Mammal Species of the World
- Original description: Pallas, P.S., 1811. Zoographia Rosso-Asiatica, 1:113.
Spotted seals can be found throughout the North Pacific and on the east coast of Asia. They are common in the Bering, Chukchi, Beaufort, and Okhotsk Seas where they prefer to remain over the continental shelf. They can also be found in the Sea of Japan and the Yellow Sea. Three population groups (Distinct Population Segments, or DPSs) of spotted seals are recognized based on location: the Southern DPS, the Sea of Okhotsk DPS, and the Bering Sea DPS.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); arctic ocean (Native ); pacific ocean (Native )
- 2010. "Spotted Seal (Phoca largha)" (On-line). Accessed December 11, 2012 at http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/spottedseal.htm.
- National Oceanic and Atmospheric Administration. Status Review of the Spotted Seal (Phoca largha). NMFS-AFSC-200. Springfield, VA: Department of Commerce. 2009.
occurs (regularly, as a native taxon) in multiple nations
Global Range: Po Hai Sea, coastal waters of Korea, Sea of Japan, coastal waters of Hokkaido and Honshu, Sea of Okhotsk, Kamchatka, Commander Islands, Bering Sea, Chukchi Sea, eastern Aleutian Islands. In Alaska, breeds in southeastern Bering Sea. In the Bering Sea, the greatest densities occur in winter in spring within approximatelly 25 km of the irregular and shifting southern margin (front) of the pack ice, where breeding and birthing occur (Reeves et al. 1992). Central Bering Sea stock occurs in winter and spring south of Cape Navarin to St. Matthew Island, dispersing into Anadyr Gulf. Eastern Bering Sea stock is centered in the southeastern Bering Sea from the Pribilofs to outer Bristol Bay and disperses northward through Bering Strait and along the shores of the Chukchi Sea. About 2000 occupy Kasegaluk Lagoon near Point Lay, Alaska, from July to freeze-up each year (Reeves et al. 1992).
Pups are born with a dense white coat called a lanugo. The lanugo is normally shed at 2 to 4 weeks of age, giving way to a smooth grey-white coat with dark spots. Juveniles sometimes have a dark dorsal stripe that gradually fades into more spotting as they age. Spotted seals are of a medium size and build. Female adults weigh from 65 to 115 kg and grow to lengths of 151 to 169 cm while male adults typically weigh from 85 to 110 kg with lengths of 161 to 176 cm. Spotted seals share several distinguishing characteristics with all seals, such as lack of an external ear, a streamlined body, and a thick layer of blubber. Their hind flippers are fixed behind them and cannot be turned forward as in members of the family Otariidae (sea lions and fur seals). Spotted seals are very similar in appearance to light-colored harbor seals (Phoca vitulina) and, for a time, they were considered a subspecies of harbor seal. However, harbor seal pups lose their lanugo coat while still in the womb and there are also several skeletal and cranial characteristics that differ considerably between harbor and spotted seals. These and several behavioral differences led to the spotted seal eventually being recognized as a separate species.
Range mass: 65 to 115 kg.
Range length: 151 to 176 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
- Berta, A. 2009. Encyclopedia of Marine Mammals. San Diego: Academic Press.
- Lowry, L., K. Frost, R. Davis, D. DeMaster, R. Suydam. 1998. Movements and behavior of satellite-tagged spotted seals (Phoca largha) in the Bering and Chukchi Seas. Polar Biology, 19/4: 221-230.
Length: 170 cm
Weight: 136 grams
Size in North America
Range: 1.4-1.7 m
Range: 81-109 kg
Catalog Number: USNM 83447
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Sex/Stage: Male; Young adult
Preparation: Skull; Partial Skeleton
Collector(s): L. Stejneger
Year Collected: 1896
Locality: Avatcha Bay, Kamchatskiy, Russia, Bering Sea, Asia, North Pacific Ocean
- Type: Allen, J. A. 12 Dec 1902 . Bulletin of the American Museum of Natural History. 16: 483.
Spotted seals are a pagophilic (ice-loving) species. They reside on sea ice through late autumn and winter while breeding and whelping, moving to nearshore and onshore environments during spring through early autumn. They prefer to remain near the ice front where ice floes are smaller and the water is relatively shallow. They are rarely found far into the ice pack or out in the open ocean.
