Ecuador has asked the US for help in preventing an environmental disaster posed by a diesel fuel spill in the ecologically fragile Galapagos Islands.
The tanker Jessica, carrying 7,700 barrels of fuel, ran aground on Tuesday. It began leaking diesel oil on Friday into a bay on San Cristobal island.
The Galapagos archipelago, 600 miles west of the mainland, is the country's main tourist attraction, noted for its giant tortoises and uniquely evolved birds and plants.
Its plants and animals, found nowhere else in the world, have characteristics that helped Charles Darwin develop his theory of evolution.
In an interview on television Environment Minister Rodolfo Rendon, said: "We are asking for official help from the US Coast Guard, which has the specialised equipment for these types of operations.
"We have taken all the necessary measures that are available to us and we are taking measures to prevent any possible tragedy - and I would call it a tragedy - that might occur in the coming hours."
It is thought the ship ran aground due to a "navigational errer".
Galapagos National Park Director Eliecer Cruz described the situation as grave, saying: "The spill is threatening colonies of sea lions, marine iguanas, birds like the blue-footed boobies, sea gulls, masked boobies and sea life, including sharks and lobsters."