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Steps 1 & 2: Defining the case & listing candidate causes. Fish kills Organismal anomalies Changes in community structure Low biotic index values Violation of biocriteria. Detect or suspect biological impairment. Stressor Identification. Define the Case. List Candidate Causes.

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Steps 1 & 2: Defining the case & listing candidate causes

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Steps 1 2 defining the case listing candidate causes

Steps 1 & 2:

Defining the case & listing candidate causes


Steps 1 2 defining the case listing candidate causes

  • Fish kills

  • Organismal anomalies

  • Changes in community structure

  • Low biotic index values

  • Violation of biocriteria

Detect or suspect biological impairment

Stressor Identification

Define the Case

List Candidate Causes

Decision-maker

and

Stakeholder

Involvement

As Necessary:

Acquire Data

and

Iterate Process

Evaluate Data from the Case

Evaluate Data from Elsewhere

Identify Probable Cause

Identify and Apportion Sources

Management Action:

Eliminate or Control Sources, Monitor Results

Biological Condition Restored or Protected


Steps 1 2 defining the case listing candidate causes

macroinvertebrate IBI = 64

PC1

NC1

Pretend Creek

Nearby Creek

Pretend Springs city limit

NC2

macroinvertebrate IBI = 22

PC2

What triggered SI at Pretend Creek?


Steps 1 2 defining the case listing candidate causes

Detect or Suspect Biological Impairment

  • What biological effects are observed?

  • Where & when are they occurring?

  • Where are comparable reference sites?

Stressor Identification

Step 1: Define the Case

List Candidate Causes

Decision-maker

and

Stakeholder

Involvement

As Necessary:

Acquire Data

and

Iterate Process

Evaluate Data from the Case

Evaluate Data from Elsewhere

Identify Probable Cause

Identify and Apportion Sources

Management Action:

Eliminate or Control Sources, Monitor Results

Biological Condition Restored or Protected


Steps 1 2 defining the case listing candidate causes

Defining the biological impairment

  • Identify subset of biological measures to focus & guide SI process

  • Choose wisely, & where possible, aim for specificity


Steps 1 2 defining the case listing candidate causes

Example: fish kills in Virginia & West Virginia

WHERE?


Steps 1 2 defining the case listing candidate causes

smallmouth bass

VA

WV

northern hogsucker

redhorse sucker

smallmouth bass

redbreast sunfish

March–May 2006

Acute phase (mid-March) Chronic phase (March–May)

May 25–31, 2006

Acute phase only

Example: fish kills in Virginia & West Virginia

WHAT?

WHEN?


Steps 1 2 defining the case listing candidate causes

PC1

NC1

Pretend Creek

Nearby Creek

Pretend Springs city limit

NC2

PC2

Defining the case for Pretend Creek

EPT taxa richness (% of PC1)

Site


Steps 1 2 defining the case listing candidate causes

18 EPT genera

brook trout

PC1

NC1

Pretend Creek

Pretend Springs city limit

Nearby Creek

NC2

PC2

8 EPT genera

no brook trout

Defining the case for Pretend Creek


Steps 1 2 defining the case listing candidate causes

Detect or Suspect Biological Impairment

Stressor Identification

  • Make a map

  • Gather information on potential sources, stressors, and exposures

  • Develop a conceptual model

  • Engage stakeholders

  • Develop “final” list

Define the Case

Step 2:

List Candidate Causes

Decision-maker

and

Stakeholder

Involvement

As Necessary:

Acquire Data

and

Iterate Process

Evaluate Data from the Case

Evaluate Data from Elsewhere

Identify Probable Cause

Identify and Apportion Sources

Management Action:

Eliminate or Control Sources, Monitor Results

Biological Condition Restored or Protected


Steps 1 2 defining the case listing candidate causes

Include pollution sources & other environmental conditions or factors that affect which candidate causes are listed

forest

forest

dairy farm

PC1

subdivision

NC1

Pretend Springs city limit

forest

NC2

unimpaired site

impaired site

PC2

WWTP

industrial facility

dam


Steps 1 2 defining the case listing candidate causes

Listing candidate causes

  • Hypothesized causes of impairment

    • Sufficiently credible to be analyzed

    • Focus on proximate stressor, or stressor directly inducing effect of concern

    • May include sources, mechanisms of action, or several causes acting together (causal scenarios)

