Isaac Callizaya (pictured below), 39, grew up with the sound of waves lapping on the shores of Lake Titicaca, a giant body of water on the border between Bolivia and Peru that at 3,800 meters (12,500 ft) above sea level is the highest navigable lake in the world.
Left: A member of Professor Lazzaro's research team takes samples during a field trip in Cohana bay. Right: Algae floats in shallow water in Cohana bay.
Over time, a buildup of sediments, toxic blooms and climate change could cause the Lago Menor to become shallower and eventually dry up, he says.
"This catastrophic scenario is not science fiction. Of course it will take decades, centuries to happen," he says, while driving through the high-altitude mountains overlooking the lake. "It will be faster if no action is taken."
Left: Limachi gathers totora plant to use in art and crafts project to be sold at Pariti island museum. Right: Limachi makes a small boat of totora plant for sale.
Oscar Limachi, 48, a member of the local Qewaya community who works as a tour guide on the lake, says that waste from El Alto and a lack of understanding about pollution risk changing the habitat forever.
"It is also our fault, people throw garbage and plastic everywhere, they don't understand this is polluting," he says, adding that many plant varieties in the lake had already vanished.
"Fish used to live, eat and lay their eggs amongst these plants. Now there are no plants, so no fish," he says. "We are afraid that someday the fish will disappear or migrate forever."
Manuel Seoane was a 2018 Reuters photojournalism grant winner. Click on the names to see the stories by the other grantees, Ekaterina Anchevskaya, Nicky Woo, Loren Elliott and Thomas Nicolon.
Photo editing by Gabrielle Fonseca Johnson, Writing by Adam Jourdan, Editing by Rosalba O'Brien