Introduction to The Galapagos—Endangered Isles
A pair of strange-looking sea birds meet along a gravel pathway. The male begins to raise and lower his bright blue webbed feet. The female responds in a like manner. Every few seconds, the birds fold back and raise their wings and point their beaks skyward. The male emits a shrill whistle; the female, a guttural honk.
This is the courtship dance of the blue-footed booby, a famous resident of the Galapagos Archipelago, a group of islands that lie across the equator in the Pacific Ocean, 970 kilometers (600 miles) west of the coast of Ecuador. These isolated islands are home to giant tortoises and a host of other species found nowhere else in the world.
English naturalist Charles Darwin, who visited the Galapagos in 1835, called the islands a “living laboratory of evolution.” Today, the laboratory is in trouble. The archipelago has become a center of confrontation and international attention. The wildlife population shares the islands with a growing human population, and the result has been a conflict between wildlife and people.
The situation reached a boiling point on Sept. 1, 1995, when the president of Ecuador vetoed a measure that would have shifted administrative power over the Galapagos Islands from the federal government to local residents. The residents, eager for economic opportunities, wanted increased hotel construction in the islands and a freer hand in using the islands' natural resources. Although the president's veto pleased scientists, conservationists, and nature-tour operators, a small but vocal group of Galapagos residents were outraged. The next day, they retaliated by forcing one of the islands' two airports to close and by blockading the administrative offices of Galapagos National Park and the Charles Darwin Research Station. They also threatened to kill giant tortoises, take tourists hostage, and burn parts of the national park.
The economic goals of the growing number of Galapagos residents and international business ventures threaten the very existence of the islands' unique plants and animals. Scientists are greatly concerned and are trying to protect the islands while there is still time.
An Important Province
Politically, the Galapagos are 1 of 21 provinces that form the South American nation of Ecuador. Like each mainland province, the islands are headed by a governor appointed by the president of Ecuador.
Geographically, the Galapagos consist of 13 major islands varying in size from 14 square kilometers (5 square miles) to nearly 4,700 square kilometers (1,800 square miles), together with more than 100 smaller islands, islets, and rocks. About 97 percent of the land area of the Galapagos Islands and all of the waters surrounding the islands up to a 28-kilometer (17-mile) boundary have been set aside by the Ecuadorean government as a national park.
Scientifically, the Galapagos are of major importance because of their unique animals and plant life. One of the first people to study and observe the course of life in the Galapagos was Darwin. His 1835 stopoff at the islands was part of a round-the-world voyage aboard the H.M.S Beagle. What he saw during the five weeks he spent at the Galapagos was evidence that, in order to survive as species, animals and plants must adjust physically and behaviorally to changes in their environment. In each generation, he theorized, individual animals and plants possessing the most beneficial traits are the most likely to survive and produce offspring. In this way, certain traits become more widespread and species evolve into new species. This process, which Darwin called natural selection (and which is often referred to as "the survival of the fittest"), formed the basis for his theory of evolution. Darwin realized that natural selection is not evolution, but the mechanism that leads to evolution. Natural selection may take place within a generation, but evolution takes many generations to occur.
During his stay at the Galapagos, Darwin noted that the plants and animals vary from island to island and from the lowlands to the highlands of each island. Because of the islands' isolation for hundreds of thousands of years, many of their species are endemic—they exist only on the Galapagos and nowhere else on Earth. This is true of about 30 percent of the nearly 600 species of plants in the Galapagos. More than 80 percent of the land-based animals that inhabit the islands are endemic as well. Of the 57 species of birds, 50 percent are found only in the Galapagos. No amphibians live on the islands, and only two land mammals are native to the Galapagos—rice rats and bats. However, people have introduced a number of other mammals to the area over the years.
The Land and Wildlife of the Galapagos
Much of the Galapagos land area is covered with hardened lava, because the islands are volcanic in origin. The islands were formed by a dynamic process beneath the Earth's crust, its rocky outer “skin.” The crust is composed of about 20 tectonic plates, pieces of the continental and ocean floors that move at a slow but steady rate. The Nazca plate, on which the islands ride, passes over a hot spot, an intense source of heat deep within the Earth that melts the crust, giving birth to an underwater volcano. Through continuous lava flow and build-up, a volcanic island is born. As the Nazca plate continued to move, the hot spot created more volcanic islands, eventually forming the Galapagos chain.
