二級河川板櫃川を対象とした魚類の生息場所の日変化および季節変化の調査

摘要

It is important to make clear the fish habitat quality of daily and seasonal changes in rivers, because this information is useful to make an improvement river plan considering the fish environment. Such field surveys have not been conducted so much, due to its difficulty. Recently, a new survey technique of fish habitat quality using model submarine and small wireless camera was suggested. In this study, field surveys of fish habitat quality of daily and seasonal changes were conducted through one year in Itabitsugawa river which belongs to class B river. It was found that Zacco platypus eats the attached algae on rocks in riffles from morning to early afternoon in September. Zacco temminckii is pushed out from riffles to pools at this time. After eating, the occupied area of both fish is swapped. Through the year, Zacco platypus and Zacco temminckii occupies riffles and pools at early afternoon, respectively.