Data from: Genetic variation in blue whales in the eastern Pacific: implication for taxonomy and use of common wintering grounds

Many aspects of blue whale biology are but poorly understood. Some of the gaps in our knowledge, such as those regarding their basic taxonomy and seasonal movements, directly affect our ability to monitor and manage blue whale populations. As a step towards filling in some of these gaps, microsatellite and mtDNA sequence analyses were conducted on blue whale samples from the southern hemisphere, the eastern tropical Pacific (ETP), and the northeast Pacific. The results indicate that the ETP is differentially used by blue whales from the northern and southern eastern Pacific, with the former showing stronger affinity to the region off Central America known as the Costa Rican Dome, and the latter favoring the waters of Peru and Ecuador. Although the pattern of genetic variation throughout the southern hemisphere is compatible with the recently proposed subspecies status of Chilean blue whales, some discrepancies remain with published morphological data, and not all blue whales in Chilean waters can be assumed to be of this type. Also, the range of the proposed Chilean subspecies should be extended to the ETP, at least seasonally, and perhaps to the northeast Pacific as well.

蓝鲸生物学的诸多领域迄今仍未得到充分阐明。当前我们在蓝鲸认知上存在诸多空白，例如其基础分类学与季节性移动模式相关的认知缺口，直接制约了我们对蓝鲸种群的监测与管理能力。为填补部分此类认知空白，研究团队针对南半球、东热带太平洋（Eastern Tropical Pacific, 缩写ETP）以及东北太平洋的蓝鲸样本，开展了微卫星（microsatellite）与线粒体DNA（mtDNA）序列分析。分析结果显示，ETP海域的使用模式存在南北东太平洋蓝鲸群体的分化：前者更倾向于中美洲外海被称为哥斯达黎加海隆（Costa Rican Dome）的海域，后者则偏好秘鲁与厄瓜多尔周边水域。尽管南半球整体的遗传变异模式与近期提出的智利蓝鲸亚种分类地位相符，但现有已发表的形态学数据仍存在部分不一致之处，且不能假定智利海域内的所有蓝鲸均属于该亚种。此外，提议中的智利蓝鲸亚种的分布范围至少应在季节尺度上扩展至ETP海域，或许还应纳入东北太平洋区域。