A marine iguana basks in the sun on Fernandina Island in the Galápagos. © Cherise Fong
Situated 1000 km off the coast of Ecuador, the Galápagos Islands evolved both geologically and biologically in isolation over several hundred millennia to become the famous prehistorical paradise. How has life been in the archipelago since the arrival of the human species?
Galápagos, special report (words and photos)
It was on Fernandina Island that I almost stepped on a marine iguana. It was stretched out on the ground, at the edge of the colony, immobile and camouflaged against the gray lava rocks. For a moment, I imagined the ironic fate of this legendary creature—the descendent of lizards emigrated from the mainland on a raft of vegetation, who adapted to the harsh conditions of this volcanic island by venturing into the sea to feed on algae, modifying and optimizing their anatomy over many generations and hundreds of thousands of years—only to be unceremoniously squashed by a tourist so overwhelmed by the surrounding landscape that she failed to see the treasure at her feet.
Fortunately, I stepped aside just in time. Unfazed, the prehistoric dragon didn’t bat an eyelid. It did snort out some salt, while continuing to bask in the equatorial sun. Here is the marine iguana’s home turf.
The Galápagos Islands are famous for their endemic animals, evolved without human contact, fearless or impassive: centenarian giant tortoises that inspired the name of the archipelago; blue-footed boobies and their clownish dance; soaring frigatebirds and their inflated red throats; statuesque iguanas; curious sea lions; playful penguins; bright red Sally Lightfoot crabs on black lava rocks; Darwin’s finches, whose multiple varieties of beaks are a perfect illustration of adaptive radiation, or the evolution of one species into several, as each new species adapts to survive in a changing environment.
Since Darwin’s time, the Galápagos archipelago has retained 95% of its endemic species—according to the Galapagos Conservancy, approximately 80% of land birds, 97% of reptiles and mammals, 30% of plants and 20% of marine species are found nowhere else in the world.
At the confluence of climate change
The exceptional biodiversity of the Galápagos, tied to its diverse microclimate, is due to its geographical location at the confluence of several marine currents: the warm Panama current from the north, the cold Humboldt current from the south and the deep, cold Cromwell current in the west, which bring nutrient-rich waters that feed ecosystems varying from coral reefs to penguins.
Periodically, the climatic and cyclical phenomenon of El Niño–La Niña warms the ocean and brings lots of rain. The warm waters dramatically reduce the marine supply of algae, phytoplankton and fish—on which marine iguanas, sea lions, penguins and flightless cormorants in particular depend—while the heavy rains disrupt coastal ecosystems where animals such as flamingos and sea turtles make their nests.
As a consequence of severe El Niño events in 1982 and 1997, scientists have observed that some bird species, including penguins and blue-footed boobies, lacking in nutrition from diminished resources, stopped breeding for several years in a row. Flamingos were unable to find enough food or nest in the lagoons. Marine iguanas went as far as to absorb their own bone mass, effectively shrinking their bodies and food requirements. Many dominant male iguanas and sea lions, already preoccupied with defending their respective territories, died of starvation during these periods. Recently, sea lions have been seen collectively herding giant yellowfin tuna. If some marine ecosystems have managed to recover from these shocks over time, it’s too early to know whether that will be the case for future cycles.
Climate warming exacerbates the already devasting effects of El Niño, while increasing the acidity of the oceans, which in turn leads to the bleaching of coral, a key species in most marine ecosystems.
Tui de Roy, renowned photographer and naturalist of the Galápagos Islands for the past 40 years, recalls the great coral heads that measured more than 4 meters across and were estimated to be over 500 years old: “They all died in ’82. They were in Santa Fe, right in the bay, giant coral heads. You had to be careful when you went in there with a boat, because you could actually hit them. Now even the dead remains aren’t there anymore. People have kind of forgotten about the fact that these things used to exist.”
John McCosker, researcher in aquatic biology at the California Academy of Sciences and specialized in the Galápagos Islands, remembers his expeditions from the late 1970s, where he and his colleagues would see in abundance a finger-sized species of damselfish. Since 1982, it hasn’t been seen again.
“This fish has certainly been around for hundreds and thousands of years, and now it’s gone,” McCosker regrets. “It’s a frightening sign of the future. Each of these species is affected by climate change—not always an extinction, but certainly a local extinction or an ecological extinction, where they can no longer perform their function within an ecosystem.”
Meanwhile, the scientist has returned from his latest visit to the Galápagos in January excited by his discovery of new marine species, in collaboration with Salomé Buglass, a young marine biologist from the Charles Darwin Foundation who is using a remotely operated vehicle to explore previously unknown ecosystems on seamounts.
