Sea otters are thriving and their population is growing at a rate faster than any other marine mammal in the park. This species was nearly extirpated from Southeast Alaska by the Russian fur trade but is now on the rebound. Sea otter sightings in Glacier Bay were rare before 2000; now they number in the thousands! Biologists acknowledge that the population explosion we are witnessing is not sustainable. It is unknown whether the population will continue to grow, level off, or crash. Photographer: Sean Neilson