EXPECTED CONDITION

transcript

EXPECTED CONDITION

Introduction to Some Basic Concepts

for the Development of

Colorado’s Conceptual Model

PROJECT OBJECTIVES

Develop a ‘top down’ reference stream/reach screening approach

Develop a process to identify ‘least disturbed’ reference sites in any bio-physical stratum

Key: practical, based on readily available data, reproducible, regionally flexible

Develop a Protocol or Guidance document that will reflect Colorado’s approach to Biological Assessments

“The true health of our aquatic environments is reflected by the biological communities that reside within them”

Prof. J. Karr

University of Washington

WHAT ARE REFERENCE CONDITIONS?(from EPA)

• Reference conditions represent the best biological conditions that can be found in a body of water that has not been impacted by humans.

REFERENCE CONDITIONCAN BE:

• Minimally Disturbed Condition

• Least Disturbed Condition

• Best Attainable Condition

MINIMALLY DISTURBED CONDITION

• Condition in the absence of significant, or minimal human disturbance (e.g., “natural”, “pristine”, or “undisturbed”)

• An absolute. Some regions might have no sites that meet minimal disturbance criteria.

• MDC changes little over time, due to natural processes

• Stable benchmark• Derived from minimally disturbed reference sites

LEAST DISTURBED CONDITION

• Best available given today’s state of the landscape• Found in conjunction with the best available

physical, chemical, and biological habitat given today’s state of the landscape

• Relative. No matter how disturbed the region, some sites are likely less disturbed than others.

• Can change over time as land use and management practices change

• Derived by characterizing least disturbed reference sites

BEST ATTAINABLE CONDITION

• Best Attainable Condition - this condition is equivalent to the ecological condition of (hypothetical) least disturbed sites where the best possible management practices are in use

COLORADO’S PROPOSED DEFINITION

Expected Condition – the physical, chemical and biological conditions found at reference sites should represent the best attainable conditions that can be achieved by similar streams within a particular geographic region, given today’s state of the landscape

THERE ARE TWO APPROACHES TO ESTIMATE THE REFERENCE (EXPECTED)

CONDITION:

– Classification predicts the expected biotic condition of a waterbody from previously observed associations between biotic attributes and categorical descriptors of a waterbody’s environmental setting.

– Modeling predicts the expected biotic condition by mathematically describing how biota vary along environmental gradients.

IMPROPER CLASSIFICATION LEADS TO BAD DECISIONS:

Scientist,Manager, orRegulator

Stakeholder

THE EXPECTED CONDITION OF A SITE WILL ALWAYS BE SOMEWHAT “FUZZY”

BECAUSE:

o Un-impaired sites are not static - they are in dynamic equilibria.

o There is measurement error associated with estimating the value of an indicator.

o There is variance associated with the effects of un-measured, naturally occurring factors.

Reference Site Selection

THE WORLD IS NATURALLY HETEROGENEOUS AND “EXPECTED”

MAY NOT BE OBVIOUS

We need to establish the correct match between an assessed site and its

expected condition, so we need …

GOOD REFERENCE SITES THAT

• Mimic natural gradients of the region of interest, and ….

• are representative of the stream and habitat of interest

REFERENCE SITE SELECTION IS:

• An iterative screening process for selecting sites • That are minimally or least disturbed by

human activities and resultant stressors• That are representative of the aquatic

resource in the region of interest

THE PROBLEM OF REPRESENTATIVENESS

o This problem really boils down to whether the range of environmental and biological conditions in the population of reference sites is equivalent to the range that would occur in the population of all other sites of interest.

o Reference site ‘quality’ will almost always vary across classes of sites, so we must be careful about what we mean by “reference”.

ACCOUNTING FOR NATURAL VARIABILITY – HOW MUCH IS ENOUGH?

o How much we need to account for is a function of how small of a response we want/need to detect, which needs to be decided by stakeholders up front!!!

THE ROLE OF REFERENCE SITES IN CLASSIFICATION AND MODELING:

o The use of reference sites is an empirical approach to estimating Reference Condition.

o Accurate and precise predictions from reference site data depend on:

– Agreed upon and acceptable criteria for defining reference site quality,

– Acceptable means of extrapolating/interpolating.

