Local Marine Mammals

 

A variety of marine mammals are residents or seasonal visitors to waters and beaches of eastern Jefferson County. Follow the links below for information about each species.

Steller sea lions
Steller sea lions
orca feeding on porpoise
Gray whale
river otters

River Otters
Seals and Sea Lions
Harbor SealHarbor Seal, Phoca vitulina
Elephant SealNorthern Elephant SealMirounga angustirostris
California Sea LionCalifornia Sea Lion, Zalophus californianus
Stellar Sea LionSteller Sea Lion, Eumetopias jubatus
Porpoises and Whales
Harbor PorpoiseHarbor Porpoise, Phocoena phocoena
Dall's PorpoiseDall's Porpoise, Phocoenoides dalli
Orca whaleKiller Whale, Orcinus orca
minke whaleMinke Whale, Balaenoptera acutorostrata
Gray WhaleGray Whale, Eschrictus robustus
humpback whaleHumpback Whale, Megaptera novaeangliae
Otters
River otterRiver Otter, Lontra canadensis
sea otterSea Otter, Enhydra lutris

SEALS AND SEA LIONS
harbor sealHarbor Seal, Phoca vitulina

Adult Length:
 4-6 ft. 
Adult Weight: up to 300 lbs.
Local sightings: Common year round.

Description: Spotted coat in colors ranging from silver-gray to tan-brown. White whiskers. 

Behavior:
  Adults commonly haul out on beaches during the day to rest, warm their bodies and socialize. Seals can sleep underwater, surfacing every 30 minutes to breathe. Adults are usually wary of humans and enter the water when disturbed. They move with an awkward wriggling motion on land.

Pups are born from June to August in our area and spend 4-6 weeks with their mother before being weaned. Pups are often seen resting on the shore while their mothers feed nearby. The mother seal is wary of humans and will wait to return to her pup until there are no disturbances.
Northern Elephant Seal, Mirounga angustirostris
Elephant seal
Adult Length: Males 12-16 ft., females 7-12 ft. 
Adult Weight: Males to 5000 lbs, females to 2000 lbs. 
Local sightings: 
Infrequently seen spring and summer.

Description: Pups are born with a black coat which turns silvery-gray and then brown as an adult. Males start developing a large, characteristic, elephant-like nose at 3-5 years old. Black whiskers. 

Behavior: They spend up to 90 percent of their lives underwater and can dive to 5000 feet, holding their breath for up to 80 minutes, but they move with an awkward wriggling motion on land.

Each year they come ashore for about a month to molt, sometime between April and August. During this process they shed their fur and upper layer of skin, a process known as “catastrophic molt.” This can appear gruesome (potentially forming scabs and skin lesions) but is completely normal.
California sea lionCalifornia Sea Lion, Zalophus californianus 

Adult length:
 Males 8 ft., females 5 ft. 
Adult weight: Males 800 lbs, females 250 lbs 
Local sightings: Common from fall to spring.

Description:
 Fur ranges in color from dark brown in males to a lighter golden-brown in females. At around 5 years, the males develop a bony bump on the top of their skulls, called the sagittal crest.

Behavior: Very social and playful, frequently seen on piers or buoys, or floating together on the surface in “rafts.” A behavior called “sailing” is common: the animals will hold a motionless flipper out of the water as they float on the surface. This helps them regulate their body temperature. They walk on all four flippers on land.
Steller sea lionSteller Sea Lion, Eumetopias jubatus

Adult Length:
 Males 8.5-11 ft., females 6-7 ft. 
Adult Weight: Males to 2,500 lbs., females to 1000 lbs.
Local sightings: Occasional year round. 

Description:
 
Steller sea lions are much larger and lighter in color than California sea lions. They have light brown to reddish-brown coats. Males do not have a sagittal crest. Classified as a “threatened” species and protected under the Endangered Species Act. 

Behavior:

Generally wary of humans when on land but less cautious when they are in the water. They are often seen leaping or swimming quickly along the surface. When on land they walk on all four flippers. 

There are established breeding colonies in both Oregon and British Columbia but none in Washington State. However, a few pups are born each year on the Washington coast.

PORPOISES AND WHALES
Harbor porpoiseHarbor Porpoise, Phocoena phocoena 

Adult Length
: 5 ft. 
Adult Weight: 135 to 175 lbs .
Local sightings: Common year round.

