Spotted seals are members of the “true seal” family, Phocidae. They have a round head, narrow snout, small body, and narrow, short flippers. Their coat is silver to light gray with dark spots covering the entire body. They grow to average lengths of 5 ft (1.5 m) with weights ranging from 140-250 lbs (65-115 kg). There are few differences in size, shape, and coloration between males and females. Spotted seals are sometimes confused with harbor seals in areas where their distributions overlap, such as in Bristol Bay, Alaska.
Spotted seals reach sexual maturity around 4 years old. Breeding season ranges from January to mid-April with a peak of pup births in mid-March. Males are thought to be annually monogamous and form “family” groups consisting of a female, male, and a pup during breeding season. Gestation lasts for just over 10 months, and pups are weaned around 6 weeks. Their maximum lifespan is 30 to 35 years.
Spotted seals feed on a variety of prey and diet composition varies by age. Adults mainly feed on herring, arctic cod, pollock, and capelin while juveniles feed mainly on krill and small crustaceans. While feeding, spotted seals dive to depths up to 1,000 ft (300 m).
|140-250 pounds (65-115 kg)|
|5 feet (1.5 m)|
|silver to light gray with dark spots|
|30-35 years; sexually mature at 4 years old|
|adults: herring, arctic cod, pollock, and capelin
juveniles: krill and small crustaceans
|While feeding, spotted seals dive to depths up to 1,000 ft (300 m)!|
Spotted seals prefer arctic or sub-arctic waters and are often found within the outer margins of shifting ice floes. Rarely do they inhabit areas of dense pack ice. During breeding season, spotted seals haul out on ice floes, whereas during the summer months they can be found in the open ocean or hauled out on shore.
The spotted seal occurs in the waters of the North Pacific Ocean. They range from the coast of Alaska throughout the Bering Sea, Sea of Japan, and Sea of Okhotsk.
There is only one recognized stock of spotted seals in U.S. waters, the Alaska stock. The most recent stock assessment reports with population estimates are available on our website.
Loss of sea ice is a potential threat to the habitat of spotted seals. Bycatch in fishing gear, such as groundfish trawls, may occur, but annual mortality of spotted seals incidental to fishing is very low. Additionally, spotted seals are incidentally entangled in salmon trap nets off of the Nemuro Peninsula in Japan.
Spotted seals are considered Low Risk-least concern on the IUCN Red List . On March 28, 2008, NMFS initiated a status review for bearded, ringed, spotted, and ribbon seals to determine if listing these ice seal species under the ESA is warranted. In October 2010, NMFS listed the Southern DPS of spotted seals, in areas of China and Russia, as threatened.
On October 20, 2009, NMFS proposed to designate three Distinct Population Segments (DPSs) of spotted seals.
- The Southern DPS was listed as threatened [pdf] under the ESA on October 22, 2010. The Southern DPS consists of breeding concentrations in the Yellow Sea and Peter the Great Bay in China and Russia.
- The Sea of Okhotsk DPS consists of breeding populations in the Tatar Strait and the Sea of Okhotsk. NMFS found this DPS not warranted for listing under the ESA.
- The Bering Sea DPS, the only DPS that occurs in U.S. waters, consists of breeding concentrations in Karaginsky Bay, the Gulf of Anadyr, and the Bering Sea. NMFS found this DPS not warranted for listing under the ESA.
This species is protected under the Marine Mammal Protection Act of 1972 as amended.
Spotted seals are a subsistence species and are harvested annually by Alaska Natives.
· Spotted seals range from Alaska to Japan and live mostly in pack-ice habitats.
· They give birth on pack ice and form “family” groups consisting of a female, a male, and a pup during breeding season.