EFFECTS OF DENSITY OF MESH MAT AND DISCHARGE IN FISH LADDER ON MIGRATION CHARACTERISTIC OF Anguilla japonica

Abstract

 The number of eels is decreased these days. As one of the factors about that, intake facilities and drop works prevent eels from migrating. It is reported that mesh mat is useful for migration of eels. However, there is no research on the proper geometric form for migration of eels. This study is made to evaluate migrating characteristics of eels under the condition that density of mesh mat and discharge in fish ladder are changed. As a result, it was found that migration success rate and void entry rate increased and average migration speed decreased with increacing density of mesh mat regardless of a change of the discharge.