The harvest of Japanese eel has decreased greatly, and it is pointed out that the effective resource conservation is necessary. For this purpose, knowledge about ecology of Japanese eel, especially the population dynamics is essential, while there remain a huge room to uncover. Since the Japanese eel spawns in Mariana Ridge and is transported by the Kuroshio Current, the Kuroshio is presumably an important factor in the population dynamics.

Here, we studied the impact of the Kuroshio on the annual fluctuation of the glass eel recruitment to Japan. We used the time-series data at 9 prefectures from 1977 to 1997, composed of the CPUE-based recruitment fluctuation as an objective variable, and the Kuroshio transport, the distance from the Kuroshio to the land in front of each prefecture, and distance from the Kuroshio to the land to the west of each prefecture as the explanatory variables. To prevent the spurious correlation, we used the generalized least squares in the framework of the linear mixed effects model. As a result, there was a significant positive correlation with the Kuroshio transport. However, the correlations with these distances were not significant.