The Secret Garden

The crystalline rivers of the Serra da Bodoquena offer a window into Brazil’s freshwater biodiversity. But with deforestation on the rise, that window is becoming cloudier.

The snake was 7 meters (22 feet) long, her body as thick as a truck tire. She was curled beneath the overhanging bank of a river in central Brazil, submerged in water so clear it might have been an aquarium. And she was less than 50 centimeters (20 inches) from photographer Luciano Candisani’s lens.

But this green anaconda (Eunectes murinus), known in Brazil as a sucuri, showed no interest in Candisani or the two guides who had led him to her watery lair. She had more deadly business to attend to: killing the smaller snake she had just mated with. Because female anacondas fast throughout their seven-month pregnancy, they need one last meal as their eggs are fertilized, says Jesus Rivas, an anaconda expert from New Mexico Highlands University. Sometimes, that means squeezing to death and then eating one of their suitors.

Rivas had seen anacondas eating their own kind several times before, in Venezuela and Bolivia. But because the snakes usually live in turbid swamps, he wasn’t able to capture it on film, nor did he know if it was widespread. Candisani’s photo of the Brazilian giantess strangling her mate provides valuable evidence that the behavior is “really part of the ecology of anacondas,” Rivas says. “I have never seen a picture as beautiful as that one.”

Such beauty—and scientific insight—is only possible because of the astounding water quality in the Serra da Bodoquena, a swell of mountains and plateaus in the Brazilian state of Mato Grosso do Sul. Water that filters through the porous limestone of the Bodoquena emerges with such purity that the rivers seem to glow. At the same time, the water erodes the limestone, creating a wonderland of waterfalls, caves, and turquoise pools that offer habitat for giant river otters, tapirs, caimans, snakes, subterranean cave worms, enormous varieties of fish, and so many colorful aquatic plants that Candisani calls the region an “underwater garden.”

“One-fifth of the world’s fresh water is in Brazil,” he says. “But most rivers have murky water that obscures the beautiful life inside. The Bodoquena is different… This place is like a window to the unknown.”

For two decades, Candisani has returned again and again to the Bodoquena, entranced by what he finds in its crystalline rivers. But in recent years, he’s noticed a worrying trend: The water is getting murkier. Rivers where the visibility once seemed limitless are now sometimes clouded with silt, and his window into the unknown is growing more opaque. Locals who run the region’s ecotourism industry are also concerned, as are scientists and conservationists. But saving the rivers of the Serra da Bodoquena is daunting, because their greatest threats arise not in the mountains themselves, but in Brazil’s broader political and environmental landscapes.

The crystal clear waters of the Bodoquena serve as both home and hunting ground to anacondas, otters, and myriad other creatures.

The Serra da Bodoquena rises like an island from a forested savanna known as the Cerrado, which covers nearly a quarter of Brazil. The Cerrado is sometimes called the “upside-down forest” because up to 70 percent of its biomass lies underground, in roots that sink deep into the earth to reach the subterranean aquifer that nourishes plants during the long dry season. Some of South America’s largest rivers are born here, but few people outside the region have heard of it.

“For many years, people focused on the conservation of the Amazon,” says Edgardo Latrubesse, a geologist with Singapore’s Nanyang Technological University. “Nobody was caring about the Cerrado. Nobody was paying attention. So that was a good opportunity to expand the agricultural frontier there.”

From an agricultural perspective, farming the Cerrado makes sense: the rich aquifer and sunny climate conspire to make it prime real estate for growing things. But from an environmental view, that productivity has been devastating. Between 2000 and 2014, native vegetation in the Cerrado was destroyed at a rate 2.5 times greater than in the neighboring Amazon rainforest. More than half of the Cerrado ecosystem is now gone, replaced mostly by cattle ranches and industrial monocultures of soybeans. Under the administration of President Jair Bolsonaro, deforestation is only accelerating.

Bolsonaro campaigned in 2018 on a platform to expand agriculture, one of the few sectors of the Brazilian economy that stayed stable during the financial and political shakeups preceding Bolsonaro’s rise. In his short time in office, the conservative president has already made good on his promises, slashing environmental enforcement, approving the use of hundreds of new pesticides—24 of which are banned in Europe—and emboldening large landowners to push deeper into virgin forests. The human-caused fires now scorching Brazil to make room for more ranches and cropland are likely one consequence of Bolsonaro’s influence.

Yet while the burning Amazon has garnered the world’s attention, the Cerrado may ultimately suffer more. Only 8 percent of the region is formally protected, compared to nearly 50 percent of the Amazon, and some 30 percent of the fires currently ripping across Brazil are burning in the Cerrado.

Even the Serra da Bodoquena—long considered too mountainous and remote to be profitable for agriculture—hasn’t been spared. Luiza Coelho, whose family runs the ecotourism business Grupo Rio da Prata, explains that newly-plowed fields and plodding cattle in the broader Cerrado region sometimes send eroded soil and fertilizers rushing through the river valleys of the Bodoquena. And in December 2018, a new farm in the Serra da Bodoquena itself clearcut land right up to a river that runs through the Coelho’s property. The farmer openly flouted a law that Luiza’s father helped pass, which requires a 150-meter (500-foot) buffer of vegetation on each side of rivers in the Serra da Bodoquena region. Without this buffer, a heavy rain temporarily turned one of the Bodoquena’s gin-clear rivers an alarming shade of orange, and the river continues to run muddy when it rains.

