An Ecuadorian freighter ran aground off the Galapagos island of San Cristobal on Friday, but the Galapagos National Park Service says it doesn’t pose any threat “for the moment,” reports AFP.

The freighter is reportedly carrying 16,000 gallons of fuel, but officials say the “part of the vessel that is on the rocks is distant from the fuel tanks,” and does not pose a risk to the island chain’s unique habitat.

Workers are offloading the tanker’s cargo so that a high tide could possibly dislodge it. The park service also has drawn up an emergency response plan in case there is a spill.

San Cristobal is the easternmost and most populated island in the Galapagos chain. It was originally used as a penal colony for Ecuadorian criminals in the 1800s. Its land is most fertile of all the islands and around 6,000 people live there.

It was the first of the Galapagos chain that Charles Darwin landed on in the early 1800s. Darwin derived much of his theory of evolution observing the Galapagos' rich and extremely unusual plants and animals.

According to the Galapagos Conservancy, “around 80 percent of the land birds you will see, 97 percent of the reptiles and land mammals, and more than 30 percent of the plants are endemic. More than 20 percent of the marine species in Galapagos are found nowhere else on earth.”

In 2001 an Ecuadorian tanker spilled 175,000 gallons of diesel fuel when it ran aground near Shipwreck Bay. The New Scientist estimated that 62 percent of the marine iguana population on nearby Santa Fe Island died as a result of fuel brought there by currents. An Ecuadorian official said it was one of Galapagos’ “worst disasters.”