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

2 Fish kills Organismal anomalies Changes in community structure Low biotic index values Violation of biocriteria Define the Case List Candidate Causes Evaluate Data from the Case Evaluate Data from Elsewhere Identify Probable Cause As Necessary: Acquire Data and Iterate Process Identify and Apportion Sources Management Action: Eliminate or Control Sources, Monitor Results Biological Condition Restored or Protected Decision-maker and Stakeholder Involvement Stressor Identification Detect or suspect biological impairment

3 What triggered SI at Pretend Creek? PC1 PC2 Pretend Springs city limit NC1 NC2 Pretend Creek Nearby Creek macroinvertebrate IBI = 22 macroinvertebrate IBI = 64

4 What biological effects are observed? Where & when are they occurring? Where are comparable reference sites? Step 1: Define the Case List Candidate Causes Evaluate Data from the Case Evaluate Data from Elsewhere Identify Probable Cause Detect or Suspect Biological Impairment As Necessary: Acquire Data and Iterate Process Identify and Apportion Sources Management Action: Eliminate or Control Sources, Monitor Results Biological Condition Restored or Protected Decision-maker and Stakeholder Involvement Stressor Identification

5 Defining the biological impairment Identify subset of biological measures to focus & guide SI process Choose wisely, & where possible, aim for specificity SPECIFICITYEXAMPLESSI UTILITY coarsefailure to meet biological criteriatriggering SI process composite ↓ sensitive taxa ↓ EPT taxa listing candidate causes developing conceptual model specific ↓ Paraleptophlebia absence of brook trout grouping sites diagnosing evaluating strength of evidence

6 Example: fish kills in Virginia & West Virginia WHERE?

7 Example: fish kills in Virginia & West Virginia WHAT? WHEN? March–May 2006 Acute phase (mid-March) Chronic phase (March – May) smallmouth bass redbreast sunfish VA redhorse sucker WV smallmouth bass northern hogsucker May 25–31, 2006 Acute phase only

8 PC1 PC2 Pretend Springs city limit NC1 NC2 Pretend Creek Nearby Creek Site EPT taxa richness (% of PC1) Defining the case for Pretend Creek

9 PC1 PC2 Pretend Springs city limit NC1 NC2 18 EPT genera brook trout 8 EPT genera no brook trout Pretend Creek Nearby Creek

10 Make a map Gather information on potential sources, stressors, and exposures Develop a conceptual model Engage stakeholders Develop “final” list Define the Case Evaluate Data from the Case Evaluate Data from Elsewhere Identify Probable Cause Detect or Suspect Biological Impairment As Necessary: Acquire Data and Iterate Process Identify and Apportion Sources Management Action: Eliminate or Control Sources, Monitor Results Biological Condition Restored or Protected Decision-maker and Stakeholder Involvement Stressor Identification Step 2: List Candidate Causes

11 forest PC1 PC2 Pretend Springs city limit NC1 NC2 forest dairy farm subdivision unimpaired site impaired site WWTP industrial facility dam Include pollution sources & other environmental conditions or factors that affect which candidate causes are listed

12 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

13 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 Combining stressors Warnings – Avoid combining causes without an underlying model – Avoid broad candidate cause definitions – Don’t lose independent effects of individual causes

14 Example: Willimantic River, CT POTW MR3 MR1 1. Toxicity from metals, ammonia, or complex mixture 2. Removal of organisms during high flows 3. Loss of interstitial habitat due to settled particles 4. Asphyxiation due to low dissolved oxygen 5. Mortality due to thermal stress 6. Taxa loss due to altered food resources

15 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

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17 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 Metals Sediments Nutrients Dissolved oxygen Temperature Ionic strength Flow alteration Unspecified toxic chemicals

18 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 SOURCE STRESSOR BIOTIC RESPONSE

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20 “Generic” conceptual model for sediment

21 Conceptual model components in CADDIS origination points, areas, or entities that release or emit agents biological results of exposure to proximate stressor stressors that directly induce biological effect of concern other stressors that influence or are influenced by the focal stressor changes that affect delivery of agents to stream

