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Phase 1 - Problem Formulation
Phase 1 - A key component of the Problem Formulation stage is defining an assessment endpoint to determine what ecological entity is important to protect.
An ecological entity can be:
- A species (for instance: piping plover)
- A functional group of species (for instance: piscivores - i.e., fish eaters)
- A community (for instance: benthic invertebrates)
- An ecosystem (for instance: lake)
- A specific valued habitat (for instance: wet meadows)
- Another entity of concern
Once the entity has been identified, the next step is to determine what specific attribute(s) of the entity is potentially at risk and important to protect. This provides a basis for measurement in the risk assessment.
Determining ecological relevance in specific cases requires professional judgment based on site-specific information, preliminary surveys, or other available information.
Ecological relevance is linked to:
- Nature and intensity of effects
- Spatial and temporal scales of effects
- Potential for recovery
- Level of organization potentially affected
- The entity's role in the ecosystem
More than one level of organization may need to be considered.
It is rarely clear which of these ecosystem components are most critical to ecosystem function. Further, professionals and the public don't always agree on which are most valuable. This increases the challenge in choosing which ecological characteristics to protect. Three principal criteria clarify this choice:
- Ecological relevance
- Susceptibility to known or potential stressors
- Relevance to management goals
The challenge is to find ecological values that are scientifically rigorous and are also recognized as valuable by risk managers and the public. Possible successful examples include:
- Endangered species or ecosystems
- Commercially or recreationally important species
- Ecosystem functions or services such as food supply, flood control, or nutrient cycling
- Aesthetic values such as clean air in national parks
- Existence of charismatic species such as eagles or whales
Once assessment endpoints are chosen, a conceptual model is developed to provide a visual representation (a map, flow chart, or schematic) of hypothesized relationships between ecological entities and the stressors to which they may be exposed, accompanied by a written description of this process and of the risk questions. These models include information about:
- Source
- Stressors
- Receptors
- Potential exposure
- Predicted effects on an ecological entity (the assessment endpoint)