ESR 18:163-167 (2012)  -  DOI: https://doi.org/10.3354/esr00440

ABSTRACT: Genetic analysis of 49 biopsy samples from North Pacific right whales Eubalaena japonica in the eastern (48) and western (1) North Pacific revealed 24 individual whales with 7 mitochondrial haplotypes. Three pairs of large and small individuals were identified in the field; genotype analysis indicated that 2 of these could represent mother−offspring pairs; for the third small individual, no sampled female genetically qualified as a potential mother. In aggregate, the population appears to have lost some genetic diversity, though not to the degree of North Atlantic right whales E. glacialis, and males outnumber females 2:1. A comparison of the eastern Pacific samples to a single Russian sample suggested that the 2 populations are isolated to some degree. The effective population size for the eastern North Pacific was calculated to be 11.6 (95% CI: 2.9−75.0), based on the estimated linkage disequilibrium. These results further indicate that this population is at immediate risk of extirpation.

KEY WORDS: Critically Endangered species · Mammal · IUCN Red List category · Eubalaena japonica · Genetics · Right whales