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下载Iguana Alarm 鬣蜥预警
CHRIS WHEELOCK, CNN CORRESPONDENT
The fractured hull of the cargo ship Jessica is a constant reminder of the potential for catastrophe in the Galapagos Islands. She ran aground in January of 2001, spilling almost the entire cargo of diesel fuel and bunker oil. At first, scientists with the Charles Darwin Foundation, responsible for research and conservation of the Galapagos ecosystems, thought damage to the environment and its residents would be minimal. But researchers say further study revealed the dramatic loss of up to 15,000 marine iguanas. Particularly affected was the island of Santa Fe.
HOWARD SNELL, CHARLES DARWIN FOUNDATION
On Santa Fe Island, where the oil did reach, mortality rate went up to 72 percent, he says. This is the reason for the published paper in "Nature," reporting 72 percent mortality of the adult iguana population on Santa Fe Island was caused by the contamination of the oil spill by the Jessica boat.
Severe kill-offs of the iguanas in the Galapagos have been associated with the weather phenomenon known as El Nino in the past. And while iguanas have survived and recovered from natural events, scientists worry the added threat from a man-made catastrophe could be devastating. Results of the study published in "Nature" magazine suggests the iguanas died from subtle, long-term effects of the oil spill. The oil may have fouled their food supply, or been directly ingested. There are between 40,000 and 300,000 marine iguanas living on the 13 main islands in the Galapagos chain.
It is uncertain how the loss of the iguanas would affect the balance of the Galapagos' ecosystem, but scientists note they are the only sea-faring lizard in the world. They have no natural predators and remain herbivores. Marine iguanas are among the unusual creatures that evolved from land creature to sea- dweller, a change that helped form Charles Darwin's now famous theory.