According to US media reports, the Russian Navy also uses military-trained dolphins to protect its fleet in the Black Sea.

Two underwater enclosures were placed at the entrance to the port of Sevastopol, the independent US Naval Institute (USNI) wrote on its news portal on Wednesday (local time).

Satellite images suggested the pens were moved there in February, around the time Russia's attack on Ukraine began.

It is conceivable that the dolphins will be used to repel enemy divers who might try to enter the harbor and sabotage warships.

Many of them are currently out of range of Ukrainian missiles.

The Washington Post wrote that the US satellite photo service Maxar shares the assessment of the USNI experts.

The provider had made the relevant recordings available to the newspaper.

Given their excellent sense of hearing, the marine mammals are able to detect mines and other potentially dangerous objects, it said.

The US military has also been training dolphins and sea lions to use against underwater threats since the 1960s.

Using animals to detect mines

According to the US Naval Institute, based in Annapolis, Maryland, the Soviet Navy developed several marine mammal programs during the Cold War, including one using so-called combat dolphins near Sevastopol.

After the collapse of the Soviet Union, it went to the Ukrainian military, but then came under the control of the Russian Navy as a result of the Russian annexation of the Crimean peninsula in 2014.

Since then, these programs have been expanded.

In addition to dolphins and sea lions, other animals are also used for military purposes - often also to track down mines.

In addition to tracking dogs, this task can also be performed by rats or bees, for example.

The latter are said to be even more effective when searching for mines than expensive search devices or sniffer dogs.

Tens of thousands of bees can search a large area in a relatively short time without accidentally setting off mines.

For example, the trained animals are trained to associate the smell of the explosive material with food.

They then swarm near buried mines hoping to find food there.

Horses and mules are also used to transport military equipment.

The mountain troops of the Bundeswehr, for example, use them to maneuver through the most remote passages.