The Galapagos Islands are relatively young. The oldest—Espanola and San Cristobal, to the southeast—are just 3 million to 5 million years old. The youngest island—Fernandina, in the northwest—is less than 700,000 years old. Volcanoes on Fernandina and Isabela still periodically pour out molten rock that cools and hardens.
Today, the islands are a favorite stop for so-called ecotourists. The blue-footed boobies charm the tourists and offer wonderful opportunities for close-up photographs. Like many Galapagos animals, the boobies seem fearless and make no effort to move out of the way. The nesting habits of these birds are quite casual, too—they lay and incubate their eggs on the ground, sometimes in the middle of visitor footpaths.
A Great Variety of Wildlife
Another famous resident that awes tourists and scientists alike is the Galapagos tortoise, for which the islands were named. (“Galapagos” is the Spanish word for saddle, which describes the shape of the tortoise's shell.) These huge reptiles—some weighing more than 225 kilograms (500 pounds)—have a long life span. Scientists estimate that they can live to be at least 150 years old. So a visitor in the 1990's could be looking at a tortoise that Darwin saw as a hatchling.
Many of the islands' beaches are dotted with sun-bathing sea lions. They, too, seem to ignore human visitors on shore. Snorkelers, however, often encounter these playful marine mammals swimming close by and even occasionally tugging on a swim fin. The islands' beaches are also home to prehistoric looking creatures called marine iguanas. These cold-blooded lizards, which use their surroundings to control their body temperature, grow to about 1 meter (3 feet) in length. Their dark-colored skin absorbs heat from the sun and from the sun-warmed lava on which they lie. Marine iguanas are the only lizards in the world that feed in the sea, and they are found only in the Galapa-gos. Land iguanas live on several islands as well. These are more colorful than the marine iguana—yellow and brownish-red.
The waters off-shore teem with colorful undersea life—parrot fish, angel fish, grunts, white tipped and hammerhead sharks, and moray eels. Dolphins can be spotted riding the bow-wave of ships that ferry visitors between islands. And in the northern and western waters, visitors may see sperm, minke, humpback, or killer whales. The fur seal, along with penguins, seems out of place on these equatorial islands.
There are also many species of Galapagos birds. Small bright-yellow warblers and vermilion flycatchers live inland; graceful red-billed tropic birds with long streaming tails haunt the island cliffs. Herons and flamingos populate the lagoons. Gulls, pelicans, penguins, doves, fin-ches, and the Galapagos hawk are part of the islands' bird life.
Inland Wildlife
Inland on the various islands are plants and animals that have adapted to the drought conditions that prevail much of the year. Plants include giant prickly pear and several other species of cactus, along with leafy plants such as the Galapagos tomato and the passion flower. The land iguana lives among the prickly pear cactuses and feeds on their pads, fruit, and spines. In an evolutionary response, the prickly pear cactuses, over a period of centuries, have grown taller and developed tougher bark to protect themselves.
The highlands are a world of their own. Because of the islands' peculiar weather patterns, there is enough moisture above 300 to 600 meters (1,000 to 2,000 feet) altitude for more lush vegetation. Here, many species of ferns grow, and tree trunks and shrubs, as well as the ground, are frequently covered with moss.
The Influence of Ocean Currents
The Galapagos Islands are very dry but not particularly hot because of the ocean currents and trade winds that bathe them. From July to December, a flow of ocean water called the Peru Current (also known as the Humboldt Current) streams north along the west coast of South America, bringing the cold waters of the Antarctic to the islands. The cold water cools the air above it, creating a temperature inversion layer, an area in which warm air rests on top of cold air. (The usual atmospheric situation, in any part of the world, is for air to be warmer at lower elevations and colder at higher elevations.) When evaporating water from the sea surface reaches the warm air of the inversion layer at the moisture level, it causes a continuous mist, called garua, that keeps the highlands lush and green. The lowland areas remain dry and cool.
