Upload
kerry-scott
View
218
Download
0
Embed Size (px)
DESCRIPTION
3 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
Citation preview
Steps 1 & 2: Defining the case & listing candidate causes for the Truckee River case study
2
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
• What biological effects are observed?
• Where & when are they occurring?
• Where are comparable reference sites?
3
Defining the biological impairment
• Identify subset of biological measures to focus & guide SI process
• Choose wisely, & where possible, aim for specificity
SPECIFICITY EXAMPLES SI UTILITY
coarse failure to meet biological criteria triggering SI process
composite↓ sensitive taxa
↓ EPT taxalisting candidate causes
developing conceptual model
specific↓ Paraleptophlebia
absence of brook trout
grouping sitesdiagnosing
evaluating strength of evidence
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?invertebratesfish
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:1. Load relevant data files
SiteinfoMetrics
2. Merge files
3. Make boxplots for each biological response variable
9
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
• Make a map• Gather information on
potential sources, stressors, and exposures
• Develop a conceptual model
• Engage stakeholders• Develop “final” list
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
1. What sources are in watershed?
2. What stressors could be causing effects?
14
• 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
15
Based on our brainstorming, let’s start developing a conceptual model…
16
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
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?