US EPA

6445254 

Journal Article 

Present status of eel research in Japan 

Kaneko, Y 

2000 

55-56 

Commercial eel culture is depending entirely on the supply of glass eel caught in coastal waters. In recent 30 years, the glass eel catch in Japan showed a drastic decrease. The development of artificial seed production is progressing to secure stable eel culture production but, it has not been successful, yet. Thus, it is an urgent issue to assess, control and protect the eel stocks in freshwater habitats to increase the escapement of silver eel. So far, ecological research for eel stock management has been little and sporadic in Japan, while reproductive physiology for artificial maturation and seed production was popular. Thereupon, Fisheries Agency initiated the project for surveying present status of the Japanese eel (Anguilla japonica) in freshwater and development of the stock management systems for a 5 years plan that started from 1999. Japan Fisheries Resource Conservation Association (JFRCA) entrusted by the Agency is implementing the project cooperating with Ocean Research Institute of The University of Tokyo, Prefectural Fisheries Experimental Stations and the eel culture co-operative associations. The project is consisting of three research items as follows: 1) Eel researches in freshwater - Collection of biological and environmental informations on the yellow eel and development of the long-term monitoring systems for their stock dynamics; Excavation of the old catch statistics; Analysis of the catch statistics obtained; Biological studies (ex. age/ maturity/ species identification); Environmental research (ex. temperature/ salinity) More than 15 rivers or lakes in 9 prefectures around the Pacific coast are the research fields which are the major eel producing districts. 2) Stock management systems of glass eels - Development of the appropriate management method of glass eel catches, to sustain river stocks; Monitoring and data analysis of the glass eel catches; Examination of the effect of the glass eel catch on wild stocks. The catch is controlled and carried out systematically in Miyazaki Prefecture. 3) Development of the eel stocking methods - Release and recapture experiments of tagged or fin clipped eels; Study on migration route of silver eel using acoustic tracking at estuary. To evaluate the output from the project, the examination committee was established with JFRCA acting as the secretariat to reflect the opinions from various sectors and also, to discuss technical problems. 

; Stocking (organisms); Aquaculture development; Seed production; Fish culture; Rivers; catches; maturity; Physiology; Temperature; committees; Coastal waters; Aquaculture; surveying; Salinity; Environmental information; Lakes; acoustic tracking; Oceans; Fisheries; Conservation; sustainability; Silver; fishery resources; Anguilla japonica; Marine/