Release of eels What is the effective release method? Report by the research group on July 30, 4:05
The research group, which has been commissioned by the Fisheries Agency, has compiled a report on an effective eel release method for eel release nationwide for the recovery of Japanese eel resources.
Japanese eels release farmed eels all over the country every year because of the recovery of resources by fisheries cooperatives in various regions, but the ecology of eels is a mystery and it is not clear how effective they are.
The research groups of the Fisheries Research and Education Organization and Chuo University, which have been conducting research on this matter under the commission of the Fisheries Agency, have compiled a report.
According to that, when we examined the degree of growth by releasing cultured eels in four rivers nationwide such as Shizuoka and Aomori prefectures, the weight of the eels released in rivers with few natural eels increased. , On the contrary, in the river with many natural eels, it was found that many eels lost weight. According to the research team, the released eels may have lost the competition with natural eels.
In addition, although it is said that domestic eels often release mature eels, the report pointed out that it is effective to release small eels up to a few grams based on overseas studies.
Associate Professor Kenzo Kaifu of Chuo University, who conducted the survey, said, “It is becoming clear that large eels cannot be expected to survive even if they are released. In addition, because there is a possibility that they will compete with natural eels, there are many places where there are many natural eels. So, isn't it important to recover the environment rather than release it?"