Three main groups of marine mammals are found in Prince William Sound: Whales and porpoises; seals and sea lions; and the sea otter. Brief highlights of their natural history are given below; for more detailed information, please see the "Further Reading" list below. Unless noted otherwise, photos on this page taken and copyright by SEA.
Whales and porpoises belong to the animal Order Cetacea (from the Latin wordCetus, whale), and are the most aquatic of the Sound's marine mammals. The most common cetaceans found in Prince William Sound are killer whales, or Orcas, humpback whales, and Dall's and harbor porpoises. Other whales to look for are minke, pilot, and occasionally gray and fin whales.
|
|
|
|
"Transient" Orcas, in contrast, move in and out of the Sound from
other areas, they eat marine mammals exclusively, they occur in smaller
groups, and they are quieter than residents. Transients often cruise
close to shorelines, looking for unwary harbor seals and sea otters.
Whale biologists have catalogued over 300 individual Orcas in the Sound, based on the distinctive shape and markings on their dorsal fins and the "saddle" area directly behind the dorsal fin.
|
|
Photo at right, taken during one of our whale watching trips in May 2002, courtesy of Ken Wesnaes of Scotland. |
|
|
Dall's and harbor porpoises are found throughout much of the Sound. Dall's usually travel in groups of up to 6 - 8, and they often approach moving boats to play in its wake. They can be identified at some distance by their characteristic crescent-shaped spray pattern when they surface, and once close to a boat, their black and white dorsal fin separates them from harbor porpoises. The latter are very shy, and are often solitary. Usually, the only thing one sees of a harbor porpoise is a brief glimpse of their dark back, bent in a wedge shape when they surface to blow. |
|
Sea lions are distinguished from seals by their small external ears and their ability to rotate their rear flippers forward. Harbor seals' ears are small holes on the sides of their head, and they cannot rotate their rear flippers. |
|
|
Harbor seals are found throughout the Sound. They concentrate
on icebergs near tidewater glaciers, which they use as floating
haulouts, and at several island rookeries. Some females use icebergs
for bearing young, but biologists do not yet know the relative
importance of this habitat and land-based rookeries. The Sound's harbor
seals are quite mobile, and move freely back and forth between glacier
ice and their island haulouts. In spring of 1997, biologists counted
1,300 seals on the ice above the impassable (to boats) moraine reef in
front of Columbia Glacier.
Mother harbor seal and newborn pup, College Fjord, June 6, 1999. (SEA photo) |
Increased boat traffic near tidewater glaciers has conservationists keeping a watchful eye on their influence to marine wildlife. Current studies of wildlife-boat interactions by the National Park Service in Glacier Bay and Kenai Fjords will help conservationists assess the situation in Prince William Sound. Preliminary evidence suggests that kayakers and small pleasure boats may unwittingly be disturbing seals and other wildlife more than bigger boats.
| Sea otters are the largest members of the weasel family. They are found throughout Prince William Sound, with the largest concentrations in the southeastern sector. Near tidewater glaciers, they often haul out on small icebergs like harbor seals do. Breeding males tend to be solitary, while females and young of both sexes are more social, sometimes forming "rafts" of 100's of animals. Sea otters were nearly exterminated by fur hunters by the late 1800's, but their populations rebounded after protection in 1911. Their population in the Sound is currently healthy and growing. |
|
Whales and Porpoises / Seals and Sea Lions / Sea Otter
Marine Birds / Land Mammals / Glaciers / Home /