In Alaska, Harbor seals breed in July through August and females give birth to a single pup the following May or June after a 10 month gestation. Harbor seal milk has 10 times the fat content of cows milk; so seal pups grow rapidly. Pups are 3 feet long and weigh 25 pounds at birth, and within a month, they will have doubled in size. Harbor seal pups will become breeding adults in 3-5 years, and can live for 30 years in their coastal waters or estuarine habitats.
During the summer months, harbor seals are commonly found in fjords, such as ones found in Glacier Bay, Prince William Sound, Kenai Fjords National Park, and Tracy Arm Fjords. Hundreds of harbor seals haul out to have their pups on top of drifting ice floes in glacier-fed waters, which offer refuge from terrestrial predators, such as bears. In addition, orcas dont usually hunt in these silty, ice-choked fjords. For example, deep within the West Arm of Glacier Bay lies Johns Hopkins Inlet, which contains the largest breeding concentration of harbor seals in Alaska, with an estimated 5,000 to 7,000 seals! They are attracted to the safety of the iceberg-choked inlet where they can haul out on bergs, give birth, and nurture their pups..
The largest member of the weasel family, but the smallest marine mammal, the sea otter is built for swimming at sea with its long, flat tail and webbed hind feet. The retractable claws on their front paws do not assist them in swimming, but rather are used for foraging and grooming their dense fur. Having a round head with small eyes, a triangular nose, visible ear pinnae, and an extensive, overgrown mustache gives one the impression of a little, old man floating at sea. This impression is further perfected as their head and neck becomes bleached out with age; turning white in old animals. Younger adults have a body coloration that ranges from dark brown to blond with the head being lighter in color. The size of an adult male is typically 5 feet in length and 70 pounds in weight. Females are slightly smaller, weighing 60 pounds and measuring 4 feet in length, on average.
Sea Otters in the Tracy Arm Fjords
Sea otters are most commonly encountered in the Kenai Fjords National Park, in Prince William Sound, in Glacier Bay, Tracy Arm Fjord and throughout the Inside Passage. Hundreds may be seen holding hands, floating together in a sex-segregated "raft," while resting. Currently their populations are increasing, numbering approximately 150,000 in Alaskan waters, and sea otters have reoccupied much of their historical range.
Harbor Seal in Glacier Bay National Park
Humpback whales are frequently observed performing their high-energy display of catapulting their forty-seven-foot, thirty-ton bodies almost completely out of the water. This spectacular leaping display, known as breaching, is an incredible, awe-inspiring sight. These aquatic acrobats may also be seen flapping their long flippers on the surface of the water in a manner that could almost be construed as waving at you. Female humpbacks also use their flippers to caress their calves. When a whale shows its flukes, as if to signal goodbye, it usually means that it is going to make a long, deep dive for up to 20 minutes to a half-hour.
The Taz Boat out of Gustavus -Humpback Whales in Icy Straits