  • Develop list using:

    • Data from site

    • Info on known or potential sources

    • Existing knowledge from site, region & elsewhere

    • Stakeholder input


Steps 1 2 defining the case listing candidate causes

Combining stressors

  • Strategies

    • Combine if they share causal pathways, modes of action, sources & routes of exposure, or if they interact

    • Re-aggregate stressors that have been unnecessarily disaggregated

    • Identify independently acting stressors that cause the same effect

    • Define effects more specifically

  • Warnings

    • Avoid combining causes without an underlying model

    • Avoid broad candidate cause definitions

    • Don’t lose independent effects of individual causes


Steps 1 2 defining the case listing candidate causes

MR3

MR1

POTW

Example: Willimantic River, CT

1. Toxicity from metals, ammonia, or complex mixture

2. Removal of organisms during high flows

3.Loss of interstitial habitatdue to settled particles

4. Asphyxiation due to low dissolved oxygen

5. Mortality due to thermal stress

6. Taxa loss due to altered food resources


Steps 1 2 defining the case listing candidate causes

Example: fish kills in Virginia & West Virginia

1. Low dissolved oxygen in water

2. Gill damage from ammonia, high pH, or other mechanism prevents uptake of oxygen

3.Altered blood chemistry from nitrite exposure prevents fish from using oxygen

4. Viral, bacterial, parasitic, or fungal infections

5. Mortality from high pH

6. Mortality from pH fluctuations

7. Mortality from ammonia toxicity

8. Toxicity of unspecified substances

9. Starvation due to inadequate food resources


Steps 1 2 defining the case listing candidate causes

  • Metals

  • Sediments

  • Nutrients

  • Dissolved oxygen

  • Temperature

  • Ionic strength

  • Flow alteration

  • Unspecified toxic chemicals

Listing advice for candidate causes

  • 8 common candidate causes

  • Basic information:

    • Definition of candidate cause

    • Sources

    • Site evidence

    • Biological effects

    • When to exclude

    • How to measure

    • Relevant literature reviews

    • Generic conceptual model


Steps 1 2 defining the case listing candidate causes

SOURCE

STRESSOR

BIOTIC RESPONSE

Developing a conceptual model

  • What is it?

    • Diagram showing cause-effect linkages among sources, stressors, & biological effects

  • Used for:

    • Initial brainstorming

    • Analysis framework

    • Communication tool


Steps 1 2 defining the case listing candidate causes

“Generic” conceptual model for sediment


Steps 1 2 defining the case listing candidate causes

origination points, areas, or entities that release or emit agents

changes that affect delivery of agents to stream

other stressors that influence or are influenced by the focal stressor

stressors that directly induce biological effect of concern

biological results of exposure to proximate stressor

Conceptual model components in CADDIS


Steps 1 2 defining the case listing candidate causes

Using the conceptual models in CADDIS

  • The stressor-specific diagrams are there to give you ideas, & get you thinking about what may be happening in your stream

