Scientists at the University of New South Wales (Australia) have discovered a previously unknown population of pygmy blue whales, the smallest subspecies of blue whales, in the Indian Ocean, due to the Organization of the Comprehensive Nuclear Test Ban Treaty (CTBTO), said in a statement from the university.
The whales gave out their singing, which was recorded by the hydrophones of an organization designed to monitor, among other things, possible underwater nuclear weapons tests.
“We have discovered a whole new group of pygmy blue whales right in the middle of the Indian Ocean. We do not know how many whales there are in this group, but we suspect there are many from the sheer number of sounds we hear,” said Tracy Rogers, senior study author and professor at New University. South Wales.
Studying the CTBTO data, scientists discovered an unusually strong signal – a whale song that had previously been identified in the recordings. After examining the song’s structure, frequency, and tempo, the researchers realized that it belongs to a group of pygmy blue whales, but does not belong to any of the groups previously recorded in the area. If visual observations confirm the presence of a new population, it will become the fifth population of pygmy blue whales found in the Indian Ocean.
The dwarf blue whales are the smallest members of the blue whale family, they can reach 24 meters in length. Whale songs can be heard at a distance of up to 500 km.
“Blue whales in the Southern Hemisphere are difficult to study because they live offshore and don’t jump around – they’re not show-ponies like the humpback whales,” says Prof. Rogers.