人為因素 造成加勒比僧海豹滅絕 | 環境資訊中心

人為因素 造成加勒比僧海豹滅絕

2008年06月12日
摘譯自2008年6月9日ENS美國華府報導;陳維婷編譯;蔡麗伶審校

Henry W. Elliott手繪加勒比海僧海豹,由國家博物館典藏。圖片來源:ENS經過5年的調查,美國聯邦政府科學家證實「加勒比僧海豹」(Caribbean Monk Seal)已完全滅絕。這種海豹又被稱為西印度僧海豹,是加勒比海與墨西哥灣一帶唯一的亞熱帶海豹,也是第一種由人為因素導致滅絕的海豹。

加勒比僧海豹過去散佈在加勒比海、墨西哥灣與西大西洋,南至美國佛羅里達南端,北到喬治亞與南卡羅來納州的海岸都有加勒比僧海豹出沒的紀錄。

當加勒比僧海豹在岸上休息、生產、照顧後代的時候,獵人輕鬆就可手到擒來,美國海洋與大氣總署(NOAA)的生物學家表示,人類狂捕濫殺才造成加勒比僧海豹滅亡。世人最後一次確切見到這種海豹,是1952年在牙買家與墨西哥尤卡坦半島之間的小塞拉納島( Seranilla Bank)。

1967年,加勒比僧海豹被列入美國當時的瀕危物種名單,並於1979年納入瀕危物種法案保護,此後研究人員曾深入調查幾個尚未證實的回報紀錄,但最後都發現是其他種類的海豹。

科學家無法確定加勒比僧海豹真正滅絕的時間,雖然1952年之後就再也沒有明確的紀錄,但海豹的壽命約有2、30年,專家相信60、70年代左右也許還有僧海豹存活。

NOAA漁業部的生物學家貝克(Kyle Baker)呼籲,「世界上還有另外兩種僧海豹,族群都正在減少,希望加勒比僧海豹的滅絕能讓我們學到教訓,加強對他們的保護。」與加勒比僧海豹同屬的夏威夷與地中海僧海豹都處於瀕危、可能絕種的狀態,現存的夏威夷僧海豹不到1200隻,地中海僧海豹則僅有500隻。

夏威夷僧海豹目前受到NOAA漁業部的保護,其族群每年減少4%,生物學家預估未來3、4年總數可能少於1千隻,成為世界上最瀕危的海洋生物之一。夏威夷僧海豹面臨許多威脅,包括幼海豹缺乏食物、被海洋廢棄物纏繞、遭鯊魚捕食,還有休憩、育幼的海灘受侵蝕消失等。

其他幾種在近代滅絕的海洋哺乳動物包括18到19世紀左右消失的大西洋灰鯨,以及18世紀末期可能因捕鯨業者濫捕而絕種的大海牛(Steller’s sea cow)。NOAA專家表示,加勒比僧海豹也是在同一時期開始遭到大量獵殺。

Caribbean Monk Seal Declared Extinct
WASHINGTON, DC, June 9, 2008 (ENS)

After a five year review, federal government scientists have determined that the Caribbean monk seal has gone extinct. Also known as the West Indian monk seal, this was the only subtropical seal native to the Caribbean Sea and Gulf of Mexico and is the first type of seal to go extinct from human causes.

Once widespread throughout the Caribbean Sea, Gulf of Mexico, and west Atlantic Ocean, these seals were found in the United States from the Florida Keys and along the coast north to the states of Georgia and South Carolina.

Monk seals became easy targets for hunters while resting, birthing, or nursing their pups on the beach. Overhunting by humans led to these seals' demise, according to biologists with the National Oceanic and Atmospheric Administration, NOAA. The last confirmed sighting of the seal was in 1952 in the Caribbean Sea at Seranilla Bank, between Jamaica and the Yucatan Peninsula.

Caribbean monk seals were listed as endangered on March 11, 1967, under the Endangered Species Preservation Act, and relisted under the Endangered Species Act on April 10, 1979. Since then, several efforts have been made to investigate unconfirmed reports of the species. These expeditions only confirmed sightings of other seal types.

Scientists are unsure about exactly when Caribbean monk seals went extinct. Although there have been no confirmed sightings since 1952, the seals lived 20 to 30 years, so experts believe that some adults possibly lived into the 1960s or 1970s.

"Worldwide, populations of the two remaining monk seal species are declining," said Kyle Baker, biologist for NOAA's Fisheries Service. "We hope we've learned from the extinction of Caribbean monk seals, and can provide stronger protection for their Hawaiian and Mediterranean relatives." Hawaiian and Mediterranean monk seals are endangered and at risk of extinction. There are now fewer than 1,200 Hawaiian monk seals and fewer than 500 Mediterranean monk seals.

NOAA's Fisheries Service is responsible for protecting the Hawaiian monk seal. That population is declining at a rate of about four percent per year, and NOAA biologists predict the population could fall below 1,000 animals in the next three to four years, placing the Hawaiian monk seal among the world's most endangered marine species. Hawaiian monk seals face survival challenges such as lack of food sources for young seals, entanglement in marine debris, predation by sharks, and loss of haul-out and pupping beaches due to erosion.

Other species of marine mammals that have gone extinct in modern times include the Atlantic gray whale, which disappeared sometime in the 1700s or 1800s, and stellar sea cow which became extinct in the late 1700s, presumably due to overhunting by whalers. Exploitation of Caribbean monk seals began during the same time period, the NOAA scientists say.

全文及圖片詳見:ENS

作者

蔡麗伶(LiLing Barricman)

In my healing journey and learning to attain the breath awareness, I become aware of the reality that all the creatures of the world are breathing the same breath. Take action, here and now. From my physical being to the every corner of this out of balance's planet.