Misplaced Pages

Revision as of 21:51, 22 September 2007

The Japanese Sea Lion (Zalophus japonicus or Zalophus californianus japonicus) is thought to have become extinct in the 1950s.

It was listed before 2003 as a subspieces of California Sea Lion (Zalophus californianus ssp. japonicus) and raised to species level. Many taxonomists do not consider the Japanese Sea Lion a separate species but rather a subspecies of the California Sea Lion while some argued that japonicus, californianus, and wollenbaeki (Galápagos Sea Lion) as distinct species because of their distant habitation areas and behavioral differences.

They were found in the Sea of Japan (East Sea), especially around the Liancourt Rocks and Ulleungdo, and the coastal areas of the Japanese Archipelago and the Korean Peninsula. They bred on flat, open and sandy beaches and sometimes in rocky areas.

Currently, several stuffed specimens can be found in Japan and the National Museum of Natural History, Leiden, the Netherlands brought by Philipp Franz von Siebold. The British Museum is holding a pelt and 4 skull specimens.

Physical description

Male Japanese Sea Lions were said that they were dark gray and got up to 450 to 560 kg and 2.3 to 2.5 meters long that were larger than male California Sea Lions, while females are significantly smaller at 1.64 meters long and lighter in color than the males.

Range and habitat

The Japanese Sea Lions were used to be found in the Sea of Japan, especially around the Liancourt Rocks, where was the last breeding ground, and Ulleungdo where was sometimes called as sea lion (or seal) island (gajido, 可支島, 가지도), the Oki islands to southern Sakhalin. The coastal areas of the Japanese Archipelago from the south west (southern limit of the Sea of Japan side: Nagasaki, southern limit of the Pacific Ocean side: Miyazaki), to Hokkaidō, the Kuril islands, and southern tip of the Kamchatka Peninsula, and the Korean Peninsula up to Tumen River. Korean old accounts also describe that the sea lion and Spotted Seal (Phoca largha) were found in broad area containing the Bo Hai, the Yellow Sea, and Sea of Japan. The sea lions and seals left a lot of relavant place names all over the coast line of Japan including Inubosaki point (犬吠崎, lit. dog-barking point) because of the similarity of their howls.

They bred on flat, open and sandy beaches and sometimes in rocky areas. They preferably rested in caves.

Food and foraging

Fish, shellfish, squid, and octopus.

Lifestyle and reproduction

They bred on flat, open and sandy beaches and sometimes in rocky areas. They preferably rested in caves.

Human utilization

The Japanese Sea Lion was captured for use in circuses and killed to produce commercial products. Valuable oil was extracted from the skin, its internal organs were used to make expensive oriental medicine, and its whiskers were used as pipe cleaners. Sometimes they were eaten but not preferably.

Extinction

The Japanese Sea Lion was common in the past around the coast of the Japanese Archipelago, but declined rapidly after 1930's from overhunting and increased competition with commercial fisheries.

Liancourt Rocks

Harvest records by Japanese commercial fishermen in the early 1900s show that as many as 3,200 sea lions were harvested at the turn of the century. In 1903, Nakai Yōzaburō, a Japanese businessman, built a fishery house on the uninhabited Liancourt Rocks to aid in harvesting them and subsequently, until the outbreak of World War II in 1941, the hunting of sea lions in this location was subject to government approval. A former fisherman of Oki Islands told that they worked to protect the sea lion population to ensure perpetuity of the resource before WWII. Harvest numbers fell drastically to 300 sea lions by 1915 and to a few dozen lions by the 1930's. Commercial harvest of sea lions ended in 1940's likely leading to their eventual extinction. In total, Japanese trawlers harvested as many as 16,500 sea lions. The last confirmed reports of the sea lions came decades later by Korean coast guards in the 1950's, although other unconfirmed sightings on the Liancourt Rocks continued into the 1970s. It is possible these were, however, escaped Z. californianus seals. The last confirmed record of a Z. japonicus in Japan was a juvenile, captured in 1974 off the coast of Rebun Island, northern Hokkaido.