But like many scientists, McCosker is not very optimistic about the fragile future of the Galápagos as the climate gets warmer: “If you were on the mainland of Ecuador, you could just move in a polar direction either north or south and find a habitat that’s cooler, and you could tolerate it. But you can’t in the Galápagos, there’s nowhere else you can go. Many species on land can just move to a higher altitude, but when you get to the top of the mountain and you can’t get any higher, you can’t do anything. You’ve run out of habitat opportunities… Life on Earth has to face climate change.”
Invasion of species
Since the first documented visit by Tomás de Berlanga in 1535, followed by three centuries as a temporary refuge for whalers, then the famous visit by Charles Darwin aboard the Beagle in 1835 and the stopover by Herman Melville that inspired The Encantadas in 1854, until the middle of the 20th century, the superficial landscape of the uninhabited islands of the Galápagos may have appeared unchanged.
But the animals who lived there would surely have reported otherwise. Ever since the first explorers set foot on the archipelago, men have brought in foreign species that quickly made themselves at home—goats, pigs and chickens, pet cats and dogs, ornamental plants and fruits, as well as rats, insects and other pathogens—with disastrous consequences. The livestock devoured vegetation without discrimination, released pets turned feral hunted birds and young reptiles, rats ate eggs out of nests, insects parasited native species…
Today, according to the Galapagos Conservation Trust, there are estimated to be some 1700 introduced and/or invasive species throughout the archipelago. Among the most destructive: goats (which specifically threatened the habitat of giant tortoises, finally eradicated on the islands of Pinta, Santiago and Isabela after 10 years in 2006); the fly Philornis downsi, which lays its eggs in the nests of land birds so that its larvae can feed on the chicks’ blood, eventually killing them; tropical fire ants; blackberry (Rubus niveus), which invades the humid zones; quinine (Cinchona pubescens), which eclipses native vegetation and transforms habitats in the highlands of Santa Cruz Island.
Among the most endangered endemic species: the mangrove finch, particularly vulnerable to Philornis downsi and painstakingly protected; the vermillion flycatcher (which I didn’t see at all during my 6 days on the islands); the Floreana mockingbird; Scalesia trees, first decimated by construction and agriculture then finished off by blackberries; and always, the iconic giant tortoises—one of the first species to arrive in the archipelago 2 or 3 million years ago—attacked by fire ants, feral dogs and other invasive species, and whose eggs and young are also vulnerable.
Already in the 18th and 19th centuries, buccaneers and whalers stocked up at each stopover in the Galápagos on dozens of giant tortoises—“delicious” creatures and later sources of oil, that could survive for months without food or water. It’s estimated that between 100,000 and 200,000 tortoises were taken from the islands during this period, leading to the extinction of 4 of the original 16 species—including Lonesome George, the last giant tortoise of Pinta Island, who died in June 2012 aged over a hundred years old, now preserved by taxidermy at the Charles Darwin Research Center. The current population of wild giant tortoises is estimated at around 20,000, in addition to those in the Tortoise Centers managed by the Galápagos National Park Directorate.
Plastic vectors
Seaside, an international team of scientists has identified 7 invasive species: two species of algae, a crab, a starfish and two other species that resemble ferns or moss. Often, these organisms have traveled long distances attached to the bottom of boats that arrive in the Galápagos Marine Reserve.
More recently, researchers have been examining big plastics (measuring more than 1 micrometer) picked up on the beaches to understand how they might serve as vectors to introduce new, potentially invasive, species to the reserve.
So far, according to Wilson Iñiguez, research assistant for the Marine Invasive Species project, the team has identified certain invertebrates such as gooseneck barnacles (Lepas anatifera) attached to pieces of plastic. “Not only are the plastics toxic to the animals that ingest them, they allow the attached organisms to travel much farther than they would normally,” he adds.
Throughout my week-long stay in the Galápagos spent walking on beaches and snorkeling in the sea, I admit that I didn’t see any garbage, but I know that a lot of it washes up on the less frequented beaches of the most inhabited islands, around Santa Cruz and San Cristóbal.
Like everyone, Wilson deplores the increasing presence of plastics in the environment, but he is optimistic about the possibility of eradicating plastics in the Galápagos, as well as the government’s repeated efforts to limit local pollution by prohibiting single-use plastics and even fireworks since the end of 2018.
