The Sea Otter Population as of now is currently decreasing, and there's an estimated 106,000 worldwide as of today, and although the conservation efforts have helped, recently there has been a small decrease every year since its peak in 2016.

The Reason

Their population has decreased due to shark attacks disease, and parasites, but many of them are due to man, such as fishing nets, oil spills, fisherman caging or killing them for competition, the destruction of their habitat and a history of fur trade due to their fur being some of the thickest within the animal kingdom, hence how they float.