Habitat Regions: polar ; saltwater or marine
Terrestrial Biomes: icecap
Aquatic Biomes: pelagic ; coastal
- Lowry, L., V. Burkanov, K. Frost, M. Simpkins, R. Davis, D. DeMaster, R. Suydam, A. Springer. 2000. Habitat use and habitat selection by spotted seals (Phoca largha) in the Bering Sea. Canadian Journal of Zoology, 78/11: 1959-1971.
- Simpkins, M., L. Hiruki-Raring, G. Sheffield, J. Grebmeier, J. Bengston. 2003. Habitat selection by ice-associated pinnipeds near St. Lawrence Island, Alaska in March 2001. Polar Biology, 26/9: 577-586.
Habitat and Ecology
In spring, spotted seals give birth to a single pup, mostly on the surface of sea ice but sometimes on land. Pups are born in a white lanugo coat that is shed at or before weaning which occurs about four weeks after birth. Mating occurs after pups are weaned. Spotted seals are annually monogamous and males defend lactating females on ice floes, and groups composed of a female with her pup and a male, called triads, are common during the breeding season (Quakenbush 1988).
In late-spring and summer many spotted seals leave the sea ice and haul-out on land to rest when they are not foraging. On some haulouts in Kamchatka the number of animals on shore may reach over 10,000 individuals (V. Burkanov pers. comm.). As sea ice reforms in October-November spotted seals again use the ice as their primary feeding and resting habitat (Burkanov 1990, Lowry et al. 1998, 2000). They are generalist feeders that take primarily a variety of fish species (walleye pollock, Arctic and saffron cod, rockfish, herring, sand lance, smelt, capelin, eelpout, salmonids and flounders), cephalopods (squid and octopus) and crustaceans (shrimp and crab) (Quakenbush 1988, Burkanov 1990).
Reported predators include Pacific sleeper sharks, killer whales, golden eagles, Steller’s sea eagles, ravens, gulls, polar and brown bears, wolves, Arctic foxes, walruses and Steller sea lions (Quakenbush 1988).
Habitat Type: Marine
Comments: Littoral distribution in summer when shorefast ice has melted. Occurs in estuaries and embayments in late summer and fall. Offshore along edge of ice pack in winter; rarely more than 100 km from pack ice edge. Rests ashore on tide exposed rocks and (in winter) on ice floes. During open-water season, often hauls out on sandbars and beaches. Young are born on ice, where they remain until they are weaned at three to four weeks of age (Perry, in Wilson and Ruff 1999).
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Migrates between summer littoral habitat and offshore winter habitat along edge of ice pack; compass direction and timing of migration varies regionally (Bigg 1981).
Fish are the primary component of the spotted seal's diet, most commonly herring (Clupea pallasii pallasii), pollock (Theragra chalcogramma), cod (Gadus macrocephalus), and capelin (Mallotus villosus). They also feed on mollusks and crustaceans. The pelagic zone of the ocean is where they spend most of their foraging time. The spotted seal's seasonal movements between sea ice and shore is believed to be partially driven by migration of these prey species.
Animal Foods: fish; mollusks; aquatic crustaceans
Primary Diet: carnivore (Piscivore )
- Dehn, L., G. Sheffield, E. Follmann, L. Duffy, D. Thomas, T. O'Hara. 2007. Feeding ecology of phocid seals and some walrus in the Alaskan and Canadian Arctic as determined by stomach contents and stable isotope analysis. Polar Biology, 30/2: 167-181.
Comments: Young eats mainly small crustaceans, including amphipods, shrimps, and euphausiids. Older seals feed opportunistically on various fishes (e.g., walleye pollock, capelin, arctic cod, saffron cod, sand lance, herring, and rainbow smelt), and some cephalopods and crustaceans. Feeds during day; occurrence of night feeding uncertain. (Bigg 1981).
Spotted seals mainly feed in the pelagic zone of the ocean, where their primary prey is schooling fish. Depredation by seals has been shown to have an effect on populations of fish, but there has been no study done that definitively shows the role spotted seals play in the population changes of their prey species. Spotted seals are not thought to be important prey for any other species besides some humans that hunt them for subsistence.
Predators known to occasionally prey on spotted seals include sharks, killer whales, walruses, sea lions, polar bears, brown bears, wolves, several species of birds, and, of course, humans. Spotted seals, however, do not constitute a significant portion of any of these predator's diets. They avoid predation by gathering at haul-out areas, being cryptically colored, and being agile in the water.
