Long-Term Monitoring of the Aquatic Animals in a Water-Purification Drainage Channel Improved by the National Irrigation and Drainage Project

— Effects of the environmentally sound irrigation and drainage project in the Konsen area, eastern Hokkaido, Japan —

Abstract

From 2005 to 2019, we conducted a survey of aquatic habitats in cooperation with a local elementary school in the Konsen area, eastern Hokkaido, Japan, in which a drainage channel and a related pond were constructed as part of the environmentally sound irrigation and drainage project. In the survey, we identified a total of 11 families and 18 species of aquatic animals: 7 families and 14 species of fishes, 3 families and 3 species of crustaceans, and 1 family and 1 species of amphibians, including several species that were listed either in the Ministry of the Environment or the Hokkaido Red List. Certain rare species such as Pungitius tymensis, Lefua costata nikkonis, and Phoxinus percnurus sachalinensis, whose habitats have decreased due to the development of the virgin wetlands, and whose populations are fragmented and extinct, were confirmed at high frequency. It was presumed that the newly constructed facility functioned as a habitat for the rare creatures that originally lived in the region.