An ‘aggressive’ sea otter is snatching surfers’ boards. Experts are puzzled

There is no clear explanation for the sea mammal's behavior, say authorities, who has been seen riding and gnawing surfboards

A California otter is making headlines for her unique, and worrying, interactions with surfers.

In recent weeks, Mark Woodward, a photographer who goes by Native Santa Cruz on Twitter and Instagram has been sharing photos and videos of southern sea otters riding on surfboards they've commandeered. Authorities are particularly concerned about one sea otter, known as 841, who was involved in multiple incidents and can be seen in a video relentlessly gnawing on a board that the aquatic mammal scared a rider off of.