Empty water containers hang outside a mud house of a park ranger at Cejar lagoon at Atacama salt flat near San Pedro de Atacama, Chile, August 15, 2018. REUTERS/Ivan Alvarado SEARCH "MINE LITHIUM" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A jockey competes past horses that lost their riders on mud flats during the tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Competitors race on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Jockeys ride horses on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Jockeys ride horses on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Competitors race on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Competitors race on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Competitors race on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Competitors race on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

A jockey rides her horse on mud flats during the tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Jockeys ride horses on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Jockeys ride horses on mud flats during their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

Jockeys ride horses on mud flats before their tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

A guide (L) leads a group of people along the mud flats at low tide around the Mont Saint-Michel 11th century abbey off France's Normandy coast March 21, 2015. At the Mont Saint-Michel, where some of the biggest tides in the world occur, visitors gathered to watch the tide disappear out of sight, exposing areas of beach and rock visible only every 18 years. REUTERS/Pascal Rossignol

A group of people walk on the mud flats at low tide around the Mont Saint-Michel 11th century abbey off France's Normandy coast March 21, 2015. At the Mont Saint-Michel, where some of the biggest tides in the world occur, visitors gathered to watch the tide disappear out of sight, exposing areas of beach and rock visible only every 18 years. REUTERS/Pascal Rossignol

ATTENTION EDITORS FRENCH LAW REQUIRES THAT THE FACES OF MINORS ARE MASKED IN PUBLICATIONS WITHIN FRANCE 

Mud flats sit where water used to be next to the Great Salt Lake Marina west of Salt Lake City, Utah, August 4, 2014. The Drought forced an early end to the sailing season for some Utah enthusiasts on Monday as a huge crane lifted boats out of the Great Salt Lake State Park Marina, where officials say the water is at its lowest level for more than 50 years. Picture taken August 4, 2014. REUTERS/George Frey (UNITED STATES - Tags: ENVIRONMENT) 

Mud flats sit where water used to be next to the Great Salt Lake Marina west of Salt Lake City, Utah, August 4, 2014. The Drought forced an early end to the sailing season for some Utah enthusiasts on Monday as a huge crane lifted boats out of the Great Salt Lake State Park Marina, where officials say the water is at its lowest level for more than 50 years. Picture taken August 4, 2014. REUTERS/George Frey (UNITED STATES - Tags: ENVIRONMENT) 

A tumble weed sits on a mud flat where water used to be next to the Great Salt Lake Marina west of Salt Lake City, Utah, August 4, 2014. The Great Salt Lake water levels are expected to be the lowest since 1963 because of a prolonged drought in Utah. REUTERS/George Frey (UNITED STATES - Tags: ENERGY ENVIRONMENT) 

Mud flats sit where water use to be next to the Great Salt Lake Marina west of Salt Lake City, Utah, August 4, 2014. The Great Salt Lake water levels are expected to be the lowest since 1963 because of a prolonged drought in Utah. REUTERS/George Frey (UNITED STATES - Tags: ENERGY ENVIRONMENT) 

Mud flats surround the historic Saltair Dance Hall where water use to be, next to the Great Salt Lake Marina west of Salt Lake City, Utah, August 4, 2014. The Great Salt Lake water levels are expected to be the lowest since 1963 because of a prolonged drought in Utah. REUTERS/George Frey (UNITED STATES - Tags: ENERGY ENVIRONMENT) 

Lines mark the sand during low tide in the Loire Estuary in this aerial view with cabins and their tradition hanging fish nets in Paimboeuf, western France, May 15, 2014. REUTERS/Stephane Mahe (FRANCE - Tags: TRAVEL) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 9, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 9, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT TPX IMAGES OF THE DAY) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths play "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

Youths take a break from playing "futelama" or mud soccer, on tidal flats near the mouth of the Amazon river in Macapa, Amapa state, May 11, 2014. Brazilians from this region play anything from pick up games to organized tournaments of futelama throughout the year. The 2014 World Cup will be held in Brazil starting on June 12. Picture taken May 11, 2014. REUTERS/Paulo Santos (BRAZIL - Tags: SPORT SOCCER WORLD CUP ENVIRONMENT) 

A cargo ship passes by as competitors take part in a handball match during the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. Picture taken July 28. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY TPX IMAGES OF THE DAY) 

Competitors wait to wash-off after their handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY) 

Competitors wearing fancy dress prepare for the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY) 

Competitors take part in a handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY) 

Competitors fight for the ball during a handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY) 

Competitors fight for the ball during a handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY) 

A competitor saves the ball during a handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY TPX IMAGES OF THE DAY) 

Competitors fight for the ball during a handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY) 

Competitors fight for the ball during a handball match at the so-called Mud Olympics (Wattoluempiade) on the mud flats of Brunsbuettel along the North Sea coast July 28, 2013. Some 38 teams with 400 participants competed in the annual charity games on Sunday. REUTERS/Fabian Bimmer (GERMANY - Tags: SPORT SOCIETY TPX IMAGES OF THE DAY) 

A woman carries a bucket containing shellfish as she walks on the reef-mud flats of the lagoon at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT SOCIETY POLITICS) 

