EXAMINATION OF CONTROL OF SUITABLE AREA OF OIKAWA, ZACCO PLATYPUS, IN POOL-AND-WEIR FISHWAY WITH PARTITION

Abstract

 It is important to keep suitable area for fish in pool-and-weir fishway to make the migration rates high. In this study, the control of the suitable area was tried by installation of partition with various positions in pool-and-weir fishway. The migration rates of oikawa (Zacco Platypus) were obtained with the aid of two sets of digital video cameras. It was found that the migration rates of oikawa take the high value by installation of partition to an area between upstream side notch and downstream one. This is because the suitable area of oikawa was moved to the upstream side of partition from the middle part of the pool, and the migration from the slow flow area was induced.