Steller's Sea Cow - Sighted?

Steller's Sea Cow - Sighted?

A scattered handful of reports claim to have spotted Steller's sea cows, a species long thought to have been extinct.  But are they really?  Could there be a relict population left, or are the reports just mistaken?

The Steller's sea cow was the largest of the sirenians, a group of aquatic mammals which also includes the dugong and manatees.  Most manatees and dugongs are around 10 feet long, but the Steller's sea cow was about 30 feet long.

Although manatees and dugongs are both tropical species, the Steller's sea cow was native to the cold waters of the North Pacific.  In the fossil record, the Steller's sea cow was common along the shores of the entire North Pacific, from northern California up and around all the way to Japan. 

Unfortunately for the Steller's sea cow, it was a large, edible, useful, and extraordinarily tame animal.  These peaceful giants basically lay bobbing in the surf, grazing slowly on kelp, until some hunter came up and killed them.  Their meat was highly prized, their skins useful to the fur trade, their fat an excellent fuel for lamps.

Aboriginal hunters had persecuted the Steller's sea cow long before the white explorers ventured into Alaska.  By the time that Georg Steller discovered it, the gigantic sirenian was confined to an extremely small relict population off the Commander Islands off the shores of the Kamchatka peninsula. 

A mere 27 years after its discovery by Western explorers, the Steller's sea cow was gone.  By 1768, it was officially declared extinct.

Nevertheless, there have been occasional sightings of a sea cow-like animal in the 242 years since.  One factor working against acceptance of these sightings is the simple physical fact of the Steller's sea cow.  This was not a creature of the briny deep, but a shoreline-hugging animal, 30 feet long, and extremely tame.  Granted, the coastline of Canada and Alaska is fairly remote.  And yet the entire length is subject to ferries, cruise ships, kayakers, professional and sport fishing crews.

Cryptomundo carries an account
of the most recent sighting, along with a drawing made by the fisherman in question.  His description of the animal as calmly bobbing in the waves certainly seems sea cow-like.  Obviously the distance of the sighting, and the fog in the area, can make identification difficult to say the least.

But one major problem remains with this sighting: it happened some 40 miles off the coastline.  It's tempting to think "maybe they all swam out to sea to escape hunters, and that's why we haven't seen them."  Except for the problem that the Steller's sea cow was entirely herbivorous, and there is no kelp to eat on the open ocean.  Kelp only grows in the shallow coastal waters, where it can receive sunlight.  It simply wouldn't be possible for a Steller's sea cow to survive out in the deep ocean.

However, there is a large blubbery gray mammal which is often found out in the open ocean of the north Pacific.  The elephant seal not only fits the bill perfectly, its profile also bears a remarkable similarity to the one sketched after the most recent sighting.

Sadly, it seems that the Steller's sea cow is, and continues to be, long extinct.


Photo credit: Flickr/yathin