The fauna of cetaceans of the Commander Islands now includes 22 species.

In September, at the mouth of the Sarannaya River on Bering Island, a fallen dolphin was discovered.  When the CINP scientific department learned about the find, they examined the remains and studied the photographs. Immediately a version appeared - the animal was a striped dolphin (Stenella coeruleoalba). The remains were not very well preserved and there was a need to clarify the correctness of the definition of the species.

Therefore, we decided to send samples for genetic research. The result confirmed that the animal was a striped dolphin Stenella coeruleoalba.

Striped dolphins reach 2-2.5 meters in length. Their distinctive feature are dark oblique stripes on the sides of the animal. They feed on fish and cephalopods. They prefer to stay in groups ranging from several individuals to a hundred.

For the Commander Islands water area, the find of a striped dolphin is the first reliable registration of the species, previously there was no documentary evidence of animals coming to the islands.  One can only guess what caused the animals to expand or shift their range, however, this is not the first time a species has been recorded at higher latitudes. For example, in August 2017, a dead dolphin was found on the Khalaktyrsky beach in Petropavlovsk-Kamchatsky city, and on October 2022 near Oktyabrskoye Village, locals rescued a live striped dolphin.

"For several years now, we have seen significant changes in the ice cover of the North Pacific Ocean and, in particular, the Bering Sea. The Bering Sea is the largest of the Far Eastern seas of Russia. It is located between two continents - Asia and North America. Usually in March, the ice covers considerable distances from the Bering Strait to the south, almost to the Aleutian Islands. However, as the research of our colleagues shows, in the winter of 2019, the ice coverage in the Bering Sea was minimal within the past 5.5 thousand years. Probably, climate change lead to changes in marine ecosystems, which is connected to the expansion of the ranges of species, such as striped dolphins", said Evgeny Mamaev, Deputy Director for Science.

Source of the title image:

 https://ru.wikipedia.org/wiki/%D0%9F%D0%BE%D0%BB%D0%BE%D1%81%D0%B0%D1%82%D1%8B%D0%B9_%D0%B4%D0%B5%D0%BB%D1%8C%D1%84%D0%B8%D0%BD