Salmon habitat restoration: Are we putting the right types of projects in the right watersheds?

Background/Question/Methods

Throughout the Pacific Northwest, habitat degradation has been cited as a factor contributing to the decline of Pacific Salmon. With many Evolutionarily Significant Units(ESU) of Pacific salmonids listed under the Endangered Species Act(ESA), habitat restoration is widely used in hopes of increasing salmon numbers with billions of dollars spent on habitat to date. Yet, studies suggest that projects meant to restore freshwater habitat do not always take into account local ecological concerns or impairments. Over 10 years after the majority of salmon ESA listings, we now have the datasets required to spatially compare whether restoration projects match documented ecological needs at the scale of individual populations within an ESU. We use the Salmon Habitat and Project Evaluator (SHAPE) metric as a way of measuring the appropriateness of projects implemented within a watershed for all populations with completed recovery plans or assessments in Washington, Oregon and Idaho. This method provides an objective way to retrospectively assess restoration types and placement, evaluate the appropriateness of proposed projects based on documented ecological concerns, and support recovery plan evaluation.

Results/Conclusions

Over 45,000 restoration project worksites completed between 1980 and 2008 were evaluated across the ranges of ESA listed chum, coho, steelhead and Chinook salmon. At the species level, 70-80% of project types matched a known ecological need, while 75-90% of ecological concerns identified in recovery plans matched at least one project. For example, if a recovery plan reports the lack of large woody debris as an ecological concern, a project adding instream woody debris would remedy this, thus a match. SHAPE scores ranged from .5 (Chinook) to .8 (chum) with 1 being a perfect project/ ecological concern match. As this is a retrospective analysis, most recovery plans were completed too recently to have to guided project type choice in this dataset, however our results can be used as a baseline moving forward, and projects post-recovery plan completion can be evaluated in the future. Our results support the idea that in many cases the right types of projects are being placed but our analysis is also at this coarse scale. Socio-economic factors likely also play a significant role in project placement. This method can and will be used to look at population level differences within an ESU for a given species to help design future project placement, and help funders to prioritize or target specific types of restoration that are underutilized based on need.