Details of the study

The blue whale is the largest animal on the planet; It grows up to 30 meters tall. It is also an endangered species that lives in a remote habitat, so tracking it across the vast expanses of the ocean is not easy.

Passive acoustic devices called Sonobuoys came to the aid of scientists. These are special buoys that can detect sonar; They can pick up the calls of Antarctic blue whales (Balaenoptera musculus intermedia) when diving into the ocean, locate them, and locate them for further study.

Analysis provides the most up-to-date polar information on the distribution of these rare and elusive game animals [й довели до] Extinction limits during commercial whaling,
– says Brian Miller of the Australian Antarctic Programme, which studies marine mammals.

Scientists say we can reliably listen to whales, swim up to them and visually see them, then photograph and track them, and even take small biopsies of their skin and subcutaneous fat for further study.

The team noted three distinct high and low vocal calls, two of which are produced only by blue whales In this part of the ocean:

• Z call (Z call) made only by males.
• Unit A-shout (Unit-A), which is a specific part of the Z-shout.
• The third signal is a “social” signal known as the D-call, produced by all populations of blue whales with both male and female feeding grounds.

Three types of blue whale calls / Photo: Brian Miller

Studying the nature of these calls helps track whale populations over time.

The most prevalent signal overall was the Unit-A signal, which was detected in the largest number of sonobuoys across Antarctica and sub-Antarctica. While scientists noted more non-song D calls early in the summer feeding season, Unit-A and Z calls were more common in late summer and early fall.

Despite It is unclear what exactly these signals meanThey can be combined with other data recorded by drones and artificial intelligence algorithms to assess blue whales’ movements and various aspects of their behavior.

As the planet adapts to climate change, the researchers hope that the techniques they developed in this new study can be used to monitor possible impacts on blue whale populations and their food. Further studies could use unmanned vessels equipped with hydrophones (underwater microphones) and other instruments to record calls and swimming speeds, potentially linking different call types to different feeding patterns.

The scientists are confident that “the collected data sets will serve as a basis and springboard for further studies” and that passive acoustic monitoring will play a critical role in future research aimed at filling knowledge gaps about Antarctic blue whales.