A small barge spilled up to 2,000 gallons (9,000 litres) of diesel last week near Puerto Villamil, home to turtles, iguanas and sea lions, after strong currents thrust the fuel tank it was carrying overboard, officials said.

Park officials contained the spill about a mile from the port and applied chemical agents to help break up the diesel, which according to preliminary reports did not reach the shores of Puerto Villamil on Isabela island.

No animals were immediately affected by the spill, which environmental authorities admitted was small.

But independent experts said it was too soon to measure the its impact on microorganisms or marine species.

"We can't quantify the effects or tell which species are affected until we analyze marine species, fish, mollusks, crustaceans, to determine its real dimension," said Jaime Cevallos, a representative for the Charles Darwin research station.

HUNDREDS OF UNIQUE SPECIES

The Galapagos islands, 625 miles (1,000 km) west of Ecuador's coastline, are home to hundreds of unique species that each year lure thousands of foreign visitors.

The archipelago is still reeling from a January 2001 spill that dumped close to 240,000 gallons (one million litres) of fuel into its pristine ocean waters, and led ecologists around the world to question Ecuador's management of the islands.

The latest spill has heightened concerns that Ecuador doesn't have the resources to effectively manage the islands, after failing to implement a safer way to transport fuel to Galapagos electric plants after the 2001 spill.

"There are defects in fuel transport in all of Galapagos, in all the ports it is dangerous, and it is a process that makes events like this prone to occur," said Cecilia Falconi, coordinator for a Galapagos project at local environmental group Fundacion Natura.

The previous spill was mitigated as strong currents carried most of the fuel away from the islands, where it evaporated in the sun.

But a recent study showed 62 percent of the iguanas on Santa Fe island died within a year of the accident, stark evidence that even a low-level spill can cause serious damage.

"It's going to cause problems but it's hard to say how many. Most likely it will affect animals as it did previously with the marine iguanas," said independent biologist Eduardo Pichilingue.

Scientists said they hoped the diesel would quickly evaporate and thus be removed from harm's way, since it is a more volatile fuel than the bunker spilled last year by the "Jessica".

"The problem with the Jessica was the bunker, not the diesel," which mostly evaporated, Fernando Espinoza, director of the Charles Darwin station, told Reuters.