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（本篇非嚴謹之專業翻譯但求不偏原意若有重大錯誤尚祈不吝更正）

本星期三（四月二十四日）一位海洋生物學家說海洋微生物藉由廢棄塑膠及人類製造的垃圾四處旅行，已侵入了南極以及熱帶島嶼並危害了當地物種。

成群的甲殼動物﹑軟體動物﹑蛀木蟲以及珊瑚搭著浮游的垃圾到達新的地方、危害當地物種及改變脆弱的生態系統。這些侵入嚴重侵害了如南極洲﹑賽席爾﹑馬達加斯加及其他有著地域性物種的地區<就是只有在當地才有的生物啦>。

一位參與一項研究（British Antarctic Survey）的海洋生物學家（David Barnes）說海中人類拋棄的垃圾比我們以前想像中的危險多了，海中廢棄物的問題必須得被重視。這些垃圾在副熱帶地區傳播兩倍外來物種，在高緯度地區傳播就不止三倍了。

海洋微生物比較傾向藉由人類丟棄的垃圾（如塑膠容器﹑打火機殼﹑牛奶箱）而不搭乘自然的東西旅行（如椰子或木頭）。因為人類丟的垃圾太多以致於微生物很容易就附著在上面散播到幾乎是全世界各地去。Barnes說在熱帶地區有幾乎一半的垃圾會被這些生物附著。

南極最大的威脅

接近地極處的海平面人類廢棄物的量達到了有五倍之多。尤其是若是全球暖化削弱了原本南極對外來生物入侵的屏障之後<冰～極低溫>，入侵的海洋微生物可能會無法挽回的改變南極洲的生態系統。

Barnes說如果冰冷的海水溫度是南極洲對外來微生物最大的屏障的話，極地暖化會減低這層限制。屆時到處都會有相同層級的物種了。

科學期刊"Nature"中報導Barnes的發現是根據在全球三十個孤立的島嶼經過了十年對人類拋棄物對沿岸洗刷的研究而得知。其中塑膠製品佔了多數，他是"堅固"的垃圾，也比其他材料的垃圾更容易被為微生物所附著。

Barnes說當新的物種到達了像Galapagos的地方，他們很有可能會取代當地所特有的物種。一旦一地的特有種被取代了，他們也就永遠地消失了。

Barnes正在擴大他的研究，尋找可以在其他島嶼進行沿岸垃圾調查的人，這些島嶼包括了 the Andamans, L'Ile Amsterdam, Bermuda, Chagos, Clipperton, Cocos/Christmas, Gilbert, Midway, Society, Socotra, Trinidad, 及 Wake. Barnes的email是dkab@bas.ac.uk.

禁止從船上丟棄廢棄物的法規雖然已經開始發生作用，但是Barnes說我們還需要做的還有很多因為要是一旦有其他地區的微生物入侵，要將他們移除已經是不可能的事情了。

Marine organisms ride plastic, threaten ecosystems

Thursday, April 25, 2002

By Patricia Reaney, Reuters

LONDON — Marine organisms traveling on flotillas of discarded plastic and other human-made rubbish are invading Antarctica and tropical islands and threatening native species, a marine biologist said Wednesday.

Armies of barnacles, mollusks, sea worms, and corals are hitching rides on floating debris and moving into new areas where they can endanger native species and drastically change fragile ecosystems. Antarctica, the Seychelles, Madagascar, and areas which have the most endemic species are most at risk from the invaders.

"Rubbish at sea is much more dangerous than we had previously assumed. The problem of dumping at sea has got to be addressed," said David Barnes, a marine biologist at the British Antarctic Survey. The debris has doubled the spread of alien species in the subtropics and more than tripled it at high latitudes.

Marine organisms prefer to travel on discarded plastic containers, cigarette lighters, and milk crates than on natural matter such as coconuts or logs. Because the human-made garbage is so abundant it is easy for the organisms to hop on and travel to virtually anywhere in the world. "In the tropics you have up to 50 percent of debris being colonized," said Barnes.

GREATEST THREAT TO ANTARCTICA

Closer to the poles, humans have quintupled the amount of material floating on the ocean surface. Invading marine species could irrevocably change ecosystems in Antarctica, particularly if global warming weakens the natural seawater barrier that keeps out alien species.

"If freezing seawater temperature is the main barrier to alien organism invasion of Antarctica, polar warming could lessen this constraint," said Barnes. "Nowhere has the same levels of species which occur there and nowhere else."

Barnes' findings, which are reported in the science journal Nature, are based on a 10-year study of human litter washed ashore on 30 remote islands around the globe. Plastic dominates the rubbish in most places. It is the most durable type of litter and is more readily colonized by organisms than other materials.

"When a new species arrives in a place like Galapagos, it has the potential to displace the native species which are there and only there," Barnes said. "Once they are displaced from an environment which is the only place they occur, they are gone forever."

Barnes is expanding his research and is looking for people who can conduct shore debris surveys on other islands, including the Andamans, L'Ile Amsterdam, Bermuda, Chagos, Clipperton, Cocos/Christmas, Gilbert, Midway, Society, Socotra, Trinidad, and Wake. He can be contacted by email at dkab@bas.ac.uk.

Regulations forbidding the dumping of waste from ships has begun to make a difference, but Barnes said more needs to be done because once an invading organism gets into an area, it is impossible to remove it.

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