- sharks (Chondrichthyes)
- killer whales (Orcinus orca)
- walruses (Odobenus rosmarus)
- Steller's sea lions (Eumetopias jubatus)
- polar bears (Ursus maritimus)
- brown bears (Ursus arctos)
- wolves (Canis lupus)
- birds of prey (Accipitridae)
Anti-predator Adaptations: cryptic
This list may not be complete but is based on published studies.
Known prey organisms
This list may not be complete but is based on published studies.
10,000 to >1,000,000 individuals
Comments: Bering-Chukchi population probably is at least 200,000; Sea of Okhotsk population perhaps 130,000 (Reeves et al. 1992).
Generally solitary in water but forms small groups when ashore (nonbreeding season). All ages congregate for molt after breeding.
Greatest densities occur along the southern edge of the pack ice in the pupping and mating season of late winter and spring. Family groups consisting of an adult female, adult male, and pup are spaced about 200 meters apart (Perry, in Wilson and Ruff 1999).
Taken by various predators, but none of these is known to be a significant influence on population size.
Life History and Behavior
Olfaction is believed to be extremely important in maintaining relationships between individuals, especially between mates and between mothers and their offspring. One of the most important reasons for the gathering of many spotted seals at haul-out sites is so this olfactory (as well as tactile) contact can occur between individuals. If a mother and offspring are separated, they will call to each other and touch noses once reunited. Calling and nosing have also been observed between mating pairs. When navigating under ice, spotted seals rely mostly on vision, then on auditory and tactile cues.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
- Elsner, R., D. Wartzok, N. Sonafrank, B. Kelly. 1989. Behavioral and physiological reactions of arctic seals during under-ice pilotage. Canadian Journal of Zoology, 67/10: 2506-2513.
About 45% of spotted seal pups die within their first year of life. If they survive to adulthood, they can live to a maximum of 30 to 35 years of age.
Status: wild: 35 (high) years.
Status: wild: 32.0 years.
Status: wild: 35.0 years.
Status: wild: 32.0 years.
Status: wild: 29.0 years.
Lifespan, longevity, and ageing
Spotted seals are unusual among seals in that they are annually monogamous rather than polygynous. Mating pairs form when the female is about to give birth to a pup from the previous year’s mating. The pair remain together until that pup weans and the female goes into oestrus and will copulate once again. Mating occurs underwater and copulation is preceded by increased vocalizations and physical contact, such as nosing. Mating pairs tend to form a small group of two or three individuals depending on if there is a pup present or not.
Mating System: monogamous
Female spotted seals reach sexual maturity when they are 3 to 4 years old. Males usually take 4 to 5 years before maturing. Breeding is normally in the spring, around April or May, but can occur as early as January in Asian waters. A single pup is born the following spring. Gestation lasts 7 to 9 months, but a delay in implantation of the blastocyst after breeding can extend the length of the entire pregnancy to almost a year. Pups are weaned after 2 to 4 weeks, when their lanugo is shed and they can leave the ice to begin learning to forage for themselves in the water.
Breeding interval: Spotted seals breed once yearly.
Breeding season: Breeding occurs from January to May, depending on the location.
Average number of offspring: 1.
Range gestation period: 7 to 12 months.
Range weaning age: 2 to 4 weeks.
Range time to independence: 2 to 4 weeks.
Range age at sexual or reproductive maturity (female): 3 to 4 minutes.
Range age at sexual or reproductive maturity (male): 4 to 5 minutes.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; delayed implantation
Average birth mass: 7100 g.
Average number of offspring: 1.
Pups nurse for 2 to 4 weeks after birth. Both the mother and her current mate remain with the pup during this time. The male probably doesn’t contribute much to the pup’s care since it is not his, but mostly focuses on being near the female. Once the pup has been weaned (at about a month old), it is abandoned by the mother and left to fend for itself. Female spotted seals have been observed adopting strange pups if they are separated from their own.
Parental Investment: precocial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
- National Oceanic and Atmospheric Administration. Status Review of the Spotted Seal (Phoca largha). NMFS-AFSC-200. Springfield, VA: Department of Commerce. 2009.
- Atkinson, S. 1997. Reproductive biology of seals. Reviews of Reproduction, 2/3: 175-194.
- Beier, J., D. Wartzok. 1979. Mating behavior of captive spotted seals (Phoca largha). Animal Behavior, 27/3: 772-781.
