| Spotted seal | |
|---|---|
 | |
| Spotted seal mother and pup in the Bering Sea | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Suborder: | Caniformia |
| Parvorder: | Pinnipedia |
| Family: | Phocidae |
| Genus: | Phoca |
| Species: | P. largha |
| Binomial name | |
| Phoca largha Pallas, 1811 | |
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| Spotted seal distribution | |
Thespotted seal (Phoca largha),[2] also known as thelarga seal orlargha seal, is a member of the familyPhocidae, and is considered a "true seal". It inhabitsice floes and waters of the northPacific Ocean and adjacent seas. It is primarily found along thecontinental shelf of theBeaufort,Chukchi,Bering andOkhotsk Seas[3] and south to the northernYellow Sea and it migrates south as far as northernHuanghai and the westernSea of Japan. It is also found inAlaska from the southeasternBristol 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.[4] It is sometimes mistaken for theharbor seal to which it is closely related and spotted seals and harbor seals often mingle together in areas where their habitats overlap.[5]
The reduction in arctic ice floes due toglobal warming led to concerns that the spotted seal was threatened withextinction. Studies were conducted on its population numbers, with the conclusion, as of 15 October 2009, that the spotted seal population in Alaskan waters is not currently to be listed as endangered byNOAA.[6]
The scientific name originated in the Greek word for seal,phoce, andlarga, the term used by theSiberianTungus people for this seal. The English common name comes from this seal's characteristic dark, irregularly shaped spots. AlaskanEskimo names includeissuriq (Central Alaskan Yup'ik language),gazigyaq inSt. Lawrence Island Yupik, andqasigiaqcode: ipk promoted to code: ik inInupiaq.[4]
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 82–109 kg (180–240 lb) and measuring 150–210 cm (59–83 in), roughly the same size as aharbor seal orribbon seal. The head of a spotted seal is round, with a narrow snout resembling that of a dog.[4]
The spotted seal has a relatively small body and shortflippers extending behind the body that providethrust, while the small flippers in front act asrudders. 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.[4][7]
Spotted seals are inhabitants of arctic or sub-arctic waters, often in the outer areas ofice floes during the breeding season. They tend not to live within densedrift ice. In the summer months they live in the open ocean or on nearby shores.[7]
Spotted seals are separated into three populations. TheBering Sea population includes approximately 100,000 in the westernBering Sea nearKamchatka, in theGulf of Anadyr inRussia, 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 theSea of Japan and theSea of Okhotsk. A third population of about 3,300 seals is to the south inLiaodong Bay, China andPeter the Great Bay, Russia.[7] There is also a smaller population of 300 spotted seals living in waters offBaekryeong Island located far north of the west coast ofSouth Korea.
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, if 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.[4]
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 100 cm (39 in) and 12 kg (26 lb).[8] Pups are weaned six weeks later. The maximum lifespan of the spotted seal is 35 years with few living beyond 25.[7][8]
Spotted seals dive to depths up to 300 m (980 ft) while feeding on a variety of ocean prey. Juveniles eat primarilykrill and smallcrustaceans while adults eat a variety of fish includingherring,Arctic cod,Pacific cod,pollock, andcapelin, as well asmollusks and crustaceans.[4][9] 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.[4]
Based on satellite tracking conducted onYellow Sea population, it was revealed that seals migrate more than 3,300 km (2,100 mi).[10]
On 28 March 2008, the U.S.National Oceanic and Atmospheric Administration (NOAA) initiated a status review[11] under theEndangered 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 15 October 2009 that two of the three spotted seal populations, together numbering 200,000 seals in or adjacent toAlaska, are not in danger of becoming extinct, nor are they likely to become so in the "foreseeable future",[6] 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."[12]
InChina, the spotted seal was under class-II national protection in the past,[citation needed] but the protection level was raised to class-I in 2021.[13] The main threats to the species in China are global warming, marine traffic, industry noise, ocean pollution, andpoaching for aquarium exhibition.[14]
InSouth Korea, spotted seals have been designated Natural Monument No. 331[15] and second-class endangered species.[16] An environmental activist groupGreen Korea United is currently working closely with local Chinese government to stop the seals from being poached by Chinese fishermen.[17]
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