Abstract
Freshwater environments in Hokkaido have been significantly altered by human activities. Restoration work in a channelized reach of the Shakotan River was carried out in 1996. Habitat complexity was increased by the addition of structures to the restored section which replaced a simple stream structure with pools, riffles and runs. More spawners and juveniles were found in the restored reach than in the unimproved control reach. Restoration with log dams and deflectors improved habitat for masu salmon, and is a useful habitat enhancement technique in natural streams. We encourage more programs such as ours where biologists and engineers work together to improve habitat conditions in streams to benefit salmon.
