They were never part of the endangered species list. Actually Their Endagered in About 12 Areas.
Orcas (killer whales) eat the sea otter which is partly why they are an endangered species.
Extinct Steller's Sea Cow Bhaji River Dolphin Endangered Sea Otter Manatee
becausepeople use them for fur hats and used to trade there skin
The Otter is threatened and not yet endangered.
I wonder who told you that, in natural habitats, predators (killer whales) prevent overpopulation of their prey (sea otters). If you want to point fingers at the cause of the sea otter decline, point at hunters and poachers, because of them, many species have become endangered or extinct.
In the United States, the sea otter can be found along the Pacific Coast. The largest sea-otter populations are located off the coasts of Alaska and central California, but some sea otters have been seen near Oregon and Washington.
In the US, there are both federal laws and state laws that protect the otter. These laws make it illegal to hunt, harrass, or capture sea otters.
I think mammals... but I am not 100% sure...
The sea otter is a mammal and is a vertebrate.
It has resulted in rapid decline in otter population and the species has become endangered.
when you died