On Sunset Island, near the southern end of the reach, Steller sea lions have set up house. One of the largest sea mammals, an adult male can reach more than 900 kilograms (2,000 pounds), heaving their weight around and hauling up on the rocks to protect their harems. To the east of Sunset Island, harbor seals have grabbed the territory. Beyond the question of size (seals might weigh some 130 kilograms, around 300 pounds), the quick and easy way to tell seals and sea lions apart is by their ears—sea lions have an external flap to their ears, but seals don’t.