A worker lays rails across the bed of a drained area of a lake used for the production of salt at the Sasyk-Sivash lake near the city of Yevpatoria in Crimea, October 5, 2014. The area has a long tradition of salt production, prepared from salt flats flooded with water from the Black Sea. (Photo by Pavel Rebrov/Reuters)

A swimmer disguised as Superman dives into the lake during the 78th “Coupe de Noel” (Christmas cup) swimming race in the Lake Geneva, on December 18, 2016 in Geneva. More than 1800 participants took part in the event, a 12-meter-long swimming off the Geneva's bank in the 7 degrees Celsius cold water. (Photo by Fabrice Coffrini/AFP Photo)

In this aerial view fishing boats are seen on the shore of the Lake Malawi at the Senga village on May 20, 2019 in Senga, Malawi. Hundreds of local traders gather each morning and afternoon at Senga, but fish populations are falling in Lake Malawi, Africa's third largest body of freshwater. (Photo by Gianluigi Guercia/AFP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Toure, a Gambian salt harvester, holds a basket filled with the salt collected from the crust of the bottom of the Lake Retba (Pink Lake) in Senegal on March 16, 2021. Lake Retba, divided from the Atlantic Ocean by a narrow corridor of dunes, owes its name to the pink waters caused by the Dunaliella salina algae and is known for its high salt content, up to 40% in some areas. (Photo by Marco Longari/AFP Photo)

An aerial view of a man standing on Lake Tuz, Turkiye's second largest lake, during sunset in Ankara, Turkiye on April 22, 2024. The lake, which is on the UNESCO World Heritage Tentative List with its unique natural structure, welcomes many local and foreign tourists every year as it provides 70 per cent of the country's salt needs. (Photo by Hakan Nural/Anadolu via Getty Images)

Fireworks explode over a floating Christmas tree in Lagoa Lake in Rio de Janeiro. (Photo by Victor R. Caivano/Associated Press)