- 琉球大学理工学部紀要 理学篇 (ISSN:03874281)
- no.23, pp.p51-56, 1977-03
Among the islands of the Ryukyus, dolphin driving fishery is operated only on the Nago beach of Okinawa Island. Strange enough, the habit of eating dolphin meat is rarely seen on the other islands. The fishing there has been done not only for profit but a festival related closely to the native religion. Anyone who had helped fishing was given free share of the harvest as a blessing of God. After a blocade of the new port of Nago was built, dolphin fishing there is not so successful as before. What is worse than that, lately, fishermen sometimes experience during a driving an nuisance approach of leisure boats, on which people come to see the sight for pleasure, and disturb the control of the driving group and caused escape of many dolphins. Recently, in the waters around Iheya and Izena Islands, some fishermen began to do small scale dolphin catch with hand harpoons sporadically in the need of making up their poor harvest. Dolphin meat is sold roughly US$ 1.5-2.5 per kg., and the meat is said to be a good medicine for neuralgia. The number of catch in Nago in the past seventeen years is indicated in Table 1. Usually, a little more or less than 100 animals were caught at a time of driving. The number of catch shows decrease since 1971 when the port of Nago was built and the sandy beach was destroied. Season of fishing is show in the same table, fishing is most prosperous in March. In this season, groups of dolphin are migrating to the north. The monthly water and air temperature in Okinawa is shown in Fig.2. The species of dolphins caught in Okinawa concentrate on the pilot whale, Globicephala macrorhyncha. Animals of Trusiops spp. have been caught sporadically, in 1971 Pseudorca crassidens were found among a school of pilot whales. In January 1976, a school of Steno bredanensis was caught; this is the first record of this specis recognized in Okinawa. Topographical feature of the coast is that the reef barrier is cut open at that place and 200 meter conter depth of water passage streach to the Nago bay, which leads dolphins to come into the bay. Besides, Sepioteuthis lessoniana, a favorite food of dolphins, are living in the depth to invite dolphins. Fishermen's hooked fish are often pursued and bit by dolphins, species of those mischievous dolphins are likely to be of genus Tursiops and Pseudorca. Above explanation was presented at the meeting of Scientific committee of the International Whaling Commission in June 1976.