open access

https://hdl.handle.net/2115/42949

A challenge to dam improvement for the protection of both salmon and human livelihood in Shiretoko, Japan's third Natural Heritage Site

英語

Restoration

2010-01

Springer Japan

Landscape and Ecological Engineering

6(1)

143-152

The Shiretoko Peninsula was placed on the World Heritage List in July 2005 as Japan's third Natural Heritage Site, being valued for its unique ecosystems formed by the interaction between marine and terrestrial environments. Prior to its listing, however, the International Union for Conservation of Nature and Natural Resources requested the development of measures to allow for the free movement of salmonids through the nominated area via artificial in-stream structures. This report introduces a pioneering effort to modify check dams in order to improve ecosystem linkages. The River Construction Working Group has intensively discussed and implemented restoration projects for three years, and the results have been monitored after implementation. Of 44 streams within the Shiretoko World Natural Heritage Site, 14 streams have had one or more in-stream structure(s) built. A total of 123 structures, mainly soil conservation dams, are distributed sporadically in these streams. Following assessment, the Working Group concluded that it would be reasonable to modify 31 structures in 5 streams, including 18 structures that were to be modified before listing. The most suitable design that met local stream conditions was selected, after accounting for salmon passage, adverse impacts on stream environments above and below the construction sites and on fishing grounds, efficiency of construction and ease of post-modification maintenance. Working in cooperation among the group members and parties concerned, we succeeded in restoring salmonids' upstream runs and extending their spawning habitat in streams above some of the dams, while keeping the disaster prevention function of the dams intact.

学術雑誌論文

Accepted Manuscript

The original publication is available at www.springerlink.com

1860-1871