Thursday September 8, 2022
Oregon Department of Fish and Wildlife —
Why are there dead salmon in the river? If you live close to a river or stream in the Willamette Valley, you might come across salmon carcasses or see ODFW staff and volunteers slinging carcasses into the water during September and October.
In September, salmon will begin the end of their life’s journey in Willamette Valley rivers as they gather to spawn and die. Historically, thousands of adult salmon spawned and died in these rivers and streams, supplying essential nutrients to fuel the stream ecosystem. The salmon also feed bears, otters, raccoons, skunks, turkey vultures, eagles, hawks, ravens, and other animals as well as fertilize trees and vegetation along the stream banks.
September is also when ODFW hatcheries spawn salmon for future smolt releases. After the salmon are spawned, ODFW staff and volunteers distribute the salmon carcasses from the hatcheries to rivers and streams throughout the Willamette Valley for stream nutrient enrichment.
Hatchery salmon carcasses distributed to rivers and streams around Oregon enrich the food web of stream systems. By returning hatchery brood salmon carcasses to local rivers and streams, their bodies can provide nutrients for algae and other aquatic plants, as well as food for aquatic invertebrates that in turn provide forage for larger species such as fish.