Author(s): Makoto Hyodo; Shinji Tkahashi; Takemon Yasuhiro; Tetsuya Sumi
Linked Author(s): Tetsuya Sumi
Keywords: No Keywords
Abstract: The lower reach of the Tenryu River in Japan is a gravel braided river under high disturbance regimes. In the lower reach, prolong turbidity has affected water quality and the degradation process has occurred over years due to several hydropower dams constructed at the upstream reach, negatively affecting the suitable spawning redds for Ayufish (Scorpaeniformes, Plecoglossidae, Plecoglossus altivelis altivelis). Our recent study revealed the importance of dynamic physical indicators for the spawning redds such as: the location used to be a channel, loose riverbed sediment is created by deposition, and up-welling flows with low turbidity and adequate DO, etc. This study introduces a series of restoration project carried out in the Tenryu River in 2014 to 2018 and verified the effectiveness of our approaches to creating spawning redds of Ayufish through field surveys conducted before and after the restoration.