  • Take the parts that make sense for your system & leave the rest

  • Pilfer & modify freely, to generate case-specific diagrams


Steps 1 2 defining the case listing candidate causes

industrial processes

riparian devegetation

instream deposits

channel alteration

watershed devegetation

detention basins

landfill leachate

impervious surfaces

instream impoundment

lawn care & landscaping

sanding, salting & plowing

↑ temperature

↓ dissolved oxygen

↓ large woody debris

↑ autochthony

↑ sediment

Δ flow regime

2

5

↓ allochthonous food resources

↑ toxic substances

↑ suspended sediment

6

Δ water velocity

↑ rate or magnitude of flow fluctuations

1

↑ autochthonous food resources

↑ deposited sediment

↑ organics

↑ metals

↑ pesticides

7

↓ wetted channel

↓ water depth

3

4

↑ ionic content

↑ NaCl

↑ NH3

↓ EPT taxa

↑ non-insect taxa

↑ HBI score

↓ brook trout

Case-specific conceptual models: Long Creek, ME


Steps 1 2 defining the case listing candidate causes

lawn care & landscaping

industrial processes

instream deposits

watershed devegetation

channel alteration

instream impoundment

detention basins

landfill leachate

sanding, salting & plowing

impervious surfaces

riparian devegetation

↑ temperature

↓ dissolved oxygen

↓ large woody debris

↑ autochthony

↑ sediment

Δ flow regime

↓ allochthonous food resources

↑ toxic substances

↑ suspended sediment

Δ water velocity

↑ rate or magnitude of flow fluctuations

↑ autochthonous food resources

↑ deposited sediment

↑ organics

↑ metals

↑ pesticides

↓ wetted channel

↓ water depth

↑ ionic content

↑ NaCl

↑ NH3

↓ EPT taxa

↑ non-insect taxa

↑ HBI score

↓ brook trout

Case-specific conceptual models: Long Creek, ME


Steps 1 2 defining the case listing candidate causes

source

fertilizer use

landfill leachate

municipal waste

industrial effluent

channel modification

hazardous waste site leachate

combined sewer overflow

↑ nutrients (N and/or P)

↑ total ammonia (NH4+ + NH3)

additional step in causal pathway

↑ pH

↑ channel incision

↑ BOD

↑ TOC

↑ UV light

KEY

response

proximate stressor

Case-specific conceptual models: Little Scioto River, OH

↑ sediment

↑ algae

↓ woody debris

↑ pool depth

4

↑ un-ionized ammonia (NH3)

↑ metals

↑ PAHs

↓ riffles

↓ dissolved oxygen

1

2

3

5

6

7

↑ fish weight

↑ DELT anomalies

↑ % tolerant invertebrates

↓ % mayflies


Steps 1 2 defining the case listing candidate causes

Things to keep in mind in model development

  • Think about causal pathways

    • How do sources lead to stressors?

    • How do stressors lead to biological effects?

  • Be as specific as possible

    • You do not need data for every component in your diagram

    • Want to identify potential data sources & types of evidence

    • General vs. specific impairments

  • Be thorough & inclusive

    • You can always eliminate potential sources, pathways, etc. later on, but don’t limit your initial brainstorming


Steps 1 2 defining the case listing candidate causes

forest

forest

dairy farm

PC1

subdivision

NC1

Pretend Springs city limit

forest

NC2

unimpaired site

impaired site

PC2

WWTP

industrial facility

dam

Let’s go back to Pretend Creek…


Steps 1 2 defining the case listing candidate causes

subdivision

urbanization

dam

KNOWN SOURCES

industrial facilities

dairy farm

Candidate cause – hypothesized cause of impairment

Proximate stressor – stressor that directly induces biological effect of interest

↓ EPT richness

↓ trout abundance

KNOWN IMPAIRMENTS

Developing a conceptual model for Pretend Creek

CANDIDATE CAUSES?


Steps 1 2 defining the case listing candidate causes

subdivision

urbanization

dam

KNOWN SOURCES

industrial facilities

dairy farm

↓ EPT richness

↓ trout abundance

KNOWN IMPAIRMENTS

Developing a conceptual model for Pretend Creek

↓ dissolved oxygen

↑ temperature

↑ metals

EXAMPLE CANDIDATE CAUSES


Steps 1 2 defining the case listing candidate causes

Let’s give it a try…

  • Break into groups – 1 group per poster

  • Arm yourselves with sharpies

  • Mark up posters to generate conceptual models for Pretend Creek


Steps 1 2 defining the case listing candidate causes

origination points, areas, or entities that release or emit agents

changes that affect delivery of agents to stream

other stressors that influence or are influenced by the focal stressor

stressors that directly induce biological effect of concern

biological results of exposure to proximate stressor

Conceptual model components in CADDIS


Steps 1 2 defining the case listing candidate causes

An example conceptual model for Pretend Creek…


Steps 1 2 defining the case listing candidate causes

dairy farm

deicers

urbanization

subdivision

pesticides

dam

↑ metals

septic systems

industrial facilities

industrial leachate

industrial effluent

animal wastes

↑ impervious surfaces

↑ nutrients

↑ primary producers

↓ riparian cover

↑ heated surface runoff

↑ toxics in surface runoff

↑ respiration & decomposition

↑ water retention

↑ temperature

↓ dissolved oxygen

↑ DELTs

↓ brook trout abundance

↓ metal-sensitive taxa

↓ coldwater taxa

↓ DO-sensitive taxa

↓ EPT richness

↑ parasitism & disease

↑ gasping behavior


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