Most humpback whales travel thousands of kilometers every year. They eat in cold seas and have babies in warm seas. But one group in the Arabian Sea stays in the same place all year.

Scientists studied the genes of these whales. They found that this group is clearly different from other humpback whales. The scientists want to call it a new subspecies. But there are only a few whales, so they need protection.

Most humpback whales are long-distance travelers. Every year they swim between cold feeding areas and warm breeding areas. The humpbacks of the Arabian Sea are different. They stay in the same region all year round.

An international team, including the Wildlife Conservation Society in the US, compared genetic samples collected in Oman with data from the three recognized subspecies. The Arabian Sea whales were clearly different from all three.

The team also examined an old specimen found in Iraq and confirmed that it was a humpback closely related to this population. Based on these results, they proposed recognizing the group as a fourth subspecies. The researchers also warned that there are not many of these whales and that human activities put them in serious danger.

Humpback whales typically migrate thousands of kilometers between high-latitude feeding grounds and tropical breeding grounds, but one population breaks this pattern. Whales in the Arabian Sea remain in the region year-round, and earlier research had already described them as possibly the most isolated humpbacks on Earth. In a study published in Frontiers in Marine Science, an international team including the Wildlife Conservation Society compared samples from Oman with genetic data from the three currently recognized subspecies in the North Atlantic, the Southern Hemisphere and the North Pacific, none of which had included Arabian Sea whales.

Genetic differentiation values of roughly 0.12 to 0.24 indicated clear separation. The researchers also identified a historical type specimen from Iraq as a humpback closely related to the current population. Combining this evidence with the whales' non-migratory behavior and reproductive isolation, they proposed a fourth subspecies, whose genetic differentiation may have developed over a period of about 43,000 to 113,000 years. It should be stressed, however, that this is a proposal; classification is settled through further expert debate. Meanwhile, this population has few animals, shows no evidence of growth over two decades, and faces intensifying human threats.