Rising from the Pacific 600 miles west of Ecuador are arid islands whose name, for obvious reasons, is a Spanish word for tortoises. Indeed, the Galapagos islands are famous for tortoises weighing hundreds of pounds. What many people don't know, though, is that fascinating creatures also live in an undersea realm offshore.
Describing the contrast between the islands and their underwater bounty in a the 1924 book of, Galapagos: World's End, William Beebe wrote: "Host of sally-lightfoots [tidal crabs] were the most brilliant spots of color above the water in the islands, putting to shame the dull, drab hues of the terrestrial organisms and hinting at the glories of colorful animal life beneath the surface of the sea. "
Four currents converge in Galapagos waters: the Peru or Humboldt to from the south, the Equatorial from the West, the North Equatorial, and the Panama. Fish and invertebrates from different oceans and habitat ride these currents and quickly make themselves at home along the rocky shores, on a sandy sea bottom, and in the mangrove forests of the Galapagos.
Among the most playful creatures here are the sea lions. Slicing through the water at dazzling speed, they sometimes perform an underwater ballet of sorts, twisting, turning, stretching, and arching their sleek bodies amid clouds of plankton. A sea lion will swim just inches from a diver's mask as if approaching for a kiss, or it will nibble at a swim fin or embrace the diver with its flippers, all the while maintaining eye contact-a technique that requires incredible flexibility and agility.
A sea monster the size of a school bus also lives in Galapagos waters: the whale shark. Largest fish in the sea, it eats plankton and fish strained from the water by its wide mouth. Although encounters with it are rare here, encounters with other sharks are not. Six- to eight-foot-long hammerhead sharks, with heads shaped like sledgea hammers, swim in schools of a hundred or more. White-tip, Galapagos, and bull sharks, most larger than a man, are seen by nearly every explorer who enters these waters. Getting pictures of them while diving is difficult, though, because a diver's bubbles seem to frighten them.
Among the more unlikely denizens of equatorial waters are Galapagos Penguins. Only here and along the Pacific coast of South America do Penguins live near the Equator. They ply these waters with great ease, chasing fish and avoiding sharks. Out of water, they may be seen waddling about on the islands' volcanic rocks.
Another unique animal is the marine iguana, a ferret-size lizard whose distinctly reptilian features are adaptations for its life in the Galapagos: it uses its blunt snout to scrape algae from submerged rocks, it's clawed feet to grip slippery rocks, its muscular body and tail to swim in strong tides, and its spines to defend against predators.
Although the archipelago holds many wonders, it does not have a coral reef. Instead, diver's find dramatic volcanic rock formations beneath the sea. Some of them are bare; others are covered by red algae, orange and costing sponges, orange cup corals, and bushes of black coral.
One reason for the low number of reef-building corals is a weather phenomenon called El Nino. Periodically, El Nino brings an incursion of water that is poor in nutrients and unusually warm; these conditions are unfavorable for corals and plankton. El Nino also causes rainfall to increase, and large amounts of freshwater added to seawater are detrimental to coral growth.
Conversely, these seas hold a high number of fish-300 species, of which 17 percent are endemic. Among them are the hieroglyphic hawkfish, a bottom-dweller that seems to have symbols etched on its body, and the red-lipped batfish, with fashion-model-red lips. Not surprisingly, the archipelago attracts many fishermen.
Although the area is protected by an 1986 presidential decree making it the Marine Resource Reserve, it is still the site of illegal fishing. Park rangers simply don't have the resources to patrol almost 30,000 square miles. Luckily, the conservation effort is strong, being led in part by the owner of live-aboard dive vessels, Herbert Frei, Jr., who says that a plan is in the works to provide fisherman with a livelihood, while not significantly affecting the underwater habitat.
Efforts are also under way to save the islands' terrestrial animals, especially the tortoises. Because their shells come in different sizes and shapes-domed, saddle-back, or somewhere in between-these gentle giants formerly were thought to be members of several species. In fact, there is only one species, and it was almost wiped out by hunting and habitat destruction. Today, scientists at the Charles Darwin Research Station are working to protect and, in some cases, reintroduce the giant tortoises to more remote areas of the archipelago.
Fortunately some 750,000 birds still can be found among the islands. Flycatchers, mockingbirds, yellow warblers, hawks, owls, and finches are common. So far 19 species of seabirds, including the blue-footed booby, red-footed booby, frigate bird, and the waved albatross.
When naturalized Charles Darwin first came to the Galapagos in 1835, he noticed that animals of the same species looked different on different islands. Years later, he developed a revolutionary theory of evolution and wrote On the Origin of Species by Means of Natural Selection. What might he have thought if he had also seen the remarkable creatures in the sea surrounding islands?