Arabian Sea Humpback Whale Isolated for 70,000 Years

The Arabian Sea humpback whale may be the most isolated humpback population on the planet, keeping its home in the same place for tens of thousands of years. That's the conclusion reached in a new study of the marine mammal conducted by a research team from the Wildlife Conservation Society and the American Museum of Natural History.

The whale, currently classified as "Endangered" on the International Union for Conservation of Nature's (IUCN) Red List of threatened species, has proved difficult to study due to a limited amount of data from which to work. But the authors of a study just published in the journal PLOS ONE were able to analyze tissue samples from 67 Arabian Sea humpback whales, focusing on both mitochondrial and nuclear DNA.

The team then compared its genetic analyses with existing data from humpback whale populations in both the Southern Hemisphere and the North Pacific. They found that the Arabian Sea humpback is highly distinct from the Southern Hemisphere and North Pacific populations.

Meanwhile, the team's analysis of the gene flow of the creature suggested the Arabian Sea humpback originated in the Southern Indian Ocean. But it came to be isolated in the Arabian Sea, and has been there for 70,000 years. A fact that's "remarkable for a species that is typically highly migratory," the researchers wrote.

As a key follow-on to their findings, the researchers consider the Arabian Sea humpback's low prospects for abundant reproduction, as well as threats posed to it by mankind, and recommend that the whale be designated "Critically Endangered" on the IUCN's Red List.

From Discovery News