Ringed Seal: Wikis

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Ringed Seal
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Phocidae
Genus: Pusa
Species: P. hispida
Binomial name
Pusa hispida
(Schreber, 1775)
Synonyms
Phoca hispida

The ringed seal (Pusa hispida), also known as the jar seal and as netsik or nattiq by the Inuit, is an earless seal inhabiting the northern coasts.

Ringed Seal
backflippers

Contents

Description

The ringed seal is the smallest and most common seal in the Arctic. They have a small head, short cat-like snout, and a plump body. Their coat is dark with silver rings on their back and sides with a silver belly, from which this seal gets its vernacular name. Their small foreflippers have claws more than 1 inch (2.5 cm) thick that are used to maintain breathing holes through 6.5 ft (2 m) thick ice.[2] Ring seals have a small head and small plump bodies. Their snouts are short and narrow.

They grow to average lengths of 5 ft (1.5 m) with weights ranging from 110-150 lbs (50-70 kg).[2]

Range and habitat

Ringed Seal emerging from under the ice

Ringed seals occur throughout the Arctic Ocean. They can be found in the Baltic Sea, the Bering Sea and the Hudson Bay. They prefer to rest on ice floe and will move farther north for denser ice. One subspecies can be found in freshwater.

Ringed seals have a circumpolar distribution from approximately 35°N to the North Pole, occurring in all seas of the Arctic Ocean. In the North Pacific, they are found in the southern Bering Sea and range as far south as the Seas of Okhotsk and Japan. Throughout their range, ringed seals have an affinity for ice-covered waters and are well adapted to occupying seasonal and permanent ice. They tend to prefer large floes (i.e., > 48 m in diameter) and are often found in the interior ice pack where the sea ice coverage is greater than 90%. They remain in contact with ice most of the year and pup on the ice in late winter-early spring.[3]

Distribution in Alaska: Ringed seals are found throughout the Beaufort, Chukchi, and Bering Seas, as far south as Bristol Bay in years of extensive ice coverage. During late April through June, ringed seals are distributed throughout their range from the southern ice edge northward. Preliminary results from recent surveys conducted in the Chukchi Sea in May-June 1999 and 2000 indicate that ringed seal density is higher in nearshore fast and pack ice, and lower in offshore pack ice. Results of surveys conducted by Frost and Lowry (1999) indicate that, in the Alaskan Beaufort Sea, the density of ringed seals in May-June is higher to the east than to the west of Flaxman Island. The overall winter distribution is probably similar, and it is believed there is a net movement of seals northward with the ice edge in late spring and summer. Thus, ringed seals occupying the Bering and southern Chukchi Seas in winter apparently are migratory, but details of their movements are unknown.[3]

Ringed seals reside in arctic waters and are commonly associated with ice floes and pack ice.[2] The ringed seals are the only pinnipeds that maintain a breathing hole in the ice thus allowing it to use ice habitat that other seals cannot.

Life history

Pup of Ringed Seal.

Females reach sexual maturity at 4 years while males do not reach maturity until 7 years old.[2] Males are thought to be monogamous breeders. During the spring breeding season, females construct lairs within the thick ice and give birth in these structures. Females give birth to a single pup on ice floes or shorefast ice in March or April after a 9 month gestation period. Pups are weaned after one month[2] and build up a thick layer of blubber.

Females usually begin mating in late April.[2] Males will roam the ice for a mate. When found, the male and female may spend several days together before mating. Then the male looks for another mate.

Ringed seals live about 25 to 30 years.[2] They are solitary animals and when hauled out on ice separate themselves from each other by hundreds of yards.[2]

The seal's natural predators are orcas, polar bears, wolves and wolverines, and Arctic Fox which prey on the young; in fact, the Ringed Seal is a preferred and important subsistence food for the threatened polar bear.[4]

Diet

Ringed seals eat a wide variety of small prey that consists of 72 species of fish and invertebrates. Feeding is usually a solitary behavior and their prey of choice includes mysids, shrimp, arctic cod, and herring. While feeding, ringed seals dive to depths of 35 to 150 ft (10-45 m).[2]

In the summer ringed seals feed along edge of the sea-ice for polar cod. In shallow water they feed on smaller cod. Ringed seals may also eat herring, smelt, whitefish, sculpin, perch, and crustaceans.

Population

The estimated population size for the Alaska stock of ringed seals is 249,000 animals.[2] Currently, the population trend for this stock is unknown.[2]

Economic importance

Preparation of the Ringed Seal
fur skin of the Ringed Seal.

Examination of Early Paleoeskimo sites in Arctic Canada has demonstrated the deliberate hunting of juvenile and young adult ringed seals, probably in the fall and winter from frozen cracks and leads in the ice.[5]

Threats

Ringed seals are harvested annually by Artic natives for subsistence.[2] Bycatch in fishing gear, such as commercial trawls, is also another threat to ringed seals.[2] Climate change is potentially the most serious threat to ringed seal populations since much of their habitat is dependent upon pack ice.[2] Birthing lairs are often destroyed before the seal pup is able to forage on its own leading to poor body condition.[citation needed]

Conservation status

Ringed seals are considered least concern in the IUCN Red List.[1]

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In the USA

This species is protected under the Marine Mammal Protection Act of 1972 as amended.[2] Ringed seals are not listed as “depleted” under the Marine Mammal Protection Act or listed as “threatened” or “endangered” under the Endangered Species Act.[3] Reliable estimates of the minimum population, potential biological removal, and human-caused mortality and serious injury are currently not available.[3] Because the potential biological removal for ringed seals is unknown, the level of annual U.S. commercial fishery-related mortality that can be considered insignificant and approaching zero mortality and serious injury rate is unknown.[3] No information is available on the status of ringed seals.[3] Due to a very low level of interactions between U.S. commercial fisheries and ringed seals, the Alaska stock of ringed seals is not considered a strategic stock.[3]

On March 28, 2008, the U.S. National Marine Fisheries Service initiated a status review[6] under the Endangered Species Act (ESA) to determine if listing this ice seal species under the ESA is warranted.

Subspecies

The populations living in different areas have evolved to separate subspecies, which are:

The three last subspecies are isolated from the others, like the closely related Baikal Seal (Nerpa) and Caspian Seal.

See also

References

This article incorporates public domain work of the United States Government from references [2][3].

  1. ^ a b Kovacs, K., Lowry, L. & Härkönen, T. (2008). Pusa hispida. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 29 January 2009. Database entry includes justification for why this species is of least concern
  2. ^ a b c d e f g h i j k l m n o p PD-icon.svg Office of Protected Resources - NOAA Fisheries. "Ringed Seal (Phoca hispida)". accessed 11 March 2010.
  3. ^ a b c d e f g h PD-icon.svg Angliss R. P. & Outlaw R. B. (Revised 15 May 2006) "Ringed Seal (Phoca hispida): Alaska Stock". "Alaska Marine Mammal Stock Assessments". NOAA Technical Memorandum AFSC 168: 51-55.
  4. ^ C. Michael Hogan (2008) Polar Bear: Ursus maritimus, globalTwitcher.com, ed. Nicklas Stromberg
  5. ^ Murray, M. S. (2005). "Prehistoric Use of Ringed Seals: A zooarchaeological Study from Arctic Canada". Environmental Archaeology 10 (1): 19-38
  6. ^ (28 March 2008). "Proposed Rules". Federal Register 73(61).

External links


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