Women use forks to dig for shellfish on the reef-mud flats of the lagoon at South Tarawa in the central Pacific island nation of Kiribati May 24, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT SOCIETY POLITICS) 

A woman uses a fork to dig for shellfish on the reef-mud flats of the lagoon at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. REUTERS/David Gray (KIRIBATI) 

A woman uses a fork to dig for shellfish on the reef-mud flats of the lagoon located at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT SOCIETY POLITICS) 

Women dig for shellfish on the reef-mud flats of the lagoon at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT SOCIETY POLITICS) 

A boat sits on a reef-mud flat close to a lagoon at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. Kiribati consists of a chain of 33 atolls and islands that stand just metres above sea level, spread over a huge expanse of otherwise empty ocean. With surrounding sea levels rising, Kiribati President Anote Tong has predicted his country will likely become uninhabitable in 30-60 years because of inundation and contamination of its freshwater supplies. Picture taken May 23, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT POLITICS SOCIETY)

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A dog sits in the shade of a mangrove tree as a woman uses a fork to dig for shellfish on the reef-mud flats of a lagoon located at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. Kiribati consists of a chain of 33 atolls and islands that stand just metres above sea level, spread over a huge expanse of otherwise empty ocean. With surrounding sea levels rising, Kiribati President Anote Tong has predicted his country will likely become uninhabitable in 30-60 years because of inundation and contamination of its freshwater supplies. Picture taken May 23, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT POLITICS SOCIETY)

ATTENTION EDITORS: PICTURE 07 OF 42 FOR PACKAGE 'KIRIBATI - GONE IN 60 YEARS'. SEARCH 'KIRIBATI' FOR ALL IMAGES 

A woman uses a fork to dig for shellfish on the reef-mud flats of a lagoon at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. Kiribati consists of a chain of 33 atolls and islands that stand just metres above sea level, spread over a huge expanse of otherwise empty ocean. With surrounding sea levels rising, Kiribati President Anote Tong has predicted his country will likely become uninhabitable in 30-60 years because of inundation and contamination of its freshwater supplies. Picture taken May 23, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT POLITICS SOCIETY TPX IMAGES OF THE DAY)


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Young boys cover each other in reef-mud near the village of Ambo on South Tarawa in the central Pacific island nation of Kiribati May 25, 2013. Kiribati consists of a chain of 33 atolls and islands that stand just metres above sea level, spread over a huge expanse of otherwise empty ocean. With surrounding sea levels rising, Kiribati President Anote Tong has predicted his country will likely become uninhabitable in 30-60 years because of inundation and contamination of its freshwater supplies. Picture taken May 25, 2013. REUTERS/David Gray (KIRIBATI - Tags: ENVIRONMENT POLITICS SOCIETY)

ATTENTION EDITORS: PICTURE 05 OF 42 FOR PACKAGE 'KIRIBATI - GONE IN 60 YEARS'. SEARCH 'KIRIBATI' FOR ALL IMAGES 

Chad Coffin, (L) and Connor O'Neil are digging for clams in Casco Bay in Freeport, Maine May 30, 2013. An invasion of European green crabs, encouraged by rising ocean temperatures, is eating its way north through Maine’s clam flats, threatening the state’s third-largest fishery and an iconic summer treat for tourists. REUTERS/Dave Sherwood (UNITED STATES - Tags: ANIMALS ENVIRONMENT SCIENCE TECHNOLOGY) 

An invasive European green crab is pictured in Casco Bay in Freeport, Maine May 30, 2013. An invasion of European green crabs, encouraged by rising ocean temperatures, is eating its way north through Maine’s clam flats, threatening the state’s third-largest fishery and an iconic summer treat for tourists. REUTERS/Dave Sherwood (UNITED STATES - Tags: ANIMALS ENVIRONMENT SCIENCE TECHNOLOGY) 

A lone tree can be seen across mud flats located on the outskirts of the town of Nelson in New Zealand September 30, 2011. REUTERS/David Gray (NEW ZEALAND - Tags: ENVIRONMENT SOCIETY) 

A man runs along mud flats located on the outskirts of the town of Nelson in New Zealand September 30, 2011. REUTERS/David Gray (NEW ZEALAND - Tags: ENVIRONMENT SOCIETY) 

Army soldiers remove mud as they work to restore an apartment damaged by a landslide in Seoul July 28, 2011. South Koreans were cautioned about rogue landmines and explosives on Thursday after a series of deadly landslides in and around the capital Seoul swamped military sites, defence officials said. At least 67 people are dead or missing from the landslides and flashfloods caused by the heaviest rainfalls in a century to hit the Seoul region, home to about 25 million people. REUTERS/Truth Leem (SOUTH KOREA - Tags: DISASTER ENVIRONMENT IMAGES OF THE DAY) 

Elementary school students crawl forward at a mud flat as they participate in a summer military camp for civilians at the Cheongryong Self-denial Training Camp run by retired marines in Ansan, about 40 km (25 miles) southwest of Seoul, July 21, 2011. Thirty seven students are in the three-day camp to strengthen their spirit and body. REUTERS/Jo Yong-Hak (SOUTH KOREA - Tags: MILITARY EDUCATION SOCIETY)