From January to June, the winds that drive the Peru Current die down, and the warmer waters of the Panama Current bathe the islands. The inversion layer breaks up, rain falls on the coastal areas, and a more typical tropical climate prevails.
Sometimes, these climatic patterns are broken by an El Nino, a period of greatly altered weather conditions caused by changes in ocean currents. An El Nino occurs when no trade winds form to bring the Peru Current to the Galapagos. Then, the Panama Current warms the waters of the islands much longer, increasing the annual rainfall.
The additional rain benefits the islands' plants and the land animals that feed on them, but it is a danger for the sea birds and other animals that depend on the ocean for food. Fish feed on nutrients that come to them through upwelling, the rise of seawater from lower depths to the surface. This process diminishes when the surface waters warm. Fewer nutrients in the surface waters means fewer fish, and that in turn means less food for seabirds and marine mammals that feed on fish, such as fur seals and sea lions. Following a severe El Nino, large numbers of birds and mammals perish from starvation.
How the First Plants and Animals Reached the Galapagos
The abundance of life in the Galapagos has always been a puzzle to scientists, considering the remoteness of the islands and their unpredictable, and frequently extreme, climate. Biologists theorize that most of the species originated in and around South and Central America. Water creatures—fish, fur seals, sea lions, sea turtles, dolphins—would have been able to ride the ocean currents to the islands. Birds presumably arrived on the winds, as did the seeds and spores for the first plants. The reptiles, which have skins that can withstand salt water and the hot sun, and which can go for long periods without food and fresh water, probably rode in on some kind of vegetative raft. Amphibians and land mammals, being less sturdy than reptiles, could not have survived such a long journey. Thus, it is not surprising that there are no amphibians and just two native land mammals on the islands.
For the plant-eating land animals and land-birds to survive once they got there, plant life must have preceded them. Windborne bacteria, algae, and fungi may have been followed by lightweight seeds and spores. The first plants to flourish may have been lichens and mosses, and later ferns and grasses. The remains of these plants, along with weathered rocks, became the early soil of the Galapagos.
Survival In Harsh Surroundings
The first animal settlers probably did not find ideal living conditions on the islands, and most of them did not survive. They either arrived before their food supply was established or were wiped out during periods of severe weather. Survival into succeeding generations was equally chancy. A male and a female tortoise, for example, had to land on the same island and find each other for offspring to follow. For much of the life on the islands, it has been “survival of the lucky.”
This harsh environment was an ideal place for Darwin to study evolution in isolation. By the time the Beagle reached the Galapagos in 1835, near the end of a mapping expedition of South America and selected Pacific Islands, Darwin had become familiar with many South American plant and animal species. More than the similarities, it was the differences in related species on the Galapagos that puzzled him.
Darwin was particularly interested in the Galapagos finches. He noted thirteen distinct species on the four islands that he visited. The species varied in size, but otherwise were very much alike, with one notable exception—their beak structure. The size and shape of a bird's beak depends on what it eats. For example, finches with long pointed beaks feed on cactus flowers. Those with shorter but heavier beaks use them to break up seeds. Other shapes serve finches that dine on insect larva. Over time, the finches' beaks adapted to their food needs through the process of natural selection and evolution.
Since Darwin's time, many scientists have visited the Galapagos to study its wealth of plant and animal life and observe natural selection in action. One of the most exhaustive studies of Galapagos finches (which everyone now calls Darwin's finches) was made by biologists Peter and Rosemary Grant, of Princeton University in New Jersey, and their associates. Beginning in 1973, the British-born Grants followed more than 20 generations of the birds. By the mid-1990's, the research team had caught, measured, and leg-banded about 20,000 finches.
Through these long-range studies, the scientists observed the effects of extreme climatic changes on the birds. For example, in 1977, the normal wet season turned out to be a period of drought. By the end of the year, some 1,400 of one of the most common species of finches on the island of Daphne Major had been reduced to fewer than 300.
During the drought, the seed-eating birds ate all of the small, soft seeds that were available, until only larger, harder ones were left. The biggest finches with the largest, strongest beaks were the only ones able to crack open and eat those seeds. Consequently, more large finches than small ones survived the drought. In addition, many more males than females survived. The females who lost their mates, for the most part, chose males with larger bodies and larger beaks. So succeeding generations of finches were larger and had larger beaks. Rarely had such a dramatic change in a species been observed in so short a time.
