Using Qualitative Risk Evaluations to Prioritize Resource Assessment Activities for Fraser River Sockeye

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Abstract

Management of Fraser River sockeye salmon is evolving towards an inclusive and transparent process. An important part of this evolution is to establish clear guidelines for developing assessment plans, interpreting the collected information, and sharing scientific advice. As a first step, this paper proposes a framework for risk-based rapid appraisals of Fraser River sockeye to identify major threats and information gaps.

We establish a comprehensive hierarchy of criteria and specify risk-based qualitative scales for evaluating performance relative to each of the criteria. Risk evaluations incorporate the two dimensions of severity (i.e. judging current status) and uncertainty (i.e. judging quality of information) to delineate five distinct risk categories:

  • insufficient information
  • status probably poor, but little information
  • status poor, high confidence
  • status probably good, high uncertainty
  • status good, high confidence.

This research document illustrates the proposed framework, using rapid appraisals we completed for 36 conservation units based on information available at this time. Preliminary risk evaluations proved useful for identifying information gaps, sorting sockeye stocks into risk categories, establishing risk profiles for each management grouping of Fraser sockeye, and comparing those risk profiles to past patterns of assessment coverage. For example, conservation units can be ranked based on a combination of status, vulnerability, and current human impacts. Stuart-EStu and Cultus-L emerge as the highest priority, because the risk-based evaluations indicate very poor status. Next in the priority list are CUs with poor status, and either high levels of harvest mortality (Trembleur/Takla-S) or high vulnerability (Kamloops-L).

Additional work will be necessary before the proposed framework can be fully implemented. Specifically, we recommend that DFO:

  • Establish an expert panel to complete risk-based rapid appraisals
  • Expand the inventory of risks and information gaps
  • Complete formal assessments of priority CUs
  • Build a system model for evaluating alternative harvest and assessment strategies
  • Develop integrated assessment approaches