- Burns, J., C. Ray, F. Fay, P. Shaughnessy. 1972. Adoption of a strange new pup by the ice-inhabiting harbor seal Phoca vitulina largha. Journal of Mammalogy, 53/3: 594-598.
- Rugh, D., K. Sheldon, D. Withrow. 1997. Spotted seals (Phoca largha) in Alaska. Marine Fisheries Review, 59: 1-18.
Pairs form about 10 days before pupping, stay together (and away from other pairs) until mating about 1 month later. Gestation lasts 10.5 months, including a period of 1.5-4 months of delayed implantation. In Alaska, most births occur late March to mid-May. In Japan, births occur from late January to mid-April, with a peak in the second half of March. Lactation lasts 2-6 weeks (estimated at 2-3 weeks in Japan). Females sexually mature at 3-4 years, males at 4-5 years.
Molecular Biology and Genetics
Barcode data: Phoca largha
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Phoca largha
Public Records: 5
Specimens with Barcodes: 7
Species With Barcodes: 1
With climate change resulting in a reduction in the area of sea ice, there is concern for populations of spotted seals as well as other polar marine species as they face possible changes in habitat and prey distribution. Spotted seals are also victims of fishing bycatch and poaching. At this time the species is considered to be data deficient by the IUCN. Only the Southern DPS of spotted seals was listed as Threatened under the Endangered Species Act in 2010 by the National Marine Fisheries Service. This was due to reports of decreasing populations on Asian coasts.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: data deficient
- Bluhm, B., R. Gradinger. 2008. Regional variability in food availability for arctic marine mammals. Ecological Applications, 18/2: S77-S96.
- Won, C., B. Yoo. 2004. Abundance, seasonal haul-out pattern and conservation of spotted seals (Phoca largha) along the coast of Bak-ryoung Island, South Korea. Oryx, 38/1: 109-112.
IUCN Red List Assessment
Red List Category
Red List Criteria
IUCN Evaluation of the Spotted Seal, Phoca largha
Prepared by the Pinniped Specialist Group
A. Population reduction Declines measured over the longer of 10 years or 3 generations
A1 CR > 90%; EN > 70%; VU > 50%
Al. Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction are clearly reversible AND understood AND have ceased, based on and specifying any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality
(d) actual or potential levels of exploitation
(e) effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
Age-structure data are not available for the Spotted Seal population so the generation time cannot be calculated precisely. With sexual maturity attained at 3-5 years of age and a maximum longevity of approximately 35 years, the average age of reproducing individuals should be at least 10 years. A population reduction of Sotted Seals has not been observed, estimated, inferred, or suspected in the past 30 years. However, population abundance is poorly known and has not been monitored.
A2, A3 & A4 CR > 80%; EN > 50%; VU > 30%
A2. Population reduction observed, estimated, inferred, or suspected in the past where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
A population reduction of spotted seals has not been observed, estimated, inferred, or suspected in the past 30 years.
A3. Population reduction projected or suspected to be met in the future (up to a maximum of 100 years) based on (b) to (e) under A1.
A population reduction of Spotted Seals is suspected in the future because of predicted reduction in sea ice habitats due to continued climate warming. The likely amount of population reduction has not been projected, but could exceed 30% within the next 30 years. This meets the criterion for Vulnerable.
A4. An observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
A population reduction of Spotted Seals has not been observed, estimated, inferred, or suspected in the past 30 years.
B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
B1. Extent of occurrence (EOO): CR < 100 km²; EN < 5,000 km²; VU < 20,000 km²
The EOO of Spotted Seals is > 20,000 km².
B2. Area of occupancy (AOO): CR < 10 km²; EN < 500 km²; VU < 2,000 km²
The AOO of Spotted Seals is > 2,000 km².
AND at least 2 of the following:
(a) Severely fragmented, OR number of locations: CR = 1; EN < 5; VU < 10
(b) Continuing decline in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals.
(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals.
C. Small population size and decline
Number of mature individuals: CR < 250; EN < 2,500; VU < 10,000
The current abundance of Spotted Seals is poorly known, but the number of mature individuals is certainly > 10,000.
AND either C1 or C2:
C1. An estimated continuing decline of at least: CR = 25% in 3 years or 1 generation; EN = 20% in 5 years or 2 generations; VU = 10% in 10 years or 3 generations (up to a max. of 100 years in future)
C2. A continuing decline AND (a) and/or (b):
(a i) Number of mature individuals in each subpopulation: CR < 50; EN < 250; VU < 1,000
(a ii) % individuals in one subpopulation: CR = 90–100%; EN = 95–100%; VU = 100%
(b) Extreme fluctuations in the number of mature individuals.
D. Very small or restricted population
Number of mature individuals: CR < 50; EN < 250; VU < 1,000 AND/OR restricted area of occupancy typically: AOO < 20 km² or number of locations < 5
The current abundance of Spotted Seals is poorly known, but the number of mature individuals is certainly > 1,000. AOO is > 20 km² and the number of locations is > 5.
E. Quantitative analysis
Indicating the probability of extinction in the wild to be: CR > 50% in 10 years or 3 generations (100 years max.); EN > 20% in 20 years or 5 generations (100 years max.); VU > 10% in 100 years
There has been no quantitative analysis of the probability of extinction for Spotted Seals.
Listing recommendation — Past, poorly documented, estimates of Spotted Seal abundance suggest a total population size of perhaps 400,000. Based on reports from coastal Alaskan hunters, Spotted Seals are still numerous and no major changes in abundance have been reported. However, climate warming and reduction in sea ice coverage are occurring, and because most Spotted Seals depend on sea ice for reproduction that will likely result in a population decline. Current abundance and population trend are unknown, and thus the Spotted Seal must be classified as Data Deficient at this time.
- 1996Lower Risk/least concern(Baillie and Groombridge 1996)
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Female spotted seals become sexually mature at 3-4 years old and males at 4-5 years. Maximum longevity is at least 35 years (Quakenbush 1988).
Global Short Term Trend: Relatively stable (=10% change)
Comments: World population is regarded as essentially stable (Reeves et al. 1992). Total population probably near historical level (Bigg 1981).
Intensive harvesting of fish in the Okhotsk and Bering seas poses a risk to spotted seals as several of their main prey species are targets of commercial fisheries (Lowry and Frost 1985). Entanglement in commercial fisheries occurs occasionally in Japan and in the Sea of Okhotsk and Bering Sea and small organized control kills to limit damage to fisheries regularly occur in Japan (Mizuno et al. 2001, Angliss and Outlaw 2007). In Kamchatka, spotted seals sometimes eat fish out of fishing gear and fishermen shoot small numbers in local areas to defend their landings and protect their equipment (V. Burkanov pers. comm.).
Oil and gas development may cause disturbance to and adversely affect the habitat used by the spotted seals (Reijnders et al. 1993). Oil contamination poses poorly known risks to spotted seal populations. The greatest impacts would likely result if spills occurred during the pupping season, if food resources were negatively effected or if the spill was an event that affected a large area (St Aubin 1990). There is little information on contaminant burdens in this species, but concern would be greatest for animals living in the western part of the range where they occur near large population and industrial areas in China, Korea and Japan and in the Sea of Okhotsk.
Reduction in late winter and spring sea ice cover in the Sea of Okhotsk and the central and southern Bering Sea as a result of global climate change could be problematic for spotted seals as the majority of the population uses pack ice at the southern limit of the ice extent for pupping (Tynan and DeMaster 1997). Changes to ice characteristics that effect its location, timing, stability, etc. could result in lower survival of spotted seal pups. Disruption or alteration of the patterns of primary productivity and abundance of key prey species could also have detrimental effects on ice dependent seals like the spotted seal (Tynan and DeMaster 1997; Laidre et al., in press).
Comments: Intensive commercial fisheries for pandalid shrimps, pollock, and herring in the southern Bering Sea may threaten seals' food supply. Oil and gas exploration, extraction, and transport activities under way or scheduled in portions of winter range may impact seals or their food resources (Reeves et al. 1992).
Commercial harvesting of spotted seals from vessels of the Russian Federation ended in 1994. Small scale commercial and subsistence harvest from small boats and land occurs along the Russian Far East coast, but the size of the harvest is relatively small (V. Burkanov pers. comm.).
Management Requirements: Separate western, central, and eastern stocks have been proposed for management in the Bering Sea (Reeves et al. 1992).
Relevance to Humans and Ecosystems
Spotted seals sometimes take fish from nets.
- Northridge, S. 1991. An updated world review of interactions between marine mammals and fisheries. Rome: Food and Agricultural Organization of the United Nations.
Alaska Natives and some Russian hunters rely on spotted seals as part of their subsistence lifestyle. In addition to using them as food, skins are used for clothing. The annual take of spotted seals isn’t well documented, but the yearly average in Alaska between 1966 and 1976 was estimated at 2,400. Seal oil has gained some popularity as a health supplement for lowering blood pressure.
