A population survey has been conducted by US Geological Survey researchers and it’s found that numbers are down again. It is believed that human and natural factors are affecting the decline, and new research is under way to try and work out what exactly is causing numbers to fall.

Southern sea otters are listed as an endangered species and can be found around the northern and eastern North Pacific Ocean. They are among the smallest of marine mammals.

Check out the video of some sea otters below: