Phoca largha 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Carnivora Phocidae

Scientific Name: Phoca largha
Species Authority: (Pallas, 1811)
Common Name(s):
English Spotted Seal, Larga Seal
Taxonomic Notes: Morphological, reproductive and behavioural differences separate Spotted Seals from their close relatives, the North Pacific Harbour Seals (Phoca vitulina richardii and P. v. stejnegeri) both of whose ranges overlap with the Spotted Seal (Rice 1998). Recent studies of mtDNA confirmed the distinctiveness of the Harbour and Spotted Seals at the species level. The two species have hybridized in captivity, although information on hybrids occurring in the wild is limited to one possible case (O’Corry-Crowe and Westlake 1997). While Shaughnessy and Fay (1977) identified several separate breeding concentrations, the initial, small, genetic samples did not show geographic substructure within the species (O’Corry-Crowe and Westlake 1997). More recent analyses of larger samples indicate possible population structure between the Yellow Sea, the Sea of Okhotsk, and the Bering Sea (Li et al. 2010, O’Corry-Crowe and Bonin 2009, Boveng et al. 2009).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2016
Date Assessed: 2015-06-03
Assessor(s): Boveng, P.
Reviewer(s): Lowry, L.
Facilitator/Compiler(s): Lowry, L., Ahonen, H., Pollock, C.M., Chiozza, F. & Battistoni, A.
The Spotted Seal is an abundant species and there is no evidence of recent declines in the main part of its range. It is therefore listed as Least Concern.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Spotted Seals breed in the Bering Sea, the Sea of Okhotsk, the Sea of Japan, the Yellow Sea, and the Bohia Sea. They are also found outside the breeding season in the Chukchi and Beaufort seas, ranging north into the Arctic Ocean to about the edge of the continental shelf, west to about 170°E longitude, and east to the Mackenzie River Delta in Canada (Shaughnessey and Fay 1977, Quakenbush 1988). They inhabit the southern edge of the pack ice from winter to early summer. In late summer and fall, Spotted Seals move into coastal areas, including river mouths. They rarely occur in water depths greater than 200 m (Lowry et al. 2000). They breed mostly on sea ice and haul-out on sea ice when it is available, but they also haul out on beaches and sandbars (Burns 1970; Lowry et al. 1998, 2000). There are several sites along the Asian coast where Spotted Seals breed on small remote islands (e.g., in Peter the Great Gulf, the Kuril Islands, and small islands along east coast of Kamchatka; Burkanov 1988, 1990; Trukhin and Katin 2001; Kostenko et al. 2004; Vertyankin and Nikulin 2004).
Countries occurrence:
Canada; China; Japan; Korea, Democratic People's Republic of; Korea, Republic of; Russian Federation; United States
FAO Marine Fishing Areas:
Arctic Sea; Pacific – northwest; Pacific – northeast
Additional data:
Estimated area of occupancy (AOO) - km2:2542964Continuing decline in area of occupancy (AOO):No
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:14164188
Continuing decline in extent of occurrence (EOO):NoExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:No
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):3
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The abundance of Spotted Seals has never been well quantified. Poorly documented estimates suggest a total population size in the 1970s of perhaps 400,000, with 200-250,000 in the Bering-Chukchi Seas and perhaps 170,000 in the Okhotsk Sea (Bigg 1981, Quakenbush 1988). More recent surveys indicate the total number may be in excess of 640,000 individuals, with more than 460,000 in the Bering Sea (Conn et al. 2014), 180,000 in the Sea of Okhotsk (Fedoseev 2000), and about 3,300 in the Yellow Sea and Sea of Japan (Han et al. 2010, Nesterenko and Katin 2009). Surveys have been too irregular and imprecise to measure population trend, but Alaska Native hunters have not reported any notable changes in the availability of Spotted Seals (Boveng et al. 2009, Quakenbush et al. 2009).

Maximum longevity is at least 35 years (Quakenbush 1988). Less than a third of females and males become sexually mature by age 3, about two-thirds of both sexes become mature by age 4, and nearly all (i.e., >90%) are sexually mature by age 5 (Tikhomirov 1966, Naito and Nishiwaki 1972, Fedoseev 2000, Boveng et al. 2009).
Current Population Trend:Unknown
Additional data:
Number of mature individuals:320000
Extreme fluctuations:NoPopulation severely fragmented:No
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:In the Bering Sea and Sea of Okhotsk, adult female Spotted Seals usually weigh 65-115 kg and are 151-169 cm long, while adult males weigh 85-110 kg and are 161-176 cm long (Boveng et al. 2009). Maximum reported length was 182 cm for females and 185 cm for males (Tikhomirov 1968).

In spring, Spotted Seals give birth to a single pup, typically on the surface of sea ice but in some places on shore, particularly in the Bohai Sea, Peter the Great Bay, the South Kuril Islands, the second Kuril Strait, Utashud Island, and the east coast of Kamchatka (Trukhin 2005). Pups are born in a white lanugo coat that is shed at or before weaning, which occurs about four weeks after birth. At birth pups are 75-92 cm long and weigh 7-12 kg, and they grow to 30 kg or more by weaning (Boveng et al. 2009). Mating occurs after pups are weaned. Spotted Seals are annually monogamous and males defend lactating females on ice floes. 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 haul-out sites in Kamchatka the number of animals on shore may exceed 10,000 individuals (V. Burkanov pers. comm.). As sea ice forms 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, Salmon, Flatfishes), cephalopods (Squid and Octopus) and crustaceans (Shrimp and Crab) (Burkanov 1990, Quakenbush et al. 2009).

