Oregon Coastal Salmon Restoration Initiative Chapter 3 Risk Agents Responsible for the Decline of Oregon Coastal Coho Salmon Introduction Salmon have declined to a small fraction of their historic abundance in Oregon.
Society recognizes the immediate crisis, namely, too few salmon.
Damming streams Historic efforts to remove wood from streams Natural cyclic variation in weather and ocean productivity Risk Agents Risk agents consist of natural processes or human activities that place sustainability of salmon at risk. Fishing, artificial propagation, alteration of spawning and rearing habitats, and introduction of exotic species are examples of risk agents related to human activities. Some risk agents are natural and would exist if humans were not present in the region. Volcanic eruptions, earthquakes, landslides, fire, ice ages, and the like, are also natural risk agents that have and will affect the sustainability of salmon populations and species. Other risk agents are largely related to the activities of people.