ISABELA ISLAND – A volcano in the Galapagos Islands has erupted for the first time in more than 30 years, spilling streams of molten lava and raising fears for the world’s only colony of pink iguanas.

The eruption has raised fears that the unique ecosystem that inspired Charles Darwin’s theory of evolution may be under threat.

On Monday, the Wolf volcano on Isabela Island erupted for the first time in 33 years, spewing fire, smoke and lava.

Experts say the ongoing eruption poses no risk to people living on the island.

The island holds the world’s only population of pink iguanas but authorities say that they are not in immediate danger.

The Galapagos National park said that the lava was flowing in a south-westerly direction.

The iguanas, “which share the habitat with yellow iguanas and giant Chelonoidis becki tortoises, are situated on the north-west flank, which raises hopes that they will not be affected,” the National Park said in a statement.

The fiery streams of lava that trickled down the volcano on Monday morning were on the opposite side, officials said.

The volcano lies on the northern tip of Isabela Island, the archipelago’s largest. It is 115km from Puerto Villamil, the only population centre on the island.

“The eruption generated a very large column of smoke that rose more than 10km into the air,” Sandro Vaca of Ecuador’s Geophysics Institute told the AFP news agency.

A tourist boat passing by the uninhabited area informed authorities the 1707-metre volcano was erupting.

Park officials then flew over the zone to assess the impact of the eruption.

Pictures released by the park show bright lava streaming down the volcano as a column of ash rises into the air and tongues of fire dart from the crater.

Vaca said the volcano’s activity could continue for several days, potentially causing further lava flows.

Park officials said the eruption posed no danger to tourists, and operations in the key tourism sector continued as normal in the area.

The Galapagos is a popular destination for tourists wanting to explore its unique ecosystem.

There are several varieties of iguanas on the islands.

Unesco has declared the Galapagos a World Heritage Site and has recently warned the ecosystem is in danger from increased tourism and the introduction of non-native species.

The variety of wildlife on the island famously inspired Charles Darwin to conceive the theory of evolution.

“One general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.” he wrote in On the Origin of Species after visiting the islands.

The Galapagos National Park Twitter account had earlier warned Isabela Island, where Wolf Volcano erupted, holds “the world’s only population” of the critically endangered Conolophus marthae, also known as the Galapagos rosy iguana.

But the park authority later said the iguanas’ habitat on the volcano’s north-west side appeared to be out of danger.

But environmentalists world wide are watching with concern for the pink iguanas, which were discovered in 1986 and established as a separate species after an analysis of their genetic makeup determined they were distinct from their cousins, the Galapagos land iguanas.

The iguanas are pink with charcoal stripes, and are listed as critically endangered by the International Union for Conservation of Nature.

The Galapagos chain of 13 islands and 17 islets, which sits about 1000km off the coast of Ecuador, is one of the most volcanically active regions in the world.