On one side are the rats, goats and other alien species that have made the islands their home, to the detriment of local flora and fauna and on the other, the hordes of eco-tourists descending on the equatorial paradise.
Last year around 126,000 people visited the Galapagos, and cruise ship companies have recently added the islands to their destinations. Felipe Cruz of the Charles Darwin Foundation, dedicated to conserving the islands, believes the Galapagos should not be used in this way.
"We don't want cruise ships in the Galapagos, we don't think it's sustainable," he says. The ships leave local people and the environment to deal with their laundry water and sewage waste. Second, the larger numbers of tourists visiting the same areas will disturb the wildlife. Third, the chances of bringing alien species or disease is greatly increased.
Cruise ships, however, are coming. The Ecuadorean government allows twelve 500-passenger cruise ships to visit the Galapagos a year. So far the only one has been the 698-berth MV Discovery, operated by Discovery World Cruises of Fort Lauderdale, Florida, which visited in May. Classic International Cruises, based in Lisbon, Portugal, has the Athena, which is scheduled to visit in 2008. Cruz says the ships bring their own food with them and don't deal with local people, so the tourist money doesn't filter into sustainable tourism.
Pirates used the islands as hideouts until the 19th century, introducing many non-natives such as rats, pigs and goats. Leonor Stjepic of the Galapagos Conservation Trust in London says the potential ecological impact of mass tourism poses a similar threat. "It is very difficult to perform adequate quarantine checks on a large ship with lots of people and luggage," she says. "West Nile virus has already been detected in Colombia. Imagine the devastation if that - or avian flu - came to the Galapagos."
When asked about the ecological risk to the islands, Classic International Cruises told New Scientist they will comply with the rules set by the Ecuadorean government and the Galapagos National Park Management as far as protecting the islands is concerned.
Stjepic insists that cruise ships are not a good thing for the islands. "It goes beyond environmental impact assessment. Even now we get invasive species, such as thrips, and blackberry, which has devastated the daisy trees in the highlands of Santa Cruz."
Managing the Galapagos is difficult, but there are successes. Most notably, Project Isabela, which eradicated thousands of goats that had devastated many of the islands in the archipelago.
Even large islands like Santiago and Isabela, each home to almost 100,000 of these alien invaders, are now goat-free. "The success of this project has acted like a catalyst, giving us confidence to take on other huge challenges in Galapagos," says Cruz.
Later this year the island of Pinta is to be the setting for one of the boldest. One hundred giant tortoises from nearby Española will be released onto Pinta's volcanic slopes. There is only one surviving Pinta tortoise, Lonesome George, and he was moved to the Charles Darwin Research Station on the island of Santa Cruz in 1972. His closest living relative - the Española tortoise - will act as a stand-in for him and his long-dead ancestors. "This is the first time that conservationists in the Galapagos have attempted to replace one species with another," says Cruz.
The tortoises should fill a hole in Pinta's ecological make-up. "In the absence of a dominant herbivore, the structure of the island's vegetation is changing," says Ole Hamann, a botanist at the University of Copenhagen in Denmark who has worked on Pinta since the 1970s. "Tortoises will open up the vegetation, making room for light-loving herbs and grasses."
Next for eradication are the non-native rats. In 2003, conservationists announced that around 200,000 Norwegian rats had been removed from Campbell Island, some 700 kilometres south of New Zealand. It was the most successful rat eradication scheme to date and the technique used, an aerial drop of poison specific to rats, is due to come to the Galapagos soon.
With cruise liners and mass tourism, however, enforcing adequate quarantine measures will be very difficult, says Stjepic. At the end of this month, there will be workshops to look at ways of capping the number of visitors to the islands. One obvious way is to put the price up, from the $100 entry fee currently charged, to $500.
From issue 2573 of New Scientist magazine, 12 October 2006, page 8-9
"Should leave nature alone...if one cannot care for it"