Georg Wilhelm Steller described the extinct sirenian Steller’s sea cow in 1741. It was only found near the Commander Islands in the Bering Sea between Alaska and Russia at the time; during the Pleistocene period, its range expanded over the North Pacific, but it likely reduced to such an extreme degree owing to the glacial cycle. It’s conceivable that native peoples had contact with the animal before Europeans arrived. When the crew of Vitus Bering’s Great Northern Expedition felt stranded on Bering Island, Steller first encountered it. Much of what we know about it comes from Steller’s observations on the island, which were reported in his posthumous book On the Beasts of the Sea. The slow-moving and easily caught creature was killed to extinction for its meat, fat, and hide within 27 years of its discovery by Europeans.
The last Steller’s sea cows around the Commander Islands, according to genetic data, were the last of a much larger population spread over the North Pacific coastal zones. They have the same genetic variety as Wrangel Island’s last and most inbred group of woolly mammoths. Suitable habitats significantly declined during glacial eras and reductions in sea levels and temperatures, fragmenting the population. The population had already collapsed by the time sea levels stabilized some 5,000 years ago.
The Aleut people may have migrated westward to hunt Steller’s sea cows since they were present in the Aleutian Islands. This may have resulted in the extinction of the sea cow in that area, if it had not previously occurred, although archaeological evidence is ambiguous. The Siberian Yupik people, who have lived on St. Lawrence Island for 2,000 years, were one cause that may have contributed to the extinction of Steller’s sea cow, notably off the coast of St. Lawrence Island. Because the locals’ food is primarily reliant on marine animals, they may have hunted the sea cows to extinction. The advent of the Medieval Warm Period, which diminished kelp availability, may have also contributed to their demise in that region. It’s also been suggested that the fall of Steller’s sea cow was caused in part by aboriginal people hunting sea otters in the region. Because the otter population was reduced, the number of sea urchins rose, lowering the stock of kelp, which is their primary meal. Aboriginal hunting diminished sea otter numbers only in limited locations in the past, and because the sea cow would have been easy prey for aboriginal hunters, accessible populations may have been eradicated with or without otter hunting. By the time Bering arrived, the sea cow’s range had been reduced to coastal areas near deserted islands, and the animal was already endangered.
After Brandt’s stated extinction date of 1768, sightings of sea cows have been observed. According to Lucien Turner, an American ethnologist and naturalist, the sea cows lived until the 1800s on Attu Island and were occasionally killed. A report in the official magazine of the USSR Academy of Sciences announced a potential encounter in 1963. A group of big marine animals feeding on seaweed in shallow water near Kamchatka, in the Gulf of Anadyr, was observed by the whaling ship Buran the previous year. Six of these creatures, with trunks and split lips, were seen by the crew, ranging in length from 6 to 8 meters (20 to 26 feet). Local fisherman have also reported sightings in the northern Kuril Islands, as well as the Kamchatka and Chukchi peninsulas.