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).
Systems:Terrestrial; Marine

Use and Trade [top]

Use and Trade: Alaska Natives are allowed to take marine mammals for subsistence and creation of handicrafts. Subsistence hunting of Spotted Seals has no doubt occurred since humans first made contact with the species and they remain an important subsistence resource for coastal Alaska Natives in western Alaska (Quakenbush 1988, Allen and Angliss 2014). From the 1960s through the 1980s, the Soviet Union harvested several thousand Spotted Seals each year in both the Okhotsk and Bering seas, mostly from large commercial vessels (Heptner 1996). Commercial harvesting of this species no longer occurs in Russia.

Threats [top]

Major Threat(s): 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. 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 Spotted Seals (Reijnders et al. 1993). Oil contamination poses poorly known risks to their populations, but the closely related North Pacific Harbor Seal was impacted by oil spilled from the tanker Exxon Valdez (Frost et al. 1994). The greatest impacts would likely result if spills occurred during the pupping season, if food resources were negatively affected, or if the spill was an event that affected a large area (St. Aubin 1990). A variety of contaminants have been found in Spotted Seals sampled in Alaska but their potential impacts are largely unknown (Quakenbush et al. 2009). Contaminant concerns 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.

Reduction in late winter and spring sea ice cover as a result of the disrupted, warming climate 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 (e.g., Tynan and DeMaster 1997). Changes to ice characteristics that affect its location, timing, stability, etc. could result in lower survival of Spotted Seal pups. This threat is strongest in the southern parts of the range, the Yellow Sea and Sea of Japan, where ice extent and seasonal persistence time have already been greatly reduced (Boveng et al. 2009). The threat may be mitigated somewhat in the Bering Sea, where a long-term range shift northward would be possible through Bering Strait to the Chukchi Sea, where seasonal formation of suitable ice is projected to occur beyond the current century under the most commonly used global climate models (Boveng et al. 2009). Disruption or alteration of the patterns of primary productivity and abundance of key prey species, either by sea ice loss or ocean acidification could also have detrimental effects on Spotted Seals, though the magnitude and even the direction of impacts are very uncertain (Boveng et al. 2009).

Conservation Actions [top]

Conservation Actions: In the United States the Spotted Seal is generally protected from all but subsistence hunting by Alaska Natives under the Marine Mammal Protection Act of 1972, which also generally prohibits import and export of parts or products from all marine mammals.

Commercial harvesting of Spotted Seals from vessels of the Russian Federation ended in 1994. Small scale commercial and subsistence harvests 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.).

Spotted Seals are listed in the Second Category (II) of the State Key Protected Wildlife List in China, listed as Vulnerable in the China Red Data Book of Endangered Animals, and designated a vulnerable species under the Wildlife Conservation Act of China (Wang 1998). However, as of 2004, no “conservation action, public awareness or education programmes have been carried out for the species in this region” (Won and Yoo 2004).

In 2000, Spotted Seals were afforded protected status under the Wildlife Conservation Act of South Korea. Despite this protection, the Liaodong Bay population, shared between China and Korea, has continued to decline (Han et al. 2010).

Classifications [top]

9. Marine Neritic -> 9.1. Marine Neritic - Pelagic
suitability:Suitable  major importance:Yes
10. Marine Oceanic -> 10.1. Marine Oceanic - Epipelagic (0-200m)
suitability:Suitable  major importance:Yes
12. Marine Intertidal -> 12.1. Marine Intertidal - Rocky Shoreline
suitability:Suitable  major importance:Yes
13. Marine Coastal/Supratidal -> 13.1. Marine Coastal/Supratidal - Sea Cliffs and Rocky Offshore Islands
suitability:Suitable  major importance:Yes
2. Land/water management -> 2.1. Site/area management

In-Place Research, Monitoring and Planning
  Action Recovery plan:No
  Systematic monitoring scheme:No
In-Place Land/Water Protection and Management
  Conservation sites identified:Unknown
In-Place Species Management
In-Place Education
1. Residential & commercial development -> 1.2. Commercial & industrial areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

11. Climate change & severe weather -> 11.1. Habitat shifting & alteration
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.2. Species disturbance
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.8. Other

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.1. Intentional use: (subsistence/small scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.2. Intentional use: (large scale) [harvest]
♦ timing:Past, Unlikely to Return    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale) [harvest]
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.1. Species mortality
  • 2. Species Stresses -> 2.2. Species disturbance

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.5. Persecution/control
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

9. Pollution -> 9.2. Industrial & military effluents -> 9.2.1. Oil spills
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.5. Threats
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends

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Citation: Boveng, P. 2016. Phoca largha. The IUCN Red List of Threatened Species 2016: e.T17023A45229806. . Downloaded on 18 January 2017.
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