John Chan / American avocet (Recurvirostra americana) foraging in salt marsh, Southern California, USA.

John Chan / Flock of Western sandpipers (Calidris mauri) taking flight from salt marsh, Southern California, USA.

Milan Radisics / Aerial shot of the Gemasolar Thermosolar Plant owned by Torresol Energy, it uses molten salt as its heat transfer fluid and energy storage medium to produce energy for up to 24 hours a day, Seville, S...

Milan Radisics / Aerial shot of the Gemasolar Thermosolar Plant owned by Torresol Energy, it uses molten salt as its heat transfer fluid and energy storage medium to produce energy for up to 24 hours a day, Seville,...

Juan Carlos Munoz / Aerial view of Salinas de Janubio, La Hoya, Lanzarote Island, Canary Islands. December 2018.

Daniel Heuclin / Vicuna (Vicugna vicugna), five running across salt flat with mountain in background. Salar de Ascotan, Chile. September 2018.

Paul Souders/ Worldfoto / Red algae and salt formations, Lake Natron, Ol Doinyo Lengai, Tanzania

Vincent Grafhorst / Salt flat, Lake Asale, Danakil Depression, Ethiopia

Vincent Grafhorst / Dromedary (Camelus dromedarius) caravan transporting salt across salt flat, Lake Asale, Danakil Depression, Ethiopia

Jack Dykinga / Eroded salt laden sandstone 'fins' in incredible sculpted forms comprise an area know as 'Little Finland.' Gold Butte National Monument, Nevada, USA. President Barack Obama designated the monument on...

Jack Dykinga / Eroded salt laden sandstone 'fins' in incredible sculpted forms comprise an area know as 'Little Finland.' Gold Butte National Monument, Nevada, USA. President Barack Obama designated the monument on...

Jack Dykinga / Eroded salt laden sandstone 'fins' in incredible sculpted forms comprise an area know as 'Little Finland.' Gold Butte National Monument, Nevada, USA. President Barack Obama designated the monument on...