2018: STELLER’S SEA COW

For 2018, RDLS invites events on or around November 30th to mark the extinction and endangerment of marine mammals and/or the ongoing threats to seas. The focal lost species for 2018 is Steller’s sea cow. Alternatively, RDLS participants are welcome to focus on any lost or disappearing species or ecological community – please see our list of suggested activities.
Steller’s sea cow: Steller’s sea cow (Hydrodamalis gigas) was a large marine mammal whose living relatives are the dugong and the manatee. Steller’s sea cow was last seen in 1768 in the Bering Sea between Alaska and Russia, just a few years after it was first observed and named by Europeans. 2018 marks the 250th anniversary of its extinction. The story of Steller’s sea cow story has much to teach about how species can be extinguished with shocking speed.Steller’s sea cow was named by Georg Wilhelm Steller, a German naturalist who noticed the creatures whilst shipwrecked on Bering Island during a scientific mapping expedition of the Arctic. Much of what is known about the sea cow comes from Steller’s 1741 observations. Fur hunters, who then set up a trading post on the island, subsisted on sea cows, which were easy to hunt as they were slow moving and rarely submerged. All the sea cows were gone by 1768.

Growing up to nine metres in length and weighing up to ten tonnes, Steller’s sea cows provided refuge for many species, including fish, several species of crustaceans now extinct, and resting birds. They communicated with sighs and snorts, fed mainly on kelp, and were monogamous and sociable. Mothers nursed and raised one baby at a time.

Illustration by by F. John