Japanese sea lion

Template:Short description Template:Pp-semi-indef Template:Speciesbox The Japanese sea lion (Zalophus japonicus) (Template:Langx, Template:Korean)<ref>Template:Cite web</ref> was an aquatic mammal that became extinct in the 1970s. It was considered to be a subspecies of the related California sea lion (Z. californianus) until 2003. They inhabited the western North Pacific and its marginal seas including the Sea of Okhotsk and the Sea of Japan, especially around the coastal areas of the Japanese Archipelago and the Korean Peninsula. They generally bred on sandy beaches which were open and flat, but sometimes in rocky areas. They were hunted commercially in the 1900s, leading to their extinction.

Taxonomy

8,000-year-old sea lion fossil

Prior to 2003, it was considered to be a subspecies of California sea lion as Zalophus californianus japonicus. However, it was subsequently reclassified as a separate species.<ref name="iucn status 12 November 2021" /> DNA analysis in 2007 estimated that the divergence point between the two sea lions took place around 2 million years ago (mya) in the early Pleistocene.<ref>Template:Cite journal</ref>

Several taxidermied specimens can be found in Japan<ref>Template:In lang "天王寺動物園で「絶滅の危機にある動物展」を開催します" Template:Webarchive Tennoji Zoo, Osaka, Japan.</ref> and in the National Museum of Natural History, Leiden, the Netherlands, bought by Philipp Franz von Siebold. The British Museum possesses a pelt and four skull specimens.<ref name=shimaneu>Template:Cite web</ref>

Description

Taxidermied specimen, Tennōji Zoo, Osaka, Japan

Male Japanese sea lions were dark grey, reaching lengths of Template:Convert and weighed about Template:Convert. Females were significantly smaller at Template:Convert long and weighed about Template:Convert with a lighter grey colour than the males.<ref name=JIBIS>Template:Cite web</ref>

Distribution and habitat

Japanese sea lions were found along the northwest Pacific coastline, specifically in Japan, Korea, southern Kamchatka Peninsula, and the Sakhalin Island.<ref>Template:Cite book</ref> However, they may not have existed in Kamchatka, with their northernmost range extending only to the Kuril Islands.<ref name="iucn status 12 November 2021" /> Sightings of individual Japanese sea lions still persist in Korea, but these are probably misidentified Steller's sea lions (Eumetopias jubatus).<ref>Template:Cite book</ref> The only reliable report from Kamchatka may have been of a single individual shot at Moneron Island in 1949.<ref name="iucn status 12 November 2021" />

Old Korean accounts also describe that the sea lion and spotted seal (Phoca largha) were found in a broad area containing the BoHai Sea, the Yellow Sea, and the Sea of Japan.<ref name=Itoo2001>Template:Cite journal</ref> Many places along the Japanese coastline are named after sea lions or seals, such as Ashika-iwa (海驢岩 or 海鹿岩, sea lion rock) , Ashika-jima (海獺島 or 海鹿島, sea lion island), and Cape Inubō (犬吠埼, dog-barking point). Bones of Z. japonicus dating to 3500–2000 BC were found in the Shell Mound in Dongsam-dong, Busan.<ref>Template:Cite journal</ref> Genetic evidence confirms the former presence of Z. japonicus on the Liancourt rocks.<ref>Template:Cite journal</ref>

Illustration of a Japanese sea lion in a swimming position

They usually resided on flat, open, and sandy beaches, but rarely in rocky areas. Their preference was to rest in caves.<ref>Template:In lang Zalophus californianus japonicus (EX) Template:Webarchive, Shimane Red Data Book 2004, Shimane Prefecture, Japan.</ref>

Exploitation and extinction

Sea lion (right) and fur seal, Wakan Sansai Zue (around 1712)

Sealing at Liancourt Rocks by Japanese fishermen in 1934

Many bones of the Japanese sea lion have been excavated from shell middens from the Jōmon period in Japan.<ref>The Jomon people in the northern Island Template:Webarchive, National Museum of Japanese History. </ref><ref>The Sannai Maruyama Site-Food Template:Webarchive, Aomori Prefecture, Japan, p. 7.</ref><ref>Template:In lang (en abstract available) Michiko Niimi, Sea Mammal Hunting of the Jomon Culture in Hokkaido, Bulletin of the Department of Archaeology, 9 (19901228), 137–171, University of Tokyo Template:ISSN</ref> An 18th-century encyclopedia, Wakan Sansai Zue, describes that the meat was not tasty and they were only used to render oil for oil lamps.<ref>Terajima Ryōan, Wakan Sansai Zue (ca. 1712), vol. 38, Amimals, p. 72, sea lion and fur seal[1] "其肉亦不甘美 唯熬油為燈油 (the meat is not tasty and just used to render oil for oil lamps.)".</ref> Valuable oil was extracted from the skin, its internal organs were used to make expensive medicine, and its whiskers and skin were used as pipe cleaners and leather goods, respectively. At the turn of the 20th century, they were captured for use in circuses.<ref name="iucn status 12 November 2021" />

Harvest records from Japanese commercial fishermen in the early 1900s show that as many as 3,200 sea lions were harvested at the turn of the century, and overhunting caused harvest numbers to fall drastically to 300 sea lions by 1915 and to a few dozen sea lions by the 1930s. Japanese commercial harvest of Japanese sea lions ended in the 1940s when the species became virtually extinct.<ref>Template:Cite news</ref> In total, Japanese trawlers harvested as many as 16,500 sea lions, enough to cause their extinction. Submarine warfare during World War II is also believed to have contributed to their habitat destruction.<ref name=kukmin070202>Template:Cite news</ref><ref name="korea times">Template:Cite news</ref> The last population survey dates from the 1950s and reported a population of only 50 to 60 animals on the Liancourt Rocks. The most recent sightings of Z. japonicus are from the 1970s, with the last confirmed record being a juvenile specimen captured in 1974 off the coast of Rebun Island, northern Hokkaido. There were a few unconfirmed sightings in 1983 and 1985.<ref name=JIBIS /><ref name=kukmin070202 /><ref name="encyclopedia of marine mammals">Template:Cite news</ref> In any case, it was one of the most recent marine mammal extinctions to occur, alongside the Caribbean monk seal which went extinct at around the same time.<ref>Template:Cite book</ref>

Attempted rewilding

Template:Update section In 2007, the South Korean Ministry of Environment announced that South Korea, North Korea, Russia, and China will collaborate on bringing back sea lions to the Sea of Japan, starting with a search for any Japanese sea lions that might still be alive.<ref>Zalophus japonicus. The Extinction Website</ref> The National Institute of Environmental Research of South Korea was commissioned to conduct feasibility research for this project.<ref>Template:In lang "독도 바다사자(강치) 복원에 대한 조사 및 타당성 검토요청 (Request for Research on Feasibility of Reintroducing Dokdo Sea Lions)"Template:Dead link, South Korean Ministry of Environment, 2006-01-09.Template:Dead link</ref> If the animal cannot be found, the South Korean government plans to relocate California sea lions from the United States.<ref name="korea times" /> The South Korean Ministry of Environment supports the effort because of the symbolism, national concern, the restoration of the ecological system, and possible ecotourism.<ref name=kukmin070202 />

Post-extinction claimed sightings or vagrant records

Sightings of single sea lions of unclear identities have been reported at Iwami, Tottori in July 2003,<ref>Template:Cite web</ref> and on Koshikijima Islands in March 2016.<ref>Template:Cite web</ref><ref>【動画】どこから来た？鹿児島近海でアシカ発見Template:Dead link</ref> Both animals were positively identified as Otariidae based on photographs, but their identities are unclear.

External links

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