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(单词翻译:双击或拖选)
Forensic1 Testing of Ivory Could Combat Elephant Poaching
The sweeping2 grasslands3 of the African savannah might not exist without elephants. They knock down so many trees that forests transform into plains, where other grazers and birds feed. Elephants maintain the shape of the land, and without them, everything would change. And for many, that would make the world a poorer place.
“There’s some connection between humans and elephants that would be a really sad thing to lose,” says Kevin Uno of Lamont-Doherty Earth Observatory4 at Columbia University.
Uno warns that elephant extinction5 is a possibility this century, as poaching of African elephants is at an all-time high. There are only about 400,000 left in the wild, and 30,000 are killed each year for their tusks7. “In a span of 15 to 20 years, we could lose our elephants,” the researcher said.
Elephant ivory is highly sought-after as a carving8 material, especially in China and Japan. Trade in ivory was made illegal in 1989 under the Convention on International Trade in Endangered Species (CITES). Ivory that was harvested before the ban, however, is still legal to buy and sell. This is a perplexing issue for anti-poaching efforts: how to tell the old, legal ivory from the new, illegal ivory?
An international team of scientists, including Dr. Uno, determined9 that the answer can be found with a test measuring the level of radioactive carbon in a piece of ivory.
Atmospheric10 radiocarbon has been at an especially high level since nuclear weapons testing by the United States and Soviet11 Union in the 1950s. The radioactive element has been degrading ever since. By matching the amount of radiocarbon in a tusk6 with the amount in the atmosphere at a given time, the researchers can tell when the tusk grew - and when the elephant was killed.
The team's findings were published in the Proceedings12 of the National Academy of Sciences. The researchers say they hope the test will allow investigators13 to distinguish legally-sold ivory from before the trade ban, from illegal ivory that was poached more recently. This will presumably enable more effective enforcement of the ban on ivory trading, and disruption of poaching.
The technique can also be used to date horns and tusks from other animals, including rhinoceroses14, which are at even worse risk of extinction due to poaching.
Kevin Uno says that enforcing the trade ban is only part of the battle to save elephants. The ivory trade is completely driven by the demand for ivory, and he advocates efforts to educate buyers about the consequences of their actions.
“What we need to send,” said Uno, “is a very clear message that when you buy something that’s made of ivory, there’s an elephant that died for that.”
The Obama administration has announced an executive order to combat the illegal sale of endangered animals in Africa. The order provides $10 million to benefit anti-poaching efforts throughout sub-Saharan Africa.
1 forensic | |
adj.法庭的,雄辩的 | |
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2 sweeping | |
adj.范围广大的,一扫无遗的 | |
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3 grasslands | |
n.草原,牧场( grassland的名词复数 ) | |
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4 observatory | |
n.天文台,气象台,瞭望台,观测台 | |
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5 extinction | |
n.熄灭,消亡,消灭,灭绝,绝种 | |
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6 tusk | |
n.獠牙,长牙,象牙 | |
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7 tusks | |
n.(象等动物的)长牙( tusk的名词复数 );獠牙;尖形物;尖头 | |
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8 carving | |
n.雕刻品,雕花 | |
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9 determined | |
adj.坚定的;有决心的 | |
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10 atmospheric | |
adj.大气的,空气的;大气层的;大气所引起的 | |
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11 Soviet | |
adj.苏联的,苏维埃的;n.苏维埃 | |
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12 proceedings | |
n.进程,过程,议程;诉讼(程序);公报 | |
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13 investigators | |
n.调查者,审查者( investigator的名词复数 ) | |
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14 rhinoceroses | |
n.钱,钞票( rhino的名词复数 );犀牛(=rhinoceros);犀牛( rhinoceros的名词复数 );脸皮和犀牛皮一样厚 | |
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