Humpback Whales in the Arabian Sea Have Been Isolated for 70,000 Years

Powerful genetic tools have given scientists a new means for sniffing out the existence of previously concealed species—that two species of dolphin are actually four, that Brazil has an extra species of adorable wildcat, and that the Caribbean has 24 new, imperiled species of lizards. Now, a similar discovery has emerged for humpback whales. Researchers found that one population of those gentle giants, while not a distinct species, has remained isolated in the Arabian Sea for upwards of 70,000 years. 

Humpback whales are normally migratory, continuously journeying around the Southern or Northern hemispheres throughout their lifetime. In the Arabian Sea, however, the whales stay in place. But despite their homebody tendencies, that population has proven difficult to study in the past, Discovery News writes. 

Now, researchers have finally managed to get their hands on samples from 67 of the Arabian whales. When the researchers compared these with genetic samples from the global population, they found that the Arabian whales likely made their way to their present locations from the Southern Indian Ocean and that their journey took place around 70,000 years ago.

While their degree of genetic divergence doesn't warrant classification as a new species, it does mean the whales are highly distinct and probably rank as "the world's most isolated humpback whale population," the authors write. 

Humpback whales as a species are listed as "least concern" by the International Union for Conservation of Nature—they're in no danger of going extinct any time soon. The population living in the Arabian Sea, however, is currently listed as endangered. But the researchers think this group of whales is so unique and faces such serious threats that it should get a new designation: critically endangered. 

Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.