Sea otters, Prince William Sound, Alaska, United States

Otterly cool

Think sea otters are just about whiskers and floating naps? There's much more behind those button eyes. In Prince William Sound, in Alaska, United States, they drift on ice or crack shellfish on their bellies with a favourite rock, as seen in today's image. Less obvious is how their taste for sea urchins helps protect kelp forests. Otters also depend on clean, cold water—their fur traps air for warmth rather than repelling water, making them highly vulnerable to oil spills.