Japanese Whaling and Other Cetacean Fisheries (10 pp)

BACKGROUND, AIM AND SCOPE: Discussions on management of whales and whaling are factually monopolized by the International Whaling Commission (IWC), resulting in a limitation of information flow to outside communities. With an aim to improve the situation, this article briefly reviews whaling and dolphin/porpoise fisheries in Japan, which is recognized to be the world largest cetacean exploitation. MAIN FEATURES: The Japanese government grants an annual take of 22,647 cetaceans of 15 species for scientific whaling and various kinds of active dolphin/porpoise fisheries by the nationals. Further, over 100 baleen whales and numerous small cetaceans are taken in passive net fisheries. They are used mostly for human consumption and some for aquarium display. RESULTS: Sustainability of the take is not evident and some populations have shown a historical decline. The Japanese program of scientific whaling has been reviewed by IWC and its Scientific Committee (SC), although they have arrived at no consensus. DISCUSSION: The current scientific whaling program invites arguments from the view points of science as well as concerning the ethics of scientists, economy, and interpretation of the International Convention for Regulation of Whaling (ICRW) of 1946. The scientific whaling and other Japanese cetacean fisheries are benefited from nationalistic public attitude, and ambiguity and weakness of the ICRW. CONCLUSIONS: Japanese cetacean harvest will continue supported by domestic demand for whale products as long as the proceeds can sustain the operation, even with criticisms from outside communities. RECOMMENDATIONS AND PERSPECTIVES: For safe management of small cetaceans exploited by Japan, studies are urgent on the population structure, abundance and validity of catch statistics. The results should be open to scientific communities.     

Aquatic Resource Conservation. The first Yangtze finless porpoise successfully born in captivity (4 pp)

Background As the sole freshwater subspecies of finless porpoise (Neophocaena phocaenoides), the Yangtze finless porpoise (N. p. asiaeorientalis) lives only in the middle and lower reaches of the Yangtze River and its appended Poyang and Dongting Lakes. As a result of human activity on the river, including over and illegal fishing, pollution, transportation and dam construction, the population of Yangtze finless porpoises has been steadily and rapidly decreasing during the past several decades, which leads the animal to be endangered. Methods For saving this unique animal from extinction, three corresponding measures, in situ conservation, ex situ conservation, and intensifying breeding research in captivity, were proposed and have been implemented since the 1980s. Results After successfully rearing the animals in captivity for almost nine years, the first Yangtze finless porpoise was successfully born in captivity on July 5, 2005. The calf is male, with a body length of 69cm. This is the first freshwater cetacean ever born in captivity. Conclusion The successful birth of this calf confirms that it is possible to breed the Yangtze finless porpoise in captivity. Furthermore, this will greatly benefit the conservation efforts, and also greatly bolster our on-going efforts to study the reproductivebiology of these animals. Recommendation More studies and efforts are expected to establish a sustainable, captive colony of the Yangtze finless porpoise, which will not only greatly expand our knowledge about the reproduction biology of this animal, but also help to redeem the wild population through a careful yearly 'soft releasing' process.     

渤海江豚体内汞的初步研究

１９９０年采于辽东湾的１０头江豚标本，分别测定了其皮肤、骨骼、肌肉、肝脏、肺、肾、心、胃、肠、胰、脾、肾上腺及生殖腺等１３种组织中汞的含量。其主要累积于肝、脾、肾。约在７龄以前，各组织中汞的浓度有随年龄、体长、体重的增加而有增加的趋势。     

长江江豚的交配行为和摄食行为的研究

１９９２年４月～１９９３年２月，在铜陵白豚养护场，对饲养条件下的４头长江江豚的交配行为和摄食行为进行了观察，较全面地描述和分析了江豚的交配、摄食行为模式，根据观察记录，长江江豚交配行为发生有一定的时间顺序，其交配期在３～６月；江豚背部小齿在交配活动中具有重要的生物学意义。江豚摄食的欲求行为有较强的驱动力，饥饿时常吞食异物。本研究不仅可用于江豚的保护和管理，亦可探索有效保护白豚的途径。