Description: Gray brown to black on top with a light gray underside. Small, triangular dorsal fin. 

Behavior:
  Usually travel in small groups of 1-6 animals, surfacing with a slow roll and sharp exhale of breath. Prefer shallow coastal waters; generally shy and avoid boats.
Dall's porpoiseDall's Porpoise, Phocoenoides dalli 

Adult Length:
 6 ft. 
Adult Weight: Up to 490 lbs .
Local sightings: Rarely seen year round.

Description: Sometimes mistaken for a "baby orca." 
Black with white markings on flanks and belly, white tip on the dorsal fin and white edging on the tail fluke. Dorsal fin is small, upright, and triangular. Sometimes called "broken tail" because of a distinct kink in the tail stock when diving. 

Behavior:
 Typically seen in groups of 2-20 animals in areas of deep water. Very fast swimmers, often seen racing along the surface creating a "rooster tail" of spray. Known to seek out boats in order to ride the bow waves.
Killer whaleKiller Whale, Orcinus orca 

Adult Length:
 Males to 32 ft., females to 28 ft.
Adult Weight: Males to 22,00 lbs., females to 16,500 lbs.
Local sightings: Occasionally seen year round.

Description: Black on top, white undersides and a white patch near each eye. Each whale also has a unique gray or white “saddle” patch behind the dorsal fin. Dorsal fins reach up to six feet tall on adult males. 

Behavior:
 Usually travel in groups of 5-20 individuals, but can be in larger or smaller groups. Can travel up to 100 miles in one day. At the surface, they commonly breach, spy hop, and/or tail lob.
Gray whaleGray Whale, Eschrictius robustus 

Adult Length:
 39 to 46 ft., 
Adult Weight: 15,000 to 39,000 lbs.
Local sightings: Occasional spring to fall.

Description: A mottled gray color. Instead of a dorsal fin, they have a small dorsal “hump” and a series of 8-14 small bumps called “knuckles” between the hump and the tail flukes. 

Behavior: Feeds on the ocean floor in shallow water (usually 150-400 feet) by rolling onto its side, sucking up sediment, and pressing water and sediment out through the baleen to filter out and eat organisms living in the mud. It is normal to see these whales kicking up sediment while they feed. May occasionally spy hop, breach or tail lob.
Minki whaleMinke Whale, Balaenoptera acutorostrata 

Adult Length:
 About 50 ft. 
Adult Weight: Up to 20,000 lbs.
Local sightings: Rarely seen year round.

Description: The smallest baleen whale in North American waters. Has a dark gray or black body with a white underside, and a fairly tall dorsal fin 2/3 of the way down their back. 

Behavior:
 Usually solitary and the blow is rarely visible. Can be active at the surface, frequently spy hopping and breaching, but does not typically display tail flukes when diving.
Humpback Whale, Megaptera novaeangliae Humpback whale

Adult Length:
 About 52 ft. 
Adult Weight: Up to 90,000 lbs.
Local sightings: Occasional year round.

Description: Large baleen whale with a black to slate gray back and white markings underneath. A small dorsal fin varies from a bump to a sickle-shaped curve. Long pectoral fins are one-quarter the length of the body. 

Behavior:
 Exhale with a large blow that is visible for long distances. Can be very active, often breaching, flipper slapping or tail lobbing.

OTTERS
River otterRiver Otter, Lontra canadensis 

Adult length:
 4.5 ft. 
Adult weight: Up to 35 lbs. 
Local sightings: Commonly seen year round.

Description:
 Long, thin body, short legs and short round ears. Long tail is 1/3 the length of the body. Webbed feet are used for swimming and catching prey.

Behavior: Groups of up to 5 animals, usually a female and her pups. Swim on their bellies and never seen on their backs in the water. Hunt in shallow marine waters and often seen on docks, beaches or rocky shorelines devouring their prey.
Sea otterSea Otter, Enhydra lutris 

Adult length:
 Up to 5 ft. 
Adult weight: Up to 100 lbs.
Local sightings: Rarely seen year round.

Description:
 Brown body with light gray head. Short, stocky tail. Webbed, flipper-like feet.

Behavior: Rarely leave the water. Almost always swim, rest and feed while on their backs.

The marine mammal images on this page are the work of Natural History Illustrator Uko Gorter
Please do not use without permission.