Knowles Creek
Coho salmon. Photo courtesy NOAA Fisheries National Marine Fisheries Service.
JB: This is Earth and Sky with more about wild coho salmon in Knowles Creek, a tributary of Oregon’s Siuslaw River.
DB: A century ago, as many 1/2 million salmon migrated here from the sea. But populations in the Siuslaw are down to about 1% of that. Charley Dewberry is a restoration ecologist based in Portland, Oregon – part of the Knowles Creek Restoration Project.
Charley Dewberry: We really need to be looking, not only at what’s going on in the stream channel, but also what’s going on upslope. And, one of the things that was very clear to us early was that all parts of the landscape aren’t equal for salmon.
JB: During winter floods, coho habitat becomes vulnerable to sudden bursts of water caused when pockets of debris collapse. Fallen logs from large, old growth trees help form a shield to protect salmon habitat. That’s why, Dewberry said, maintenance outside the stream – stormproofing roads to reduce debris flows and preserving old growth forest – is as important as work done instream.
DB: So far, the restoration efforts are working. Dewberry said salmon in Knowles Creek are up from a record low of 10 in 1992 to about 4,000 – considered the minimum needed for a sustainable population. Thanks to the U.S. Forest Service and to the National Fish and Wildlife Foundation – supporting the conservation of native fish, wildlife, plants and their habitats. We’re Block and Byrd for Earth and Sky.
The following person was interviewed for today’s program. Our thanks to:
Charles Dewberry
Restoration Ecologist
Ecotrust
Portland, OR
Websites:
Fact Sheets – Coho Salmon (NOAA Fisheries – National Marine Fisheries Service)
ADF&G Wildlife Notebook Series (The State of Alaska)
BLN Builds Cascades on Siuslaw – The Register-Guard ( Eugene School District J4)
Science Alone Can’t Save the Salmon – ENN (February 22,2000)
ENN
Watershed work turning coho habitat around – The Register-Guard ( Eugene School District J4)
Office of Protected Resources (NOAA Fisheries – National Marine Fisheries Service)
Riding the Silver Cycle (Pacific States Marine Fisheries Commission)
California Partners for Fish and Wildlife (US Fish and Wildlife Service)
Additional Teacher Resources
Eco-trust, ecotrust.com, Concepts in Action: Concepts in Action: Restoring Knowles Creek
Historical sources suggest that 75,000 to 100,000 coho salmon smolts migrated to the ocean from Knowles Creek spawning gravels each year around the turn of the 20th century. A hundred years later, few than 1,700 smolts were making that journey. What had been done to make the creek so hostile to salmon survival? Could that be reversed? This article tackles these questions as well as explores the current status of coho salmon in Knowles Creek.
USDA Forest Service, Siuslaw National Forest, Monitoring Report: Siuslaw National Forest, Forest Plan Monitoring
Knowles Creek is a tributary of the lower Siuslaw River. Historical sources suggest that in-migration of spawning coho surpassed 400,000 in Knowles Creek. A hundred years later, fewer than 1,700 smolts were starting that same journey. This article discusses how in the mid 1980s when watershed and fisheries professionals realized that the stream was out of balance, an unprecedented agreement between agencies, environmentalists and industrial foresters was formed, and the resulting effects this partnership had on the watershed and the coho salmon populations.
Tree Dictionary: What We Know About Large Trees That Fall Into Streams and Rivers
The most productive habitats for salmonid fish are small streams associated with mature and old-growth coniferous forests where large organic debris and fallen trees greatly influence the physical and biological characteristics of such streams. This 62 page report covers how debris and fallen trees effect salmon populations.
