A young man looks over his shoulder as men watching a soccer match in a nearby bar ask why he isn't watching the game, while walking with his date during the men's gold medal soccer match between Brazil and Germany during Rio 2016 on Saturday, August 20, 2016. (Photo by Aaron Ontiveroz/The Denver Post)

Elephants dust themselves with soil at Taigan safari park in Belogorsk, Crimea on May 4, 2021. (Photo by Alexey Pavlishak/Reuters)

Pusha the cat, which adopted four bereaved baby squirrels and currently feeds and lives with them, lies at a local park of miniatures in Bakhchisaray, Crimea on April 25, 2019. (Photo by Alexey Pavlishak/Reuters)

Two Inuit children at Point Barrow, Alaska, holding the tusks of a large walrus, probably killed for food, circa 1930. (Photo by General Photographic Agency/Getty Images)

North Korean traffic police women chat next to a residential building while off duty Tuesday, October 18, 2016, in Pyongyang, North Korea. (Photo by Wong Maye-E/AP Photo)

Undated handout photo of members of Ballet Ireland during a photocall on Edinburgh's Calton Hill before taking part in the Edinburgh Festival 2018 in Edinburgh, Scotland. Issue date: Tuesday, August 7, 2018. (Photo by Julie Howden/Culture Ireland/PA Wire)

A man and a dog bathe in a fountain during celebrations of Paratroopers' Day in Moscow' s Gorky Park on August 2, 2017. Russia' s Airborne Troops (Blue Berets) celebrate their professional holiday on the Day of Elijah the Prophet, their Patron. (Photo by Stanislav Krasilnikov/TASS)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)