Working for Fish in Alaska's Tongass
By restoring salmon streams in the Tongass National Forest, The Nature Conservancy is helping to keep salmon runs healthy for nature and people.Watch Video
“We’re very fortunate at Twelvemile Creek. We still have a healthy salmon population in the creek,” says Brian Barr, a Tongass National Forest hydrologist. “We’re not working to bring back a decimated population. What we’re doing is we’re trying to preserve a population.”
Much of the logging and road building in the Twelvemile Creek watershed occurred under less protective regulations of the 1960s and 1970s. As of 2006, about 6,000 acres, or 47 percent, of the watershed was forested. This includes more than 90 percent of the forest along salmon streams.
While Twelvemile Creek currently supports good salmon populations, the watershed is at a critical time in its history due to the continued decline of in-stream large woody debris (think big trees) and the fish habitat it creates.
Logging that occurred along streambanks took away future sources of large wood for the stream, and the remaining instream wood is rapidly decaying. The result is a stream with unstable banks and less large wood, leading to fewer pools, vulnerable spawning gravels and wide, shallow stream channels. These conditions reduce habitat for rearing salmon, which leads to a decline in spawning success.
In addition, some roads in the Twelvemile Creek basin have disrupted natural stream flows, further reducing the quality of fish habitat.
Farther upstream, much of the second-growth forest is blocking sunlight from reaching the forest floor. If left untreated, wildlife food plants such as blueberry shrubs won’t have enough sunlight to sustain them. Action to restore light to the forest floor now can ensure food for wildlife such as Sitka black-tailed deer.
The project to restore Twelvemile Creek is a partnership of the U.S. Forest Service, National Forest Foundation and The Nature Conservancy.
Quick Facts on the 2012-2013 Twelvemile Creek Restoration Project:
- Placed more than 600 logs in a section of the stream channel where large woody debris was largely absent or on the decline.
- Thinned 27 acres of streamside forest to promote the growth of bigger bank-stabilizing trees.
- Thinned 530 acres of dense upland second-growth forest.
- Closed five miles of temporary roads.
- Instream work was conducted by operators from Southeast Road Builders, Inc. (2012) and S&S General Contractors, Inc. (2013) using tracked excavators to place the wood and build logjam structures in the stream.