Potomac River Potomac River

basin-wide stream habitat condition indexbasin-wide stream habitat condition index

& benthic macroinvertebrate index & benthic macroinvertebrate index

Presented to the Presented to the CBP Non-Tidal Water Quality WorkgroupCBP Non-Tidal Water Quality Workgroup

2/13/20082/13/2008

Claire BuchananClaire BuchananInterstate Commission on the Potomac River BasinInterstate Commission on the Potomac River Basin

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

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/RiversDeveloped LeAnne Astin (2006, 2007)• Stream Habitat Condition Index• Basin-wide Index of Biotic Integrity (for benthic

macroinvertebrates)

www.potomacriver.org

What the individual programs say about benthic macroinvertebrates:

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

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

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 are representative 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

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

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

What the individual programs say about benthic macroinvertebrates:

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”

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

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

Some FindingsMARYLAND WEST VIRGINIA

Basin-wide IBI Basin-wide IBI

MD MBSS ’00-’01 Poor Fair Good WV WAP ’01-’02 Poor Fair Good

Good 8% 36% 62% Good 4% 44% 90%

Fair 32% 54% 38% Fair 42% 46% 10%

Poor/Very Poor 60% 10% 0% Poor 54% 11% 0%

PENNSYLVANIA “Old” Method VIRGINIA

Basin-wide IBI Basin-wide IBI

PA UW ’02-’03 Poor Fair Good VA AWQM ’00-’02 Poor Fair Good

Non-Impaired 53% 86% 100% Non-Impaired 6% 36% 79%

Slight Impair. 26% 45% 21%

Impaired 47% 14% 0% Mod./Sev. Impair. 68% 19% 0%

Note: Only validation data sets were used in these comparisons

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

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.