Positive Impacts: food ; body parts are source of valuable material
- Meyer, B., A. Lane, N. Mann. 2009. Comparison of seal oil to tuna oil on plasma lipid levels and blood pressure in hypertriglyceridaemic subjects. Lipids, 44/9: 827-835.
- Nelson, M. 2008. "Spotted Seal" (On-line). Alaska Department of Fish and Game. Accessed December 11, 2012 at http://www.adfg.alaska.gov/static/education/wns/spotted_seal.pdf.
Comments: A few thousand to several thousand are harvested annually by "Soviet" hunters, to feed animals in fur farms; lately, nearly all of the harvest was made from ships in the Bering Sea. Japanese harvest formerly was more extensive, now occurs only when pack ice approaches coast of Hokkaido. A small subsistence harvest occurs in Alaska.
The spotted seal (Phoca largha, Phoca vitulina largha), also known as the larga or largha seal, is a member of the family Phocidae, and is considered a "true seal". It inhabits ice floes and waters of the north Pacific Ocean and adjacent seas. It is primarily found along the continental shelf of the Beaufort, Chukchi, Bering and Okhotsk Seas and south to the northern Yellow Sea and it migrates south as far as northern Huanghai and the western Sea of Japan. It is also found in Alaska from the southeastern Bristol Bay to Demarcation Point during the ice-free seasons of summer and autumn when spotted seals mate and have pups. Smaller numbers are found in the Beaufort Sea. It is sometimes mistaken for the harbor seal to which it is closely related and spotted seals and harbor seals often mingle together in areas where their habitats overlap.
The reduction in arctic ice floes due to global warming led to concerns that the spotted seal was threatened with extinction. Studies were conducted on its population numbers, with the conclusion, as of October 15, 2009, that the spotted seal population in Alaskan waters is not currently to be listed as endangered by NOAA.
The scientific name originated in the Greek word for seal, phoce, and larga, the term used by the Siberian Tungus people for this seal. The English common name is comes from this seal's characteristic dark, irregularly shaped spots. Alaskan Eskimo names include issuriq (Central Alaskan Yup'ik language), gazigyaq in St. Lawrence Island Yupik, and qasigiaq in Inupiaq.
Spotted seals are inhabitants of arctic or sub-arctic waters, often in the outer areas of ice floes during the breeding season. They tend not to live within dense drift ice. In the summer months they live in the open ocean or on nearby shores.
Spotted seals are separated into three populations. The Bering Sea population includes approximately 100,000 in the western Bering Sea near Kamchatka, in the Gulf of Anadyr in Russia, and in the eastern Bering Sea in Alaskan waters (the only population in the US). A second population of about 100,000 seals breeds in the Sea of Japan and the Sea of Okhotsk. A third population of about 3,300 seals is to the south in Liaodong Bay, China and Peter the Great Bay, Russia. There is also a smaller population of 300 grey spotted seals living in waters off Baekryeong Island located far north of the west coast of South Korea.
The spotted seal is of the family, Phocidae, or "true seals". Compared to other true seals, they are intermediate in size, with mature adults of both sexes generally weighing between 180 to 240 pounds (81 to 109 kg) and measuring 4.59 to 6.89 ft (1.5 to 2.1 meters), roughly the same size as a harbor seal or ribbon seal. The head of a spotted seal is round, with a narrow snout resembling that of a dog.
The spotted seal has a relatively small body and short flippers extending behind the body that provide thrust, while the small flippers in front act as rudders. The dense fur varies in color from silver to gray and white and is characterized by dark, irregular spots against the lighter background and covering the entire body. Males and females differ little in size or shape. In places where their habitat overlaps with that of the harbor seal, they can be confused with them, as in Bristol Bay, Alaska. Like harbor seals, spotted seals have 34 teeth.
Behavior and reproduction
Spotted seals are relatively shy and are difficult for humans to approach. They can be solitary in general but are gregarious and form large groups during pupping and molting seasons when they haul out on ice floes or, lacking ice, on land. The numerically largest groups in Alaska are at Kasegaluk Lagoon in the Chukchi Sea, near Cape Espenburg in Kotzebue Sound, and in Kuskokwim Bay on sandbars and shoals, where several thousand may collect.
