Steller’s sea cow – candidate for de-extinction?

Today in Evolunch, we discussed de-extinction.  One species we evaluated for post-extinction-reintroduction via the magic of genetics is the Steller’s sea cow, extinct in the wild since 1768 (less than 30 years after it was “discovered”) .

Below is an excerpt from The Unnatural History of the Sea by Callum Roberts that describes the discovery and subsequent loss of Steller’s Sea Cow on Bering island in the mid-18th century. Roberts begins with the trials of an expedition led by Captain Vitus Bering and his men, stranded on Bering Island in the frigid north Pacific in 1741/1742. The descriptions of the now extinct Steller’s Sea Cow by German naturalist Georg Steller is particularly poignant.

The except starts here:

By the dawn of the eighteenth century, two hundred years of European exploration had sketched out much of the world’s coastline. But the north pacific, stretching from eastern Russia and Japan to North America, and the Southern Ocean, the name given to the waters  around  Antarctica, remained unknown and thereby enticing to adventures of the day…

As the winter set in, the land disappeared under deep snow. But food remained plentiful in the form of  sea mammals. The naive sea otters could still be approached and clubbed with ease. The otters, wrote Steller,

at all seasons of the year, more, however, during the winter than in the summer, leave the sea in order to sleep, rest, and play all sorts of games with each other…it is a beautiful and pleasing animal, cunning and amusing in its habits, and at the same time ingratiating and amorous. Seen when they are running, the gloss of their hair surpasses the blackest velvet.

When the expedition first reached Bering Island, otters were abundant and encountered in groups of ten, sometimes up to a hundred. But with hunting numbers soon thinned, and the remaining animals eventually became wary, forcing men to seek quarry farther afield, then to drag the carcasses home over difficult terrain. In November and December, they could catch otters 3 to 4 kilometers from the camp [2 miles], in January 6 to 8 kilometers [4 to 5 miles], in February 20 kilometers [12 miles], and in March and April they had to travel up to 40 kilometers away [25 miles]…

It was at this time that the men turned their attention to an animal that had actually been nearby all winter-the sea cow. Steller’s description of the sea cow remains one of the only eyewitness accounts, for the beast survived but a brief moment in time following its discovery.

Along the whole shore of the island, especially where steams flow into the sea and all kinds of seaweed are most abundant, the sea cow … occurs at all seasons of the year in great numbers and in herds… The largest  are four to five fathoms long [~ 7 to 9 meters or 24 to 30 feet] and three and a half fathoms thick about the region of the navel where they are the thickest [~ 2.25 meters or 8 feet diameter ]. Down to the navel it is comparable to the land animal; from there to the tail, a fish.The head of the skeleton is not  the least distinguishable from the head of a horse, but when it is still covered with skin and flesh, it somewhat resembles the buffalo’s head, especially as concerns the lips. The eyes of this animal, without eyelids, are no larger than a sheep’s eyes . . .The belly is plump and very expanded, and at all times so completely stuffed that at the slightest wound the entrails at once protrude with much hissing. Proportionately, it is like the belly of a frog . . . .

Like cattle on land, these animals live herds in together in the sea, males and females usually going with one another, pushing the offspring before them all around the shore. These animals are busy with nothing but their food. The back and half of the belly are constantly seen outside the water, and they munch along just like land animals with a slow, steady movement forward. With their feet they scrape seaweed from the rocks, and they masticate incessantly . . . When the tide recedes, they go from the shore into the sea, but with the rising tide they go back again to the beach, often so close we could reach and hit them with poles. . . . They are not the least bit afraid of human beings. When they want to rest on the water, they lie on their back in a quiet spot near a cove and let themselves float slowly hear and there.

The sea cows, although docile, did not give up without a fight. Steller recounted,

I could not observe indications of an admirable intellect . . . . but they have indeed an extraordinary love for one another, which extends so far that when one of them was cut into, all the others were intent on rescuing it and keeping it from being pulled ashore by closing a circle around it. Others tried to overturn the yawl. Some placed themselves on the rope or tried to draw the harpoon out of it’s body, which indeed they were successful several times. We also observed that a male two days in a row came to its dead female on the shore and enquired about it’s condition. Nevertheless, they remained constantly in one spot, no matter how many of them were wounded or killed.

The fat of this animal is not oily or flabby but rather hard and glandular, snow-white, and, when its been lying in the several days in the sun, as pleasantly yellow as the best Dutch butter. The boiled fat itself excels in sweetness and taste the best beef fat, is in colour and fluidity like fresh olive oil, in taste like sweet almond oil, and of exceptionally good smell and nourishment. We drank it by the cupful without feeling the slightest nausea. . . . The meat of the old animals is indistinguishable from beef and differs from the meat of all land and sea animals in the remarkable characteristic that even in the hottest summer months it keeps in the open air without becoming rancid for two whole weeks and even longer, despite its being defiled by blowflies that it is coved with worms everywhere.

The rest,as they say, is history. Steller and his companions completed the ship and escaped Bering Island on August 14, 1742, sighting Kamchatka just three days later. They carried with them seven hundred sea otter pelts but left behind much of Steller’s painstakingly gathered scientific specimens for lack of space.

Word of newly discovered lands and their rich stocks of sea otters and seals proved irresistible, and hunting expeditions were quickly mounted.

In 1755, an engineer called Jakovlev visited Bering Island and the nearby Copper Island to prospect for ore. He was so struck by the speed of decline of sea cows that he petitioned, unsuccessfully, the Kamchatkan authorities to restrict their capture. Martin Sauer, writing in 1802 on Bering’s expedition, said “the last sea cow was killed on Bering Island in 1768 and none has been seen since.”






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