Utilization of a spatial decision-support tool for the restoration of Chinook salmon in the Columbia River

Abstract

Managers, policy-makers, and practitioners often utilize spatially-explicit decision-support tools for assistance and guidance in managing highly dynamic and spatially diverse environmental systems. Here I explore the use of the Landscape Planning Framework as an example of a decision-support tool that supports a systematic, landscape-based approach to fish habitat management in the Columbia River estuary. I identified the importance of landscape features or habitat attributes to the growth and survival of ocean-type, juvenile Chinook salmon (<italic>Oncorhynchus tshawytscha</italic>) and ranked them each on a scale from 1 (greatest importance) to 12 (least importance). I used these rankings to test the relative function of aquatic channel landscape features in identifying areas for potential restoration to benefit salmon stocks that rear in the estuary. In a series of five spatial trials I estimated the cumulative contribution of potential salmon habitat restoration areas by summing different combinations of rankings and grouping the ranking totals in equal-interval low (lowest potential restoration function), medium, and high (highest potential restoration function) categories. I calculated the abundance, length, area, and edge density of equal-interval categories, analyzed in the form of polygon layers, for purposes of comparison. Regardless of the combination of rankings and grouping totals, the equal-interval high category returned the lowest metric values. My results indicate that the set of sites characterized as areas of high possible restoration value is most constrained in the equal-interval high category. As a relatively new decision-support tool, the Landscape Planning Framework serves as a useful instrument for efficient management of an estuarine landscape to more effectively support its inhabitants.