Sexual maturity is attained around the age of four. January to mid-April is the breeding season. Pup births peak in mid-March. Spotted seals are believed annually monogamous, and during breeding season, they form "families" made up of a male, female, and their pup, born after a 10 month gestation period. Average birth size is 3 ft (1 m) and 26 lbs. Pups are weaned six weeks later. The maximum lifespan of the spotted seal is 35 years with few living beyond 25.
Spotted seals dive to depths up to 1,000 ft (300 m) while feeding on a variety of ocean prey. Juveniles eat primarily krill and small crustaceans while adults eat a variety of fish including herring, arctic cod, pollock, and capelin. They do not seem to vocalize a lot, although not much is known about their vocalizations. They appear to vocalize more while in molting groups. When approached in these groups, they make various sounds such as growls, barks, moans, and roars.
On March 28, 2008, the U.S. National Oceanic and Atmospheric Administration (NOAA) initiated a status review under the Endangered Species Act (ESA) to determine if listing this ice seal species under the ESA was warranted. After an 18-month review of the status of the spotted seal, NOAA announced on October 15, 2009 that two of the three spotted seal populations, together numbering 200,000 seals in or adjacent to Alaska, are not in danger of becoming extinct, nor are they likely to become so in the "foreseeable future", even though global warming has caused a loss in arctic ice mass. The announcement stated: "We do not predict the expected fluctuations in sea ice will affect them enough to warrant listing at this time."
In South Korea, spotted seals have been designated Natural Monument No. 331 and second-class endangered species. This is because the seals from South Korea travel to Dalian, China to breed every year where several thousands are harvested for their genitals and sealskin to be sold on the black market for Chinese medicine. An environmental activist group Green Korea United is currently working closely with local Chinese government to stop the seals from being poached by Chinese fishermen.
- Lowry, L. & Burkanov, V. (2008). Phoca largha. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 29 January 2009.
- Integrated Taxonomic Information System
- Peter Saundry. 2010. Spotted seal. Encyclopedia of Earth. topic ed. C.Michael Hogan. ed in chief C. Cleveland, National Council for Science and the Environment, Washington DC
- Burns, John J. "Spotted Seal: Wildlife Notebook Series – Alaska Department of Fish and Game". www.adfg.state.ak.us. Retrieved 2009-10-15.
- "National Marine Mammal Laboratory". www.afsc.noaa.gov. Retrieved 2009-10-16.
- "NOAA – National Oceanic and Atmospheric Administration – NOAA Will Not List Bering Spotted Seal as Endangered or Threatened". www.noaanews.noaa.gov. Retrieved 2009-10-15.
- "Spotted Seal (Phoca largha) – Office of Protected Resources – NOAA Fisheries". www.nmfs.noaa.gov. Retrieved 2009-10-15.
- Wynne, Kate. "Spotted (Largha) Seal – Alaska Sea Grant". seagrant.uaf.edu. Retrieved 2009-10-16.
- "Marine Mammals; Advance Notice of Proposed Rulemaking". Federal Register /Vol. 73, No. 61 / Friday, March 28, 2008. Retrieved 2009-10-16.
- Joling, Dan. "Feds deny protection for spotted seals near Alaska – Yahoo! News". The Seattle Times. Retrieved 2009-10-16.
- Green Korea United :: Poaching for 1000 Spotted Seals, Wailing of Spotted Seals. Green-korea.tistory.com. Retrieved on 2011-09-15.
- Kbs News. News.kbs.co.kr (2011-05-24). Retrieved on 2011-09-15.
Names and Taxonomy
Comments: Phoca largha has been treated as conspecific with P. vitulina by some authors; recent accounts generally have regarded vitulina and largha as separate species (e.g., Reeves et al. 1992; Wozencraft, in Wilson and Reeder 1993, 2005; Rice 1998, Baker et al. 2003). This is supported by limited mtDNA data (Mouchaty et al. 1995). See Bigg (1981) for a brief discussion of taxonomy.
A cladistic analysis of mtDNA data yielded three clades among northern seals: Phoca-Pusa-Halichoerus, Cystophora-Pagophilus, and Erignathus (Perry et al. 1995). Each clade may be regarded as a tribe of the subfamily Phocinae. The magnitude of the differences among Phoca, Pusa, and Halichoerus was on the same order as that between species and subspecies within the genus Odocoileus. Because Cystophora is the closest relative of Pagophilus, the latter cannot be regarded as congeneric with Phoca; the differences between the two are great enough to justify placing them in separate genera (Perry et al. 1995).