 • Request NTWQW review of 2004 – 2006 results (maps, report with comparisons to state assessments) • Fall 2008 • ICPRB 2008 annual report • Spring 2009

16. References • Astin, L.E. 2006. Data synthesis and bioindicator development for nontidal streams in the interstate Potomac River basin, USA. Ecological Indicators 6: 664-685. • Astin, L. E. 2007. Developing biological indicators from diverse data: The Potomac Basin-wide Index of Benthic Integrity (B-IBI). Ecological Indicators 7: 895-908.