Genetic Study Suggests Arabian Sea Humpback Whales Are an Entirely New Subspecies

A genetic analysis of 25 years of whale data suggests that Oman's resident Arabian Sea humpback whales are a distinct fourth subspecies, isolated from every other humpback population on Earth, according to Good News Network.

The only humpbacks that never migrate

Unlike every other humpback population, Arabian Sea whales stay in Omani waters year-round instead of migrating between feeding and breeding grounds. They're able to do this because the southwest monsoon drives seasonal deep-ocean nutrient upwelling, creating feeding conditions in tropical waters that are normally only found at higher latitudes.

Tens of thousands of years of separate evolution

Researchers from the Wildlife Conservation Society, working with Omani environmental authorities, compared mitochondrial DNA from 2,285 whales worldwide. The Arabian Sea population showed significant genetic differentiation from the three recognized humpback subspecies, with genetic lineages diverging an estimated 43,000 to 113,000 years ago. A separate 2018 study also found these whales sing songs with zero overlap to populations elsewhere in the Indian Ocean.

"Their own evolutionary trajectory"

"The results clearly indicate the Arabian humpback whales have followed their own evolutionary trajectory for tens of thousands of years," said lead researcher Dr. Rita Amaral. The population remains small and hasn't grown in two decades, facing threats from fishing gear, vessel strikes, noise, and climate-driven shifts in the monsoon patterns it depends on.