It has become known why grey whales release giant bubbles

It turned out that whales release bubbles to make diving easier. Most often this is done by large whales. This is stated in a scientific article on the website of Wiley Online Library.

Bubbles for grey whales have become a multifunctional tool. They help whales dive into the water and corner prey. There is speculation that bubbles may also be used for communication.

Animals are always looking to conserve energy. For example, the body of fish is streamlined to minimise water resistance. The process of feeding requires high energy expenditure because the animal is both receiving and expending resources at the same time.

Marine mammals, such as northern sea elephants, have to spend a lot of energy and time hunting. They adapt to different pressures and hold their breath. Some animals, for example, exhale to make it easier to dive if prey is at depth. But what do those that feed in shallow water, like whales, do?

Biologists from Europe and the US have studied grey whales feeding in shallow water. In a new study published in the journal Ecology and Evolution, scientists confirmed that bubbles help whales save energy and dive more easily. To do this, they analysed drone footage taken over seven years.

The study group consisted of 75 grey whales that feed off the coasts of Northern California and British Columbia at depths of less than 20 metres from June to November. The whales eat zooplankton and other invertebrates. They use a variety of hunting tactics: vertical head-down stance, sideways or forwards near the bottom. The vertical "headstand" has proven to be the most popular, although it is energy intensive.

Whales released bubbles an average of 27 seconds after the start of the dive, most often in an upright position. Longer whales, which are more difficult to dive, released bubbles more frequently. This increased their time underwater and probably helped conserve oxygen.

Other whale species, such as sperm whales and bowhead whales, also use bubbles to dive. Humpback whales corral prey using bubbles. There is speculation that grey whales may communicate through bubbles, but there is not enough data yet. Perhaps blowing bubbles is a behavioural adaptation transmitted through group learning.