Occupancy and Distribution of Coastal Cutthroat Trout in the Lower Columbia River

Declines in coastal cutthroat trout distribution, abundance and life history diversity have been documented across the range of the species in recent decades.  However, a lack of available quantitative data has underscored the need to better understand the current and potential distribution of coastal cutthroat trout.  Since 2008, the U.S. Fish and Wildlife Service – Columbia River Fisheries Program Office has been implementing an ongoing project in the lower Columbia River basin to quantify occupancy and distribution of coastal cutthroat trout and determine habitat parameters that predict potential distribution.  Achieving the objectives of the project relies on the development and implementation of a sample design that utilizes minimal available resources (e.g., funding, personnel).  The chosen approach meets this goal and generally follows the standardized methodology developed for quantifying bull trout occupancy and distribution.  Similarly, this chosen approach could be standardized to detect spatial and temporal trends in occupancy and distribution of coastal cutthroat trout.  Results to date for coastal cutthroat trout occupancy and distribution will be presented from various watersheds in the lower Columbia River basin.  Ultimately, the current known occupancy and distribution information for the species will feed into status assessments and conservation planning.  An approach utilizing minimal resources will be necessary to improve that state of information.