COHANA, Bolivia – Titicaca harbors legends that date back to the Incan empire but it is also home to a silent enemy, pollution, which in some places is bringing darkness and pestilence to the otherwise blue waters of the world’s largest high-altitude lake.
An overabundance of algae and black sludge forming on the lakebed has forced fish to migrate, threatening one of the major life sources for the populations dotted along its shores.
Considered sacred to the pre-Hispanic Andean cultures that inhabited its coasts for centuries, from the Tiahuanacu to the Inca, today Lake Titicaca is an essential spot on the Bolivian tourist trail, although its gentle waves offer an increasingly mucky welcome.
Titicaca, which in Quechua means “The Mount of the Puma,” is at a crossroads.
Efforts to preserve its iconic blue waters must be stepped up against the spread of green contamination, which threatens to eclipse the reflection of the snow-capped Andean peaks dancing on the surface.
Spread over 8,562 square kilometers, some 44 percent of the lake is situated on the Bolivian side of the border, the rest in Peru.
UNIQUE FROM A SCIENTIFIC POINT OF VIEW
Titicaca is one of the oldest lakes in the world and is important from “an archaeological as well as a geographic point of view,” Dario Acha, a biologist at the environmental department at the San Andres University of La Paz (UMSA), told Efe.
Acha highlighted the fact that Titicaca is the largest navigable high-altitude lake on Earth. It sits 3,809 meters above sea level and hosts species that have evolved to adapt to the unique ecosystem.
One example of this is the large Titicaca water frog, whose excess skin folds allow it to survive in water with low oxygen levels. The lake in the high Andes has 40 percent less oxygen than lower altitude lakes.
“If we add decomposition to this, which consumes oxygen, we will make it a very uninhabitable place for animals,” Acha said, in reference to particularly polluted areas in the bays of Cohana in Bolivia and Puno in Peru.
The Bolivian side of Titicaca is divided by the Tiquina Strait, which connects the upper lake in the northeast with the lower lake, known locally as Lake Pequeño for its smaller size, in the southeast.
The deepest point in the larger subbasin reaches 250 meters, while the smaller subbasin only reaches 40 meters, making it more susceptible to pollution as contaminating materials become more concentrated.
Titicaca and its basin, stretching from the River Desaguarero to Lake Poopo some 400 kilometers to the south, is fundamental for the ecosystem in the Bolivian highlands, where it contributes to humidity and thus soil fertility.
It is also an important temperature regulator for the Andean range and for population hubs like La Paz and El Alto, where roughly two of Bolivia’s 11 million inhabitants live.
THE TURBULENT WATERS OF COHANA
A man lying on his raft, floating alone on the water with the high sun above him, accompanied only by the crackling of his radio, this is now a common sight in the once busy fishing waters of Cohana Bay, in Lake Pequeño.
“All sorts of trash is coming into the water,” the villager said, noticing the presence of a reporter. He refused to give his name, claiming he was disenchanted by all the interviews he has given to students and journalists about the state of his local fishing spot to no avail.
He was referring to the River Katari, a tributary once so abundant in fish that three or four decades ago a fisherman could fill several barrels up with mauri or carachi, typical local catches.
But the Katari flows by residential areas of El Alto, the country’s second-largest city, and now brings with it diapers, plastic bottles and batteries, he said.
“It’s no longer possible to live off the lake,” Alfredo Machicado, another fisherman, told Efe. Having dedicated himself to the activity for the last 45 years, Machicado, a member of an association of 14 fishermen, down from 60 in its heyday, said that pollution had forced the fish away.
Machicado’s fishing grounds still boast clear waters but are on the cusp of becoming polluted. Due to his age, he has decided not to change area, despite the dwindling daily catch.
“The situation is bad. The plants, the totora reeds, the earth, the water are dirty, you can’t understand,” Max Catari, a boatman in his 80s who has dedicated his life to transporting visitors, told Efe.
During a trip, Catari pulls a contaminated green totora reed, a typical plant species on the lake, from the water to bring it to a local museum in a bid to show the effects of pollution.
He said that several years ago, there were as many frogs as stones in the lake, but that the pollution had caused them to die off. The local fish, on the other hand, can migrate given the lake’s sheer size, Catari said.
Parts of the water near Cohana Bay are infested by algae that grow on the surface. Totora reeds, which are used by locals as cattle fodder and to build rafts, are wilting, their roots turning yellow, rendering them useless for consumption for both humans and livestock.
THE POLLUTION PROCESS
One of the most recent cases of pollution in the lake occurred in 2015 when scientists noticed “uncontrolled plant growth,” Acha, who has been conducting studies in the area since 2012.
The phenomenon, which had a significant impact on the ecosystem in Cohana Bay, was attributed to increased levels of nitrogen and phosphorous detected in the water, a product of untreated human waste entering the lake.
This change in the water’s chemical content stimulated plant growth at a rapid speed. Algae grew across the surface of the bay, blocking light from subaquatic plants, and oxygen levels sank further still.
Acha said some studies had shown that frog populations in the affected areas had “been gravely impacted or had gone extinct.”
Pollution-related toxic gases in Titicaca also threaten the local birdlife, especially those that feed under the surface, such as gulls, flamingos and ducks.
“Bird mortality has been observed. We suspect that these deaths are down to increased levels of hydrogen sulfide (H2S) being released into the atmosphere,” he said.
It is this substance, commonly referred to as sewer gas, produces a kind of dark sludge at the bottom of the lake, from which neurotoxic gases emanate.
“It’s not an immediate process, it is something that has been going on for at least the last thirty years,” Acha said. “We are just beginning to see the consequences of this slow process of contamination.”
EFFORTS TO CURB CONTAMINATION
Bolivia and Peru opened a new stage in the programme to stop pollution in Titicaca during a binational cabinet meeting in 2016.
That same year, the Inter-American Development Bank (BID) approved a loan of $86 million to contribute to cleaning efforts on the Bolivian side of the lake and around the River Katari.
The financing was directed towards the treatment of wastewater and a bid to properly connect local households to the sewage system. It also helped with the disposal of solid waste in landfills in the Titicaca Basin.
Work to expand the Puchukollo wastewater treatment plant in El Alto began in 2018, the Bolivian Ministry of Environment and Water said.
However, there are latent contamination risks in large human settlements like Huarina, Achacachi, Escoma, Puerto Acosta and Copacabana, one of the biggest tourist attractions on the lake.
The director of the local environmental department in Copacabana, Emilio Chino, told Efe that the Bolivian towns near Lake Titicaca still did not have sewage treatment plants and that the process was still in its “bidding stage.”
However, the Peruvian and Bolivian regions surrounding the lake have formed a kind of commonwealth in their efforts to fight back against pollution.
With the help from the likes of France, which has provided $115 million, the Bolivian government had plans to stem the silent threat.
The Lake Titicaca-Katari Basin Sanitation Program has been working with local authorities since 2016 with plans to build 10 new sewage treatment plants in the area by 2022.
The Chiripa, Pucara and Tiahuanacota cultures admired the lake’s majesty. The Inca believed the Sun emerged from it.
Now, 2,000 years later, South America’s largest lake awaits a solution to preserve its natural and mythological legacy.