One way that locals like the Coelhos are trying to save their rivers is through tourism, which has more than doubled in the Bodoquena region over the past two decades. While tourism gets a bad rap in some places for damaging sensitive environments and stressing wildlife, the industry here may help protect wildlife by giving people a financial incentive to leave the forest intact.

That’s because only a fraction of the Bodoquena—the 76,890-hectare (190,000-acre) Parque Nacional da Serra da Bodoquena—is protected by the government. Most land is privately owned: All of Luciano Candisani’s photos were taken on private land, and the hundreds of thousands of people who come here each year to snorkel in caves, float down rivers and rappel down waterfalls do so mostly on private land. While private ownership leaves landowners free to graze cattle or cut trees with little oversight, it also gives them the option to make money by charging tourists to visit their properties. Given the Instagrammable allure of azure waterfalls and translucent pools, many have concluded they can make a better living from the latter.

The Coelho family, for instance, has turned 560 hectares (1,400 acres) into a Private Reserve of Natural Heritage, a designation that gives them tax breaks in exchange for keeping the land free of development. They and other landowners have also placed science-based limits on the number of tourists who can visit the rivers each day, created a conservation nonprofit funded by a hotel tax, and taken law-breaking farmers to court. “We are really committed to this unique place in the world,” says Luiza Coelho. “We want to see it safe.” 

While Bodoquena residents have little control over what happens in the broader Cerrado region, their efforts are helping to ensure that the forest in their own mountainous corner of it, at least, stays intact. After the river through the Coelho’s property, near the town of Bonito, ran orange earlier this year, some tour operators were horrified that the area’s reputation for pristine water had been spoiled. But Luiza Coelho says that the episode woke Brazil up to the growing threats faced by the Bodoquena, prompting state politicians to form an emergency committee to address river health and develop a project that uses drones to monitor water quality. “People were thinking that Bonito is lost forever,” she says. “But it is not lost. I think the future is going to be brighter.”

Conservationists are betting that ecotourism will help to preserve the pristine waters of the Bodoquena by providing an alternative to farming and mining.

Although tourists are increasingly drawn to the water of the Serra da Bodoquena, scientists have only begun to document the region’s biodiversity. When entomologist Paulo Ricardo Barbaroza de Souza surveyed butterflies in the Bodoquena between 2009 and 2015, he found 20 species not previously known to exist in the area, including three that were new to science. Similar surveys by other scientists uncovered a new species of cave worm, two new species of fish, and amphibians and snakes that live nowhere else on Earth.

Luciano Candisani, too, continues to ply the rivers of the Bodoquena to illuminate the activities of animals whose lives unfold beneath the surface of Brazil’s prolific freshwater. During one trip, his guides told him about a place where tapirs (Tapirus terrestris) regularly crossed from one side of a river to the other. Over the next two weeks, Candisani spent nearly 100 hours there, hovering at the water’s edge with a mask and snorkel in hopes of catching a tapir swimming across the river. When one finally splashed into the water, he was astounded to see it walking underwater instead of swimming, trotting over the riverbed as if it were dry land.

But without good baseline data on the Bodoquena’s biodiversity, it’s hard to know how tapirs and other species are being impacted by the agricultural fervor tearing across Brazil. Muddy rivers can clog the gills of fish that are adapted to clearer water, while other animals may be more affected by what happens on land. Anacondas, for instance, aren’t bothered by murky water, but because water quality reflects the habitat as a whole, it may indicate that the peccaries, capybaras and other animals that anacondas prey on have lost their homes, which could eventually jeopardize the anacondas as well.

For now, though, the visions that Candisani has captured during his forays into the Bodoquena’s secret gardens are still out there: a giant river otter (Pteronura brasiliensis) arching through a turquoise channel, its webbed paws splayed open like fins. A yacare caiman (Caiman yacare) lying in wait on a river bottom, watching for prey with menacing eyes. Candisani hopes that by offering a glimpse into these animals’ hidden underwater lives, he’ll inspire more people to preserve the Serra da Bodoquena’s unique ecosystem. “Each time you go to the Bodoquena, it’s a different story,” Candisani says. “And it’s a story that I will keep telling.”

Luciano Candisani

Luciano Candisani began his career as a photographer of scientific expeditions while he was still a graduate student at São Paulo University. In his work, he strives to capture the world's vast wilderness areas and images that reveal the link between species and their environments. Candisani is a contributing photographer for National Geographic and is the author of seven photographic books, several exhibitions, workshops, and stories featured in a variety of publications.

Krista Langlois

Krista Langlois is a freelance journalist and essayist based in Durango, Colorado. In addition to her work as a contributing editor for bioGraphic, she writes about people and nature for publications including Adventure Journal, The Atlantic, Hakai, National Geographic News, Outside, and Smithsonian. Find more at or on Twitter @cestmoilanglois.

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