Genetic analysis of right whales in the eastern North Pacific confirms severe extirpation risk

摘要

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.