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)

Olive Ridley turtle hatchlings (Lepidochelys olivacea) sit in baskets and trays at the turtle camp La Gloria, before their release into the ocean in Tomatlan November 15, 2013. Twenty years ago, Mexico's government implemented ecological plans to protect the sea turtles from being hunted for their leather and meat and established conservation areas and a pay system for local residents to protect turtle nests. Millions of baby turtles hatch on the shores in November and December, according to an environmental group. It is estimated that in 2012, there were 20 million newborns. Hatching season is still underway, but officials say they expect there will be even more turtles born this year. (Photo by Alejandro Acosta/Reuters)

“The Red River Hog (Potamochoerus porcus), also known as the Bush Pig (but not to be confused with P. larvatus, common name “Bushpig”), is a wild member of the pig family living in Africa, with most of its distribution in the Guinean and Congolian forests. It is rarely seen away from rainforests, and generally prefers areas near rivers or swamps.

Red River Hogs eat grass, berries, roots, insects, molluscs, small vertebrates and carrion. They are capable of causing damage to plantations. Red River Hogs typically live in herds of 6-20 members led by a dominant boar. Sows rear 3-6 piglets at a time.”

Photo: Two 17 day old red river hoglet twins forage for food next to their mother Bahiti at London Zoo on August 23, 2007 in London, England. Red River hoglets inhabit the forests and swamps of West and Central Africa. The recent additions to the London Zoo pig pen have been eagerly awaited by zoo keepers. (Photo by Chris Jackson/Getty Images)

Negin Ekhpulwak, leader of the Zohra orchestra, an ensemble of 35 women, practises on a piano at Afghanistan's National Institute of Music, in Kabul, Afghanistan April 9, 2016. Playing instruments was banned under Taliban rule in Afghanistan, and even today, many conservative Muslims frown on most forms of music. Living in an orphanage in the capital, Kabul, 19-year-old Negin Ikhpolwak leads an ensemble of 35 women that plays both Western and Afghan musical instruments. In a country notorious internationally for harsh restrictions on women in most areas of life, Negin's story highlights a double challenge. (Photo by Ahmad Masood/Reuters)

Indonesian child jockey Egi, 8, poses for photographs as he participates in a traditional horse race marking Indonesia's 70th independence anniversary, in Bima, West Nusa Tenggara province, Indonesia, 08 August 2015. Horse racing is the traditional sport in the area and a cultural heritage which continues to be preserved by the people of Bima, a small city on the east side of Sumbawa island. Similar races also held in Sumbawa Besar regency and Dompu regency. (Photo by Mast Irham/EPA)

An Olympic Airways airplane stands on the premises of the former Athens International airport, Hellenikon June 16, 2014. For about six decades Hellenikon was Athens' only airport but it closed down in 2001 to make way for a newer, more modern airport before the city hosted the 2004 Olympic Games. After languishing for years as a wasteland of crumbling terminals, Hellenikon is set for resurrection as a glitzy coastal resort. Lamda Development, controlled by Greece's powerful Latsis family and leading a consortium of Chinese and Abu-Dhabi based companies, has big dreams for the area since signing a 915 million euro deal for a 99-year lease in March 2014. (Photo by Yorgos Karahalis/Reuters)

Devotees bow to a passingTibetan Buddhist monk on his way to take part in a special prayer during Monlam or the Great Prayer rituals on March 5, 2015 at the Labrang Monastery, Xiahe County, Amdo, Tibetan Autonomous Prefecture, Gansu Province, China. Labrang Monastery is one of the six great monasteries of the Gelug school of Tibetan Buddhism and one of the largest outside of the Tibetan Autonomous Region. Monlam, the most important prayer event for many Tibetans was banned during the Cultural Revolution in China but once again in recent years it is celebrated in many areas. (Photo by Kevin Frayer/Getty Images)

In this Monday, September 22, 2014 photo provided by the Utah Division of Wildlife Resources, a young cougar is released back into Utah's mountains by the Utah Division of Wildlife Resources in an undisclosed site in central Utah. State wildlife officials received reports of the cougar roaming Sunday afternoon in a residential area of the city's eastern flank, a few miles from the base of the Wasatch Mountains. Authorities say cougars generally avoid humans but sometimes enter neighborhoods close to their mountain habitats. (Photo by Steve Gray/AP Photo/Utah Division of Wildlife Resources)