| 英文摘要 |
Japanese eel (Anguilla japonica) is one of the most important culture species in Taiwan. The fluctuation of elvers catch in recent years has not only suffered the income of capture fishers but also the culture industry itself. In this study, we analyze AVHRR sea surface temperature images and eel elvers fishery data to find out the relationship between Kuroshio branch current and abundance of elver immigrated in Lin-Yuan, Southern Taiwan. The shortest distances between Kuroshio branch edge, detected from AVHRR data by edge detection technique, and the Lin-Yuan were used as the forcing indices of passive transport of eel elver. We observed successive series of such distances and its interaction with monthly SST images and catch of elvers. We found that elvers catch was higher while the distance, ranging from 0.5 to 89.1 nautical miles, were shorten. It suggests that more elvers will be transported into the Lin-Yuan, if Kuroshio branch current moves closer to the Lin-Yuan. We also examed the variability of the two variables, the distance and catch during Taiwan El Nino and normal periods. The results indicated that the shorter distances during Taiwan El Nino periods implying closer approaching of the Kuroshio branch edge would result in high successful transport of elvers into the Lin-Yuan. |