The Impact of Human Activity
The plants and animals of the Galapagos have had to contend with the islands' unpredictable climate for tens of thousands of years. In more recent times, however, the greatest pressures on Galapagos species have come from human activity.
The first humans to make a significant impact on the islands were British buccaneers of the 1500's and 1600's. They stopped at the islands to recover from battles with the Spanish and to replenish their supplies of water and meat—the latter provided by the giant tortoises. During the 1800's, whalers and sealers from Great Britain and the United States hunted whales and fur seals in the seas off South America to near extinction. They also came close to wiping out the giant tortoises. Tortoises can go for months without food and water, so sailors would capture them, stack them upside-down in the holds of their ships, and enjoy fresh meat during their many months at sea.
The sailors also introduced many new species of animals and about 300 new plants to the islands—some deliberately, some by accident. The men released cattle, goats, and pigs on some islands before sailing away so that the animals could graze and fatten. On their return, the sailors would capture some of the animals and be assured of fresh meat while at sea. Cats, dogs, rats, and mice, which also began to populate the islands, may have escaped from ships and been marooned.
Competition Among Plant Species
Many of the introduced animal and plant species became competitors with, or even predators of, the native plants and animals, which had little or no defense against them. The goats—whose numbers at one time reached 100,000—eat the plants on which tortoises and land iguanas feed. The pigs trample the native plants and eat tortoise eggs and land and marine iguanas. Wild dogs eat iguanas, young fur seals, and penguins. An ornamental shrub called the lantana, brought to the Galapagos in 1938 for a family garden, spread so quickly that it has endangered the local lantana species by competing with it for the limited amount of available water. Even in the early 1990's, new species continued to be introduced to the islands. Native fishermen landing on uninhabited islands to process their catch often brought goats and other animals with them. And tourists traveling between the islands inadvertently carried seeds and insects with them.
More than nonnative species, however, it is people themselves that pose the greatest danger to the Galapagos. After Ecuador annexed the Galapagos in 1832, mainlanders began to colonize the islands. The early inhabitants fished, mined salt, collected moss to make dyes, and harvested giant tortoises for their oil. The human population stabilized at about 600 until the mid-1900's, when it more than doubled. A substantial increase in human population began again in the 1980's, fueled by the nature-tourism industry. By 1997, about 16,000 people were permanent residents of the islands, and the population was still growing.
Overpopulation A Concern
The four islands on which people live—Santa Cruz, Floreana, San Cristobal, and Isabela—are overpopulated. Municipal services, such as waste disposal and the provision of drinking water and electricity, are being pushed to the limit. Employment opportunities are also limited. Agriculture is marginal because of the poor soil on these volcanic islands, and fishing, long an important source of income, is threatened. Like the whales and fur seals in the 1800's, populations of fish and other edible sea creatures are now in peril. International fishing vessels, which are licensed to catch particular fish, such as tuna, also take great quantities of other species for which they are not licensed.
In addition, large international factory ships sail to the Galapagos area, where they purchase the catches of local fishermen. This source of cash encourages the islanders to fish illegally in coastal areas that were set aside as a marine reserve, and which are now part of the national park, and to exceed the quotas of fish they are allowed to catch. Sharks, in particular, are in danger of being depleted. High prices for shark fins, which are used in the making of some Oriental soups, have enticed fishermen to catch tens of thousands of sharks each year and cut off their fins.
Lobsters, crabs, shrimp, and other crustaceans are also in jeopardy, as are creatures called sea cucumbers. Sea cucumbers, which belong to a group of spiny-skinned sea animals called echinoderms, are prized in Asian countries as an aphrodisiac and a thickening and flavoring agent for soups. Though the government of Ecuador has prohibited the taking of any more sea cucumbers, Galapagos divers have continued to gather them, and in many areas of the islands the animal has all but disappeared.
Today, the largest source of revenue on the islands is the tourism industry. Providing services for tourists and tourist vessels accounts for more than half of the residents' income. For Ecuadoreans struggling to earn a living on the mainland, the impression that great amounts of foreign currency can easily be made in the islands lures more people to the Galapagos than the economy and land can handle.
