About the Cover

This sea otter in the Prince William Sound of Alaska may be identified and studied from a distance, avoiding stress and injury to the animal thanks to a photographic computer system called the Sea Otter Nose Matching Program, or SONMaP. (See page 19 for study findings.) The pristine-looking waters of the Prince William Sound belie the pollution that remains from the Exxon Valdez oil spill two decades ago. On the shore, just below the surface, the oil is readily apparent. (See the back cover for the full story.)