The Missing Mammal That May Have Shaped California’s Kelp Forests

The Steller’s sea cow, an extinct relative of the manatee, could grow to five tons and 25 feet long and roamed the coastal waters of the northern Pacific Ocean. Although they were named for him, Georg Wilhelm Steller, a German zoologist who observed the animals between Asia and North America in 1741, described them as something like seaweed-and-kelp gluttons.

“These animals are very voracious and eat incessantly, and because they are so greedy they keep their heads always under water, without regard to life and safety,” Steller wrote in his book “On the Beasts of the Sea.”

Only a couple of decades after Steller’s initial encounter, his namesake sea cow went extinct. The role of humans in this extinction is debated. The mainstream view is that hunting decimated the population, but