The Galapagos are, in a word, special. Created 3 million years ago by undersea volcanic eruptions, they are the newest members of a largely sunken archipelago that stretches 1,000 miles or so northeast to Central America. When the eastern islands began disappearing beneath the ocean millions of years ago, animals cut off from the mainland were forced to leapfrog westward from island to island. In isolation, they evolved into unique forms. Eighty percent of the 5,000 species of plants and animals that now live on the Galapagos are found nowhere else on Earth. Blue-footed boobies nest on its rocky shores. Giant tortoises amble over its hills. Even though the islands lie near the equator, penguins waddle on its beaches. One of two species of iguana on the islands dives into the ocean and eats seaweed, a diet it shares with no other reptile on Earth. An oil spill, even a small one, could wreak havoc on this diversity.
More than a jewel of diversity, the Galapagos archipelago is perhaps the most important place on Earth for understanding the history of life. “They’re kind of a sacred place to evolutionary biologists,” says Dolph Schluter of the University of British Columbia. In 1835 the HMS Beagle arrived at the islands on its voyage round the world, and the ship’s 26-year-old unofficial naturalist, Charles Darwin, collected some of its birds. Back in England, Darwin identified several new species of finches, each with a beak adapted to some particular diet–be it hard seeds or soft fruits. In trying to understand how the birds had acquired such a variety of beaks, Darwin hit upon natural selection, the cornerstone of his theory of evolution. Since then, scientists have returned to the islands to study evolution up close. They have observed, for instance, the minute, year-by-year changes in the beak size of these finches, documenting the mechanics of natural selection in unparalleled detail. “The Galapagos is a well-worked laboratory of evolution,” says Harvard University’s Edward O. Wilson.
Fortunately, on Jan. 23, the currents and winds shifted, pushing the spill northward and away from the rest of the archipelago. So far the oil-scrubbing rescue teams have had to treat only a few dozen boobies, sea lions and pelicans from San Cristobal and nearby Santa Fe Island. So will the Galapagos now revert to some pristine state? Hardly. For one thing, the spill may cause long-term damage that’s not yet visible. If it blocks the sun’s rays from reaching enough algae, the delicate marine food web could still collapse. “In another few months we’ll know how to classify [the accident],” says Peter Grant, a Princeton University biologist who has worked on the islands since 1973.
The wreck of the Jessica is also just a small part of an ongoing assault on the Galapagos wildlife that began back in 1532, when the Spanish explorers discovered the archipelago. Settlers soon brought with them Norway rats, cats, dogs, goats, pigs, burros and other alien species that hunted down the native animals, ate their eggs, competed with them for food–and drove their numbers down. Two species of birds that Darwin observed went extinct shortly afterward. Galapagos tortoises, which once roamed the islands in the hundreds of thousands, now number fewer than 15,000.
Pressure from the global economy has only made things worse. Fishermen strip the coral reefs of sharks, sea cucumbers, lobsters and other marine life to supply a fierce demand from Asia and the United States. As a result the Galapagos fishery may collapse in five years. Ecuadorans in search of work in fishing and tourism go to the islands by the thousands. The 50,000 tourists who go each year to the islands don’t help either, as the Jessica accident shows. Capt. Tarquino Arevalo, who ran the ship aground because he mistook a signal buoy for a lighthouse, was delivering fuel to one of the many tourist ships that dart between the islands. Carbon dioxide from the burning of fossil fuels also harms coral reefs by contributing to global warming and by acidifying sea water, which makes it harder for the calcium carbonate skeletons of millions of tiny sea creatures to form the reefs. In a few decades, the Galapagos coral reefs, among the most spectacular on the planet, may disappear.
The Galapagos may be special, but it is not the only ecosystem teetering on the edge. “The wreck of the Jessica and its filthy stain on the seas of Galapagos serve as a symbol of the dismal future that awaits us if we are careless with the remaining natural wonders of the world,” says Robert Bensted-Smith, the director of the Charles Darwin Research Station on the islands. In 1839, Darwin, in a calmer frame of mind, wrote: “The natural history of this archipelago is very remarkable. It seems to be a little world within itself.” His words remain true, but in a different sense: today this beleaguered little world is also a microcosm of the entire biosphere.
