This video says about itself:
7 April 2015
“When you see a sea otter, they’re usually either eating or digesting,” often munching on urchins, says ecologist Anne Salomon, a Pew marine fellow. That’s a good thing for some kelp beds. Without otters to control urchin numbers, the spiky shellfish can devour the beds, leaving barren seascapes behind.
Fifty years ago, sea otters were so sought after for their fur that they disappeared from the Canadian coast. But now they’re bouncing back and—as seen in this video—competing with humans for the region’s shellfish.