自然産卵箇所におけるサケ卵の発眼期の生卵率と水質指標等の関連分析

抄録

The importance of wild salmon have been reviewed for species diversity. The river environment in the salmon spawning area is not uniform. Water temperature, water quality, riverbed material, etc. of the riverbed differ depending on the difference of the channel, such as the main channel and the subchannel created by the formation of sandbar. In order to effectively promote conservation and regeneration measures of the spawning bed environment, it is effective to analyze the difference in survival rate to hatching of salmon eggs due to differences in river environments. In this study, as a first step to clarify the relationship between the survival rate to hatching and the environment in the spawning bed, we investigated and analyzed the relationship between the survival rate of salmon eggs up to the eyed-egg stage and the water quality. As a result, it was found that the low dissolved oxygen concentration was likely to have caused the decrease in survival rate up to the eyed-egg stage.