“The main idea is to prove that it works,” says Wilson. “If it works here in the Galápagos, it can work in other parts of the world. It’s a slow process, but we’re working on it. Eventually, it’s just a matter of finding new ways of doing things.”
In parallel, marine life is still threatened by overfishing and illegal fishing, especially of sharks, poached for their fins, as well as sea cucumbers (another delicacy in China) and lobsters. The lobsters eat sea urchins, which eat coral; without lobsters, coral reefs suffer too.
Of course, the most invasive species of all is Homo sapiens.
Land tourism and Galápageños
In 1950, the Galápagos Islands had a population of 1349 inhabitants. By the 1970s, the archipelago was receiving more than 11,000 tourists a year, and its resident population had tripled. Today, the Galápagos is visited by over 240,000 tourists in a single year, with a population of 30,000 residents concentrated on 3% of the territory, where almost every one works directly or indirectly in the tourism industry.
While the Ecuadorian government has made several attempts to limit this human influx, it has not been very successful in controlling it. The development of land-based tourist infrastructure, in addition to the archipelago’s dependence on the mainland for materials, food and other provisions, introduces new risks of invasive species.
The Galápagos National Park was established in 1959, at the same time as the Charles Darwin Foundation, an independent and international nonprofit organization, to celebrate the centennial anniversary of the publication of On the Origin of Species. Covering 7970 km2, or 97% of the land surface of the Galápagos archipelago, the national park was declared a Unesco World Heritage Site in 1978. Managed by the Ecuadorian government, it defines strict rules of conduct for visitors, who must be accompanied at all times by a park-certified naturalist guide, in groups of no more than 16 people: no food on the islands, leave nothing behind, bring nothing back, no flash, and above all, never touch the animals.
In 2010, for the first time, the number of land tourists staying in hotels and eating in restaurants exceeded the number of tourists traveling on cruise ships (94,000 and 80,000 respectively). Since then, the number of land tourists has continued to increase, along with the development of tourism infrastructure.
While it may be more expensive to travel on a yacht, a few luxury cruise lines—Lindblad, Quasar, Ecoventura—are sustainably operated and actively support projects in collaboration with the Galápagos National Park, the Charles Darwin Foundation in Puerto Ayora and other local conservation and education initiatives.
And every ecotourist in the Galápagos, whether by land or by sea, returns home as an ambassador of this archipelago like no other in the Anthropocene age.
Bioblitz in Santa Cruz
José Guerrero, an Ecuadorian naturalist guide certified in 2008, reminds me that in the Galápagos, everything is connected: “If we don’t have the animals, we all have to go back to the mainland. The visitors will not come just for the beach. Tourism here is based on biodiversity. So the most important thing is to keep this biodiversity. We need to make sure that the animals are healthy and mating well, so that’s where science is important. But sometimes there are too many barriers between people who are doing the science, people who are making the decisions, people working in education, people working in tourism, the private sector, everyone pushing in a different way. We really need biologists to work with policy makers and people trying to talk among the different disciplines.”
In 1964, the Charles Darwin Research Station opened as the operational arm of the Charles Darwin Foundation in Puerto Ayora on Santa Cruz Island, the most populated site in the Galápagos. In addition to serving as a working base for international research scientists, it includes a library, an exhibition room, a café, and regularly hosts educational activities for children.
On January 24, 2019, during a team visit from the California Academy of Sciences (whose first expeditions to the Galápagos date back to 1905), the Charles Darwin Research Station organized the first Bioblitz in the Galápagos, on the island of Santa Cruz. For two hours, with iNaturalist on their smartphones, 16 curious and enthusiastic children and teenagers snapped photos of at least 79 identified species (finches, pelican, moss, snails, ladybug, cactus, tortoise, spiders, mushrooms, heron, flowers, butterfly, locust, wasps, turtle, stingray, lizards, fish, bivalves…). For some, it was their first visit to the Galápagos; for others, it was an occasion to rediscover their island from a new perspective.
For all of us, open-minded engagement from the youngest generation is, quite simply, hope. The Galápagos Islands may be our last opportunity to study a model microcosm of natural ecosystems, appreciate their ongoing evolution, and take action, both locally and at the level of international cooperation, on the way to collectively reclaiming life on Earth.
As Jonathan Franzen writes: “Only an appreciation of nature as a collection of specific threatened habitats, rather than as an abstract thing that is ‘dying,’ can avert the complete denaturing of the world.”
First, please do not step on the iguanas.
More information on the Galápagos National Park
Download the Atlas de Galápagos: Especies Nativas e Invasadores (in Spanish), 2018, published by the Charles Darwin Foundation