DEVELOPMENT OF THE METHODOLOGY TO UNDERSTAND THE ECOLOGY OF MINKE WHALES USING ENVIRONMENTAL CONTAMINANTS AS CHEMICAL TRACERS

对1981 ~ 1999年和1994 ~ 1998年分别在南大洋和北太平洋采集的约500头和160头小须鲸样品进行了化学分析，结果表明：1）建立了小须鲸各器官组织中有机氯、有机锡和重金属含量的监测系统。这些污染物在小须鲸体内的分布结果表明，鲸脂中有机氯和肝脏中有机锡等重金属可以作为研究小须鲸生态学和生物学的合适组织/器官。2）小须鲸体内有机氯和有毒元素的残留水平因性别、食性和年龄而异，这表明，为了区分小须鲸的种群，有必要对样本进行分类。 ...更多信息 利用重金属和有机氯作为化学示踪剂对鄂霍次克海小须鲸种群进行了分类，结果表明，鄂霍次克海小须鲸种群中DDTs和PCBs的含量显著高于其它海区，Hg的含量显著低于其它海区，Cd的含量显著高于其它海区，HCHs的含量显著低于其它海区，表明前一类群主要分布于南海或日本海/黄海/东海，后一类群是从北太平洋西部迁入的。肝脏中的代谢酶活性表明，在南极小须鲸中，有机氯残留水平低的情况下会诱导CYP 1A，这意味着小须鲸对这些污染物的毒性效应敏感。小须鲸CYP 1A基因的氨基酸序列与北太平洋北方海豚CYP 1A基因的氨基酸序列具有相似性。5）用皮肤和肝脏中的12种微量元素对南小须鲸种群进行主成分分析，结果表明，南极Ⅲ、Ⅳ、Ⅴ区雄性动物的微量元素组成存在显著差异。这些种群似乎与迁徙、繁殖、食性等有关。这种利用动物皮肤中微量元素的方法被证明是一种有效的非捕杀方法，可以阐明小须鲸的生态学和生物学。本研究认为，环境中的有机氯和重金属等化学物质是了解生态环境的有用化学示踪剂，和生理方面的问题还不清楚。少

The minke whale samples including about 500 individuals collected from the Southern Ocean in the period of 1981 to 1999 and about 160 individuals from the North Pacific during 1994 to 1998 under the special permit of Japanese Whale Research Program(JARPA)were employed for chemical analysis and obtained the following results ;1)The analytical systems for monitoring the concentrations of organochlorines, organotins and heavy metals in various organs and tissues of minke whales were examined and constructed. The results of body distribution of these contaminants suggested to use the blubber for organochlorines and the liver for heavy metals including organotins as a proper tissue/organ to elucidate the ecology and biology of minke whales.2)The residue levels of organochlorines and toxic elements were varied according to sex, feeding habit and age, which suggests the necessity of classification of samples in order to discriminate the population of minke whales.3)When estimating the discrim … More ination of population in minke whales of North Pacific using some heavy metals and organochlorines as chemical tracers, the animals from the Sea of Okhotsk were classified into two groups with significantly higher concentrations of DDTs and PCBs and lower concentrations of Hg and with apparently higher concentrations of Cd and lower concentrations on HCHs, suggesting that the former group is principally inhabiting in the Sea or Japan/Yellow Sea/East China Sea and the latter group is immigrated from the western North Pacific.4)The determination of drug-metabolizing enzyme activities in the liver indicated the induction of CYP1A with low residue levels of organochlorines in the Antarctic minke whales, which implies sensitive to the toxic effects of these contaminants in minke whales. The CYP1A genes in minke whales revealed the similarity of amino acid sequences on that genes in Dall's porpoise from the northern North Pacific.5)The attempt to discriminate the population of southern minke whales using 12 trace elements found in skin and liver by the principal component analysis showed the significant difference in the matrix of trace elements among male animals from Area III, IV and V in Antarctic Ocean. These populations seemed to be segregated in association with immigration, reproduction, feeding habit etc. Thisapproach using the trace elements in the skin of animals is evidenced to be an effective non-killing method to elucidate the ecology and biology of minke whales.Considering all these results, the present study concluded that the environmental chemicals such as organochlorines and heavy metals were useful chemical tracers to understand the ecological and physiological aspects of minke whales yet to be known. Less