22 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

23 Case-specific conceptual models: Long Creek, ME ↓ dissolved oxygen ↑ temperature ↓ large woody debris ↓ brook trout ↓ EPT taxa ↑ non-insect taxa ↑ HBI score detention basins Δ flow regime Δ water velocity ↓ water depth ↓ wetted channel ↑ rate or magnitude of flow fluctuations ↑ toxic substances ↑ NaCl ↑ ionic content ↑ metals↑ organics↑ pesticides ↑ NH 3 ↑ sediment ↑ suspended sediment ↑ deposited sediment ↑ autochthony ↑ autochthonous food resources ↓ allochthonous food resources instream impoundment watershed devegetation channel alteration riparian devegetation impervious surfaces industrial processes lawn care & landscaping landfill leachate sanding, salting & plowing instream deposits

24 ↓ dissolved oxygen ↑ temperature ↓ large woody debris ↓ brook trout ↓ EPT taxa ↑ non-insect taxa ↑ HBI score detention basins Δ flow regime Δ water velocity ↓ water depth ↓ wetted channel ↑ rate or magnitude of flow fluctuations ↑ toxic substances ↑ NaCl ↑ ionic content ↑ metals↑ organics↑ pesticides ↑ NH 3 ↑ sediment ↑ suspended sediment ↑ deposited sediment ↑ autochthony ↑ autochthonous food resources ↓ allochthonous food resources instream impoundment watershed devegetation channel alteration riparian devegetation impervious surfaces industrial processes lawn care & landscaping landfill leachate sanding, salting & plowing instream deposits Case-specific conceptual models: Long Creek, ME

25 Case-specific conceptual models: Little Scioto River, OH source proximate stressor response KEY additional step in causal pathway ↑ fish weight ↑ DELT anomalies ↑ % tolerant invertebrates ↓ % mayflies channel modification ↑ pool depth ↓ woody debris ↑ un-ionized ammonia (NH 3 ) ↑ algae ↑ pH ↓ dissolved oxygen ↑ BOD↑ TOC landfill leachate ↑ metals↑ PAHs ↑ total ammonia (NH NH 3 ) ↓ riffles ↑ sediment ↑ channel incision ↑ nutrients (N and/or P) municipal waste fertilizer use industrial effluent combined sewer overflow hazardous waste site leachate ↑ UV light

26 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

forest PC1 PC2 Pretend Springs city limit NC1 NC2 forest dairy farm subdivision unimpaired site impaired site WWTP industrial facility dam Let’s go back to Pretend Creek…

28 Developing a conceptual model for Pretend Creek CANDIDATE CAUSES? KNOWN IMPAIRMENTS ↓ EPT richness↓ trout abundance industrial facilities subdivision KNOWN SOURCES urbanizationdam dairy farm Candidate cause – hypothesized cause of impairment Proximate stressor – stressor that directly induces biological effect of interest

29 EXAMPLE CANDIDATE CAUSES ↓ dissolved oxygen↑ metals↑ temperature Developing a conceptual model for Pretend Creek industrial facilities subdivision KNOWN SOURCES urbanizationdam dairy farm KNOWN IMPAIRMENTS ↓ EPT richness↓ trout abundance

30 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

31 Conceptual model components in CADDIS origination points, areas, or entities that release or emit agents biological results of exposure to proximate stressor stressors that directly induce biological effect of concern other stressors that influence or are influenced by the focal stressor changes that affect delivery of agents to stream

32 An example conceptual model for Pretend Creek…

33 dairy farm ↓ dissolved oxygen ↑ metals ↑ temperature ↓ EPT richness ↓ brook trout abundance urbanizationsubdivision industrial facilities ↑ impervious surfaces ↑ nutrients ↑ primary producers pesticides ↓ riparian cover ↓ DO-sensitive taxa ↓ coldwater taxa animal wastes industrial effluent ↑ heated surface runoff ↑ DELTs ↑ parasitism & disease ↑ gasping behavior industrial leachate ↑ toxics in surface runoff septic systems deicers ↑ respiration & decomposition ↓ metal-sensitive taxa dam ↑ water retention