Potential and Pitfalls of Using Cutthroat Trout as an Indicator of Headwater Watershed Condition

Three Upper Willamette River watershed councils (Marys, Luckiamute and Long Tom) joined together with Bonneville Environmental Foundation and other partners to explore the potential of using coastal cutthroat trout Oncorhynchus clarki clarki as an indicator of aquatic habitat condition and restoration success.  The group conducted rolling interviews with regional experts, using a common survey designed to probe the opportunities and limitations of using relative abundance and distribution data to inform restoration strategies and evaluate outcomes.  This synthesis of expert guidance will set the bounds on the appropriate use of cutthroat trout data and what practical tools are most effective in collecting cutthroat relative abundance and distribution data.  A notable finding to date is the geographic variability in cutthroat trout limiting factors, and thus the need for caution in interpretation of cutthroat trout distribution and relative abundance patterns for restoration action planning.  The lack of a single controlling factor leaves ample room for false conclusions regarding habitat condition based on observed patterns of cutthroat abundance.  Our next steps are to refine our conceptual model regarding cutthroat-habitat relationships in the western Willamette Valley, refine our restoration questions, and determine what kind of cutthroat data over what extent would be most expedient for restoration planning and evaluation.