Two distinct runs of Coast Coho – or “Evolutionarily Significant Units” (ESU’s) – call the Oregon coast home. The first, the “Oregon Coast (OC) Coho” is comprised of 21 independent populations that spawn and rear in watersheds from the Columbia River south to Cape Blanco. The second ESU, the “Southern Oregon Northern California Coast (SONCC) Coho” includes seven independent populations in Oregon, which spawn and rear in watersheds from the Elk River (near Cape Blanco) south to the California border. (There are an additional 23 SONCC populations in California considered independent or potentially independent).
Both of these ESUs are listed as “threatened” under the Endangered Species Act, and NOAA completed recovery plans for SONCC and OC coho in 2014 and 2016, respectively. As detailed in the two plans, Coast Coho salmon are primarily affected by stressors that reduce the quantity and quality of floodplain and channel structure and degrade water quality, creating key limitations to their rearing and spawning habitats. Reviews by NOAA biological review teams in 2011 and 2015 found that the long-term decline in coho salmon productivity reflected deteriorating conditions in freshwater habitat, and that the remaining habitat may not be high enough quality to sustain the species’ productivity during cycles of poor ocean conditions (NWFSC 2015; Stout et al. 2012).
Watershed restoration called for in the federal recovery plans is undertaken largely by local watershed groups, government agencies, and NGOs that partner with public and private landowners (both industrial and non-industrial) to implement projects on the ground. The capacity of both the project managers and the landowners is limited relative to the size of the watersheds and the magnitude of the habitat degradation, which began well over a century ago. Accordingly, it is imperative that the limited federal, state, and private funds committed to watershed restoration are spent strategically and on the highest impact projects. The plans generated by the Coast Coho Partnership seek to ensure this occurs.