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Steps 1 & 2: Defining the case & listing candidate causes for the Truckee River case study

Steps 1 & 2: Defining the case & listing candidate causes for the Truckee River case study. 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.

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Steps 1 & 2: Defining the case & listing candidate causes for the Truckee River case study

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  1. Steps 1 & 2: Defining the case & listing candidate causes for the Truckee River case study

  2. 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

  3. Defining the biological impairment • Identify subset of biological measures to focus & guide SI process • Choose wisely, & where possible, aim for specificity

  4. Let’s start defining your case…

  5. Defining the case: what, where & when 1. What biological effects do you want to focus on? BUGS? FISH?

  6. Defining the case: what, where & when 2. Where are your impaired & reference sites?

  7. Defining the case: what, where & when Which biological variables? invertebrates fish Where does the biological variable change among your sites? Which are your impaired and reference sites? Which time scale?

  8. Defining the case: what, where & when To Do: • Load relevant data files Siteinfo Metrics • Merge files • Make boxplots for each biological response variable

  9. 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

  10. Let’s start by assembling a map…

  11. 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

  12. Let’s start listing your candidate causes…

  13. Listing candidate causes: initial brainstorming • What sources are in watershed? • What stressors could be causing effects?

  14. 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

  15. Based on our brainstorming, let’s start developing a conceptual model…

  16. 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

  17. 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

  18. 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

  19. Keeping all that in mind, let’s start drawing!

  20. The “final” list of candidate causes • Fill in with final list…

  21. Now that we have a diagram, where do the data fit in?

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