The presence of Steller's sea cows in the Aleutian Islands may have caused the Aleut people to migrate westward to hunt them.
This possibly led to the sea cow's extinction in that area, assuming the animals survived in that region into the Holocene epoch, but there is no archaeological evidence.

It has also been argued that the decline of Steller's sea cow may have been an indirect effect of the harvesting of sea otters by the area's aboriginal people.
With the otter population reduced, sea urchin population would have increased, in turn reducing the stock of kelp, its principal food.
In historic times, though, aboriginal hunting had depleted sea otter populations only in localized areas, and as the sea cow would have been easy prey for aboriginal hunters, accessible populations may have been exterminated with or without simultaneous otter hunting.
In any event, the range of the sea cow was limited to coastal areas off uninhabited islands by the time Bering arrived, and the animal was already endangered.

One factor potentially leading to extinction of Steller's sea cow, specifically off the coast of St. Lawrence Island, was the Siberian Yupik people who have inhabited St. Lawrence island for 2,000 years.
They may have hunted the sea cows into extinction, as the natives have a dietary culture heavily dependent upon marine mammals.
The onset of the Medieval Warm Period which reduced the availability of kelp may have also been the cause for their local extinction in that area.
The presence of Steller's sea cows in the Aleutian Islands may have caused the Aleut people to migrate westward to hunt them. This possibly led to the sea cow's extinction in that area, assuming the animals survived in that region into the Holocene epoch, but there is no archaeological evidence.
It has also been argued that the decline of Steller's sea cow may have been an indirect effect of the harvesting of sea otters by the area's aboriginal people. With the otter population reduced, sea urchin population would have increased, in turn reducing the stock of kelp, its principal food. In historic times, though, aboriginal hunting had depleted sea otter populations only in localized areas, and as the sea cow would have been easy prey for aboriginal hunters, accessible populations may have been exterminated with or without simultaneous otter hunting. In any event, the range of the sea cow was limited to coastal areas off uninhabited islands by the time Bering arrived, and the animal was already endangered.
One factor potentially leading to extinction of Steller's sea cow, specifically off the coast of St. Lawrence Island, was the Siberian Yupik people who have inhabited St. Lawrence island for 2,000 years. They may have hunted the sea cows into extinction, as the natives have a dietary culture heavily dependent upon marine mammals. The onset of the Medieval Warm Period which reduced the availability of kelp may have also been the cause for their local extinction in that area.
Steller's sea cow