A SIMPLE CONCEPTUAL MODEL:The key is to identify common patterns of

biological responses to human disturbances

Human Activities (Disturbance)

Stressors(Habitat Responses)

Biological Responses

Urbanization

Channelization Levees Roads/Culverts Erosion MWTPs/CSOs Septic systems Imperviousness Fragmentation

Ag/CAFO/Silviculture Grazing Harvest Dams Channelization Diversions Levees Roads/Culverts Erosion Fertilizer Pesticides Compaction Fragmentation

Mining/ Drilling Extraction Metals Liming Tailings Valley Fill Diversions Roads/Culverts Erosion Petroleum Pipelines Fragmentation Compaction

Industry/Power Gen. Dams Stacks Liming Wastewater WTP/CSOs Roads/Culverts Channelization Revetments Imperviousness Fragmentation

Altered Biological Structure/Function

Human Activity

Stressors(Habitat change)

Biological Responses

(from Bryce et al. 1999. J. Am. Wat. Resour. Assoc. 35:23-36)

A more complex conceptual model

Habitat Flow Sediment Nutrient Oxygen Temperature Toxics

EXTENSIVE DATA

• Identify sources of complete coverages– GIS resources?– Geo-Referenced databases?

• Sources of data– At the landscape screening level

• Land use/cover (TM imagery; other satellite imagery)

• Roads• Population density/points sources• Mines• Feedlots• …

OFFICE DATA

• Identify sources of candidate sites– Air photos, digital orthophoto quads, maps

• Sources of data– Terraserver– USGS topo maps/local maps– National High Altitude Photography

(NHAP)– Satellite imagery

SITE RECONNAISSANCE

• By air• By ground site visit• ID disturbances missed by the coarser filters• Local knowledge/local land managers• Input from Best Professional Judgement

SITE MEASUREMENTS

• Apply routine field protocol– EMAP– USGS– STATE– RIVPACS

• To identify disturbances missed by coarser screens:– Riparian habitat– Physical habitat– Water quality– Biota

SOME EXAMPLES OF CRITERIA TO SELECT REFERENCE SITES

CRITERIA SET # 1

• Drainage: entirely within subregion• Land use: >80% forest; no ag/urban; no recent

disturbance, e.g., construction; clearcutting• Habitat: No cattle in w/s; no disturbances• Channel: Characteristic of region• Riparian veg: > 30m buffer for most of w/s• Instream substrate: no significant siltation or

embeddedness• Water Quality: No point sources; no recent spills;

“Filters”: exclude all sites with:

• sulfate over 400 ueq/L (mine drainage)• acid neutralizing capacity less than 50 ueq/L (acid rain)• average RBP habitat score less than 16 (habitat)• total phosphorus over 100 ug/L (nutrient enrichment)• total nitrogen over 750 ug/L (nutrient enrichment)• chloride over 100 ueq/L (general watershed disturbance• total benthic count less than 100 individuals (inadequate sample)

CRITERIA SET # 2

no channelization no upstream impoundments no known point source dischargers

dissolved oxygen greater or equal to 5 ppm urban land use less than 15% in catchment mining and/or logging affecting less than 15% in catchment

forest land use (or other natural wetland, grassland) greater than 70% in catchment

riparian buffer width greater or equal to 18 m

Criteria for Alaska Reference Sites (Must meet all criteria)

EXAMPLE OF CRITERIA FROM MISSOURI

• Wastewater treatment plants and other point sources• Confined animal feeding operations• Instream habitat• Riparian habitat• Land use and land cover, broad scale• Land use and land cover, site specific• Physical and chemical water parameters• Biological metrics• Faunal assemblages• Altered hydrologic regime • Representativeness

Bioassessment and Biocriteria Program Development Timeline

INITIAL ASSESSMENT PHASE

18 MO – 6 YEARS

Start-Up Tasks: Logistics

Acquire Staffing: Professional biologists with

expertise & training Database manager Interns/technicians (field work,

lab tasks

Acquire Facilities & Equipment: Outfit laboratory and field facility Office accommodations Database support infrastructure

