Author(s): Rui Zhang; Shuichi Kure; Guanzhen Bian; Bambang Adhi Priyambodho
Linked Author(s):
Keywords: Itasenpara; Water quality; Rainfall runoff simulation; Moo River; Oyabe River
Abstract: Acheilognathus longipinnis is called Itasenpara in Japan. Itasenpara is a typical plankton feeding cyprinid that is one of endemic species in Japan. Itasenpara was found in Yodogawa River water system of Osaka Prefecture, the Nobi Plain in Gifu Prefecture and the Himi city of Toyama. However, the number of Itasenpara in Himi city has decreased in resent years. Basic field survey of water quality and river bed materials to eva luate the causes of the reduction of Itasenpara in Moo River water system and Busshoji River system in Himi city were conducted in this study. Also, a rainfall runoff model was applied to the target rivers to evaluate the impact of the historical flood disturbance and future climate change on Itasenpara. According to the results of the survey, the DO, BOD, T-N and chlorophyll a of the target rivers are within the index range of normal life of the carp family. There was no relationship between the reduction of Itasenpara and water quality of the target rivers. The riverbed composition in the middle and lower reaches of the Busshoji River is likely to be unsuitable for freshwater bivalve molluscs that prefer more sand than gravel for living places. As the result of hydrological simulations, it was found that the applied model can reproduce the flood situation in the target rives reasonably well. It should be emphasized that the snow melting in February is a key point for the habitat evaluation of Itasenpara because they require the low water temperature below 5 degree Celsius to survive.
Year: 2020