Taking Steps to Protect the Islands
There are rules that all visitors to the Galapagos must adhere to: No one may disturb or remove anything from the islands, even a rock or sea shell; no one may touch or feed the animals; all visitors must stay on marked trails and be accompanied by trained tour guides; and tourists may visit only the 45 approved visitor sites. Nonetheless, about 60,000 people visited the Galapagos annually in the 1990's, and their collective presence adds to the strain on the islands' resources.
Beyond the regulation of tourism, many organizations, both national and international, are working together to try to solve the problems in the Galapagos. At the Charles Darwin Research Station (CDRS) on Santa Cruz Island, scientists are achieving some success with a hatchling-raising program for giant tortoises in an attempt to increase the numbers of this endangered species. The CDRS is the research arm of the Charles Darwin Foundation for the Galapagos Isles (CDF), an organization founded in 1959 by an international group of scientists who had become concerned about the destruction of Galapagos wildlife. The foundation operates under the auspices of the United Nations Educational, Scientific and Cultural Organization (UNESCO), the IUCN (the World Conservation Union)-a multinational conservation and wildlife management organization-and the government of Ecuador. The purpose of the CDF is to advise the government on conservation strategies for the islands and to operate the CDRS. Scientists at the CDRS gather data on the marine environment of the islands, study the effects of recently introduced plants and animals, and develop environmental education programs.
In 1968, Ecuador established the Galapagos National Park Service (GNPS) to implement the conservation goals set by the CDRS and to oversee Galapagos National Park. In 1986, the government established the Galapagos Marine Resources Reserve. The reserve consists of more than 70,000 square kilometers (27,000 square miles) of waters surrounding the islands, defined by a 28-kilometer (17-mile) boundary. In November 1996, Ecuador's National Institute for Forestry and National Parks declared the marine reserve a part of Galapagos National Park. No commercial fishing is allowed within the area, and traditional fishing is allowed only in certain parts of it. In addition, regulations govern the size and type of fish and sea creatures that may be taken, so that young and reproducing members of a species are left to ensure the long-term survival of the islands' sea life. Many conservationists in the mid-1990's contended, however, that the federal government failed to adequately patrol the marine reserve and enforce the regulations. Conservationists hoped that the national park service would be better able to enforce the existing regulations.
Galapagos Becomes A World Heritage Site
There has been other support for protecting the Galapagos as well. In 1978, the World Heritage Commission of UNESCO designated Galapagos National Park a World Heritage Site, recognizing the park as a unique area of natural importance. In December 1996, representatives of the World Heritage Commission expressed concern over the environmental problems of the park. The commissioners stated that, unless the government of Ecuador adopts effective measures to control the growing migration of settlers to the park, the introduction of new species to the islands, and the destruction of wildlife by fishermen, the islands will be placed on the World Heritage Sites in Danger List.
Important Steps For the Future
Johannah Barry, executive director of the CDF, agrees with the World Heritage Commission on the three most important issues facing the Ecuadorean government:
- The migration of people to the islands must be controlled. This may be a difficult policy to enforce because, like Americans who are free to move from state to state, Ecuadoreans expect to be able to relocate at will from province to province.
- The introduction of nonnative species must be stopped. Even if this is enforced, however, the extensive travel to the islands by ships and airplanes increases opportunities for insects, rodents, or other nonnative animals to come in as stowaways.
- Economic exploitation of the islands must be strictly controlled. The fishing industry is not the only problem. Trees, sand, gravel, and even lava are being removed from several islands for use in construction projects.
Environmental experts agree that solving the problems of the Galapagos will be costly. For example, the cash-strapped government of Ecuador needs funds to build or buy enough ships and aircraft to successfully patrol the islands. Many scientists and environmental activists believe that the financial burden should not be borne by Ecuador alone. They feel that a world concerned about the Galapagos' problems should be willing to share the costs of solving them. With international cooperation, they say, this world treasure can be preserved. And it should be—not just for its importance to science but also for the pleasure and wonder the islands provide to all who visit their shores.