Workers hold an 80 Kg Paiche (Arapaima gigas) to return it to a pool at a breeding farm in Nueva Loja, Ecuador, March 25, 2016. (Photo by Guillermo Granja/Reuters)

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)

A child looks at window cleaners work while dressed in sheep (C) and monkey costumes, denoting animal signs of the Chinese zodiac calendar, during an event marking the upcoming end of the year at a hotel in Tokyo, Japan, December 21, 2015. According to the zodiac calendar, 2015 is the year of the sheep and 2016 is the year of the monkey. (Photo by Thomas Peter/Reuters)

“Aurora Hunters”. Photographers taking part in a photography tour on the Lofoten Islands in Norway, pull over on the side of the road to take a photo of their first ever Aurora Borealis after spotting it from their tour bus. Photo location: Rystad, Lofoten Islands, Norway. (Photo and caption by Mark Gee/National Geographic Photo Contest)

A photo taken on August 29, 2014, shows Mount Tavurvur erupting in eastern Papua New Guinea, spewing rocks and ash into the air, forcing the evacuation of local communities and international flights to be re-routed. Mount Tavurvur, which destroyed the town of Rabaul when it erupted simultaneously with nearby Mount Vulcan in 1994, rumbled to life early in the morning on the tip of the remote island of New Britain. (Photo by Oliver Bluett/AFP Photo)

Liu Yang, China's first female astronaut, waves during a departure ceremony at Jiuquan Satellite Launch Center, on June 16, 2012. (Photo by Jason Lee/Reuters via The Atlantic)

Chacha, the male chimp, screams at a worker in Sendai, northern Japan, Thursday, April 14, 2016 after fleeing from a zoo. The chimpangzee tried desperately to avoid being captured by climbing an electric pole. Chacha was on the loose nearly two hours Thursday after it disappeared from the Yagiyama Zoological Park in Sendai, the city that's hosting finance ministers from the Group of Seven industrialized nations in May. (Photo by Kyodo News via AP Photo)

Street entertainer and fortune teller “Juana La Cubana” smiles holding a cigar in her mouth as she waits for tourists in Havana, Cuba, Sunday, May 24, 2015. Juana is 72 years old and has worked in the Cathedral square in Old Havana for 28 years. (Photo by Desmond Boylan/AP Photo)