The dynamic daily life of blue whales

When Virginia Andrews-Goff managed to place satellite tracking beacons on two blue whales, she became the first person, and so far the only person, to do so. The feat took place in the Antarctic Ocean.

In recent times it is very difficult to see Antarctic blue whales. Commercial whaling in the 1960s and 1970s killed some 290,000 Antarctic blue whales, representing 90% of the population. In the late 1990s, the global population of Antarctic blue whales was estimated at 2,280 individuals. The blue whale is in danger of extinction. Knowing where the specimens to protect move is of great help to establish protection measures.

Analysis of the data from tracking the activity of both whales, made thanks to satellite tracking beacons, has provided new and revealing information about the daily lives of these animals, consummate nomads.

Satellite beacons showed the whales covered 1,390 kilometers in 13 days and 5,550 kilometers in 74 days, with an average distance of more than 100 kilometers per day.

The two whales did completely different things, but what became clear is that these animals can travel really fast, Andrews-Goff emphasizes.

Given how far and how fast these animals traveled, protecting the general population of Antarctic blue whales from potential threats will be difficult, as they could circumnavigate Antarctica in a single feeding season.

An Antarctic blue whale. (Photo: Australian Antarctic Division)

Two displacement rhythms were observed: a faster one, apparently used to travel from one place to another, with an average speed of 4.2 km/h, and a slower one, of 2.5 km/h, which apparently corresponds to the action of inspecting the environment in search of food.

It seems that the whales stay in one area to feed and then quickly travel to another area and stay there for a while to feed again.

Even with a sample size as small as 2, findings from satellite beacon tracking will help the International Whaling Commission better manage the protection of Antarctic blue whales, providing groundbreaking insights into the foraging ecology of blue whales. , habitat preferences, feeding, distribution and movement rates. These data will serve as the basis for an in-depth assessment of Antarctic blue whales beginning in 2024.

The study is titled “Satellite tag derived data from two Antarctic blue whales (Balaenoptera musculus intermedia) tagged in the east Antarctic sector of the Southern Ocean”. And it has been published in the academic journal Biodiversity Data Journal. (Fountain: NCYT by Amazings)