Monitoring Marine Debris Using Disposable Lighters as an Indicator

Sources of marine debris that had drifted ashore in Japan were investigated using a specific indicator item. Disposable lighters were chosen as an indicator because the discharge area and location can be distinguished from the print on the surface of the tank and the punch mark on the bottom. In one year, 6609 lighters were collected from 120 beaches by nation-wide beach combers. Chinese lighters accounted for over half of those collected in coastal areas from Yonaguni Island (Okinawa) to Yaku Island (Kagoshima), and they accounted for about 10-20% of the lighters found along the coast of the Japan Sea from Kyushu to Yamagata. Korean lighters accounted for 10% in the coastal areas from Okinawa to west of Kyushu, but accounted for over half of the lighters found on the coast of the Japan Sea from Shimane to Fukui. Japanese lighters almost filled in the coasts of Seto Inland Sea and Tokyo Bay, and at the Pacific coast of the north from Shikoku. Lighters from other countries were found in the coastal areas of Zhejiang and Guangdong (in China), and across Taiwan and Korea. By pinpointing one item various connections could be made between discharge and flow.