Methods Development: Review and select candidate

methods and protocols Consider MQO/DQO needs Test methods for applicability Analyze test results – select

methods

Start-Up Tasks: Implementation

Initiate Field Sampling: Review spatial designs Develop QA/QC and QAPP Develop sampling plans in

accordance with monitoring strategy

Pilot assessments

Classification Issues: Consider spatial stratification

issues Develop and test reference

condition approach Select and sample reference

sites Develop index development

and calibration strategy

Program Implementation

Biocriteria Development: Select candidate metrics and/or

assessment tools Develop refined uses -

narratives Test metrics and develop

calibrated indices Evaluate via bioassessments

Water quality Program Support: Develop capacity to support

WQ programs (WQS/UAAs, TMDLs, permits, planning)

Formalize water quality program support as capacity is developed

Program Maintenance

Biocriteria Development: Refine metrics and develop

calibrated indices Develop reference benchmarks

for calibrated indices according to classification scheme and by major aquatic ecotype

Water quality Program Support: Fully functioning bioassessment

program supports WQS (UAAs, aquatic life use support) and basic program needs (305b/303d)

Program development should be fully initiated – e.g., integrated chemical, physical, and biological database supports criteria & policy development

5 – 10 YEARS

FULL ASSESSMENT PHASE

0-18 MONTHS

INITIAL DEVEOPMENT PHASE

12-24 MONTHS

INITIAL IMPLEMENTATION PHASE

Quality Improvement Process

Continuously evaluate program

Evaluate effectiveness of initial decisions – make needed adjustments

Cold Water Aquatic Life -- Streams -- Fish

Least Disturbed

Disturbed

Minimal Disturbance

Disturbed

Biological Integrity

Attainable

Least Disturbed

Disturbed

Attainable =

Mountain streams Perennial Adequate flow No human Impact

Mountain streams Perennial Some human impact Near roads, ISDS

Mountain streams Mine-impacted Heavy human impacts

Increasing Human Disturbance

B I O L O G I C A L C O N D I T I O N

Cold Water Aquatic Life -- Streams -- No Fish

Least Disturbed

Disturbed

Minimal Disturbance

Disturbed

Attainable

Least Disturbed

Disturbed

Attainable =

Mountain streams Headwaters Lack adequate flow for fish No human Impact

Mountain streams Headwaters Some human impact Near roads, ISDS

Mountain streams Mine-impacted Heavy human impacts

Transitional Zone Aquatic Life -- Streams -- Fish

Least Disturbed

Disturbed

Minimal Disturbance

Disturbed

Attainable

Least Disturbed

Disturbed

Attainable =

Transitional streams Perenial/Intermittent Lack adequate flow No human Impact

Transitional streams Hydrologic modification Some human impact Near roads, ISDS

Transitional streams Mine-impacted, degraded Heavy human impacts

Transitional Zone Aquatic Life -- Streams -- No Fish

Least Disturbed

Disturbed

Minimal Disturbance

Disturbed

Attainable

Least Disturbed

Disturbed

Attainable =

Transitional streams Lack adequate flow Ephemeral/Intermittent No human Impact

Transitional streams Ephemeral/Intermittent Some human impact Near roads, ISDS

Transitional streams Ephemeral/Intermittent Degraded Heavy human impacts

Warm Water Aquatic Life -- Streams -- Fish

Least Disturbed

Disturbed

Minimal Disturbance

Disturbed

Attainable

Least Disturbed

Disturbed

Attainable =

Lower elevation streams Perennial/intermittent Adequate flow for fish No human Impact

Lower elevation streams Perennial/Intermittent Some human impact Near roads, ISDS

Lower elevation streams Mine-impacted Heavy human impacts

Warm Water Aquatic Life -- Streams -- No Fish

Least Disturbed

Disturbed

Minimal Disturbance

Disturbed

Attainable

Least Disturbed

Disturbed

Attainable =

Lower elevation streams Ephemeral/intermittent Lack adequate flow No human Impact

Lower elevation streams Ephemeral/Intermittent Some human impact Near roads, ISDS

Lower elevation streams Mine-impacted Heavy human impacts

EXPECTED CONDITION

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