Population Revival Efforts

Despite their likely extinction, in 2007 a joint research venture between North Korea, South Korea, Russia, and China will search for any surviving sea lions in Chinese or Russian waters and return them to their traditional breeding ground.

References

1. ^ "2007 IUCN Red List (EX) Zalophus japonicus". World Conservation Union. Retrieved 2007-09-21. "There have been no documented reports of Z. japonicus since the late 1950s. The last credible report was 50 to 60 individuals on Takeshima in 1951 (Rice 1998). Individual sightings reported as recently as 1974 and 1975, cannot be confirmed as confusion with escaped Z. californianus cannot be ruled out."
2. ^ Template:Ja icon Zalophus californianus japonicus (CR), Red Data Book, Japan Integrated Biodiversity Information System, Ministry of the Environment (Japan). "The Japanese sea lion (Zalophus californianus japonicus) was common in the past around the coast of the Japanese Archipelago, but declined rapidly after 1930's from overhunting and increased competition with commercial fisheries. The last record in Japan was a juvenile, captured in 1974 at off the coast of Rebun Island, northern Hokkaido."
3. ^ Template:Ja icon "ニホンアシカ剥製標本", the ReCCLE (Research Center for Coastal Lagoon Environments) Museum, Shimane University, Japan.
4. ^ Template:Ja icon (en abstract available) Itoo Tetsuro, Fujita Akiyoshi, Kubo Kin-ya, "Pinniped records on the neighbouring waters of the Korean Peninsula: Japanese sea lions and larga seals recorded in the ancient literature of Korea", 野生生物保護 (Wildlife conservation Japan),Vol.6, No.2 (20010731), 51-66, Wildlife Conservation Society ISSN 13418777.
5. Template:Ja icon "天王寺動物園で「絶滅の危機にある動物展」を開催します", Tennoji Zoo, Osaka, Japan.
6. "Lies, Half-truths, & Dokdo Video, Maps 2 Supplement", Occidentalism, January 13th, 2007.
7. Template:Ja icon Zalophus californianus japonicus (EX), Shimane Red Data Book 2004, Shimane Prefecture, Japan.
8. Template:Ja icon Zalophus californianus japonicus (EX), Shimane Red Data Book 2004, Shimane Prefecture, Japan.
9. "Incorporation of Takeshima into Shimane Prefecture", Ministry of Foreign Affairs (Japan).
10. Template:Ja icon "李ライン翌年竹島にニホンアシカ多数生息", The San-in Chuo Shimpo, 2007/05/10. "研究の一環として聞き取り調査した杉原顧問は「戦前、隠岐の漁民は計画性を持ってニホンアシカを捕獲していた。韓国側は日本の乱獲が絶滅の原因というが、証言を聞く限り、乱獲したのはむしろ韓国の方だ」と韓国側の主張に反論した。"
11. Template:Ko icon"일본어부에 의해 멸종당한 독도 강치". Dokdocenter.org. 2007-03-05. Retrieved 2007-09-20.
12. ^ Template:Ko icon "독도에 바다사자 복원한다". The Kukmin Daily. 2006-02-02. Retrieved 2007-09-21. a) "푸른울릉·독도가꾸기모임 이예균 회장은 "일본 자료를 살펴보면 독도는 단순히 바다사자가 살던 섬이 아니라 바다사자의 최대 번식지였다"며 "일본의 다케시마어렵회사가 1905년부터 8년 동안 독도에서 1만4천여마리나 집중 포획하면서 바다사자가 멸종의 길로 접어들었다"고 말했다.", b) "50년대 독도의용수비대가 활약할 당시만 해도 20∼30마리씩 떼를 지어 독도 연안에서 서식하는장면이 목격됐다. 독도의용수비대원이던 이규현씨(82·울릉군 울릉읍 도동리)는 "당시 독도에서 강치(바다사자) 무리를 간간이 볼 수 있었고, 울릉도 주민들은 이를 가재, 강치로 부르기도 했다"고 말했다."
13. ^ "Extinct Sea Lions to Bring Back to Korea". Korea Times. 2007-09-05. Retrieved 2007-09-06.

• Extinct carnivores
• Mammals of Japan
• Pinnipeds