Creative enhancement of fish habitat based on fish school and microorganism behavior in eutrophic dam

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(1) Migrating behavior of juvenile fishes in stream-type fishways This section is intended estimate upstream migration behavior for juvenile fishes in Denil, Steeppass, modified Larinier Pass and boulder-mounted slope fishways. Experimental facilities have used four kinds of fishways in the hydraulic laboratory and as juvenile fishes : ayu (plecogllossus altivelis), goby (chaenogobius urotaenia), char (Salmo (Oncorhynchus) masou marcostamus), trout (Salmo (Oncorhynchus) masou masou, Salmo (Oncorhynchus) masou marcostomus). As a result, juvenile ayu migrated the regions where generated weak turbulence, especially they went upstream along side walls in constant slope fishway. Also, as for the juvenile trout and char, they can select the routes according to their individual swimming potential, as cross sectional velocity distributions in boulder-mounted slope fishways are wide range. Moreover, it is necessary to provide the resting area for the bottom fish such as goby.(2) Microorganism b … More ehavior in eutrophic dams This section is intended to estimate the structural analysis of bacterial phase in river water and mud at Nagara estuary barrage and aerobic submerged biofilter in sewage plant at Gifu National College of Technology. The bacterial phase have a variety of quinones such as ubiquinone (UQ), menaquinone (MK) and prastoquinone (PQ). In the case of aerobic submerged biofilter in sewage plant, the bacterial phase of menaquinone (MK) dominated. Prastoquinone (PQ) according to photosynthesis action observed in river water and mud at Nagara estuary barrage. The water quality and organism index such as COD, chlorophyl-a, ignition loss and diameter of substance are proportional to quinone concentration in connection with bacterial amounts.(3) Creative enhancement of fish habitat In recent years, the importance of vegetation in rivers and dams in recognized not only then viewpoint of flow resistance but also from the ecological viewpoint as soft interface. Hydraulic action on vegetation, whether limited to banks and in-stream, controls, a major source of carbon to aquatic systems. Stream that are rich in carbon detritus provide an appropriate base for the aquatic food chain. To be effective detrital delivery from riparian zones should be designed at the "reach" scale or larger. Less