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)

A biker passes by a pair of mailboxes in the Capitol Hill neighborhood November 6, 2012 in Denver, Colorado. Colorado is considered by most experts to be one of the key battleground state in this year's presidential election. (Photo by Marc Piscotty/AFP Photo)

A child dressed as a Roman centurion poses during a parade to mark the anniversary of the foundation of Rome in 753 BC, on April 23, 2017 in Rome. (Photo by Alberto Pizzoli/AFP Photo)

An operator adjusts a film projector during a wedding party in Bogor, Indonesia, February 18, 2017. Indonesian entrepreneur Kamaluddin loves the gritty look of old 35-millimeter film so much that he spends most of his nights screening vintage movies at weddings and parties around Jakarta, the capital. (Photo by Reuters/Beawiharta)

US Navy personnel walk on the flight deck aboard the USS Nimitz (CVN-68) aircraft carrier during its port visit to Busan on March 28, 2023. (Photo by Anthony Wallace/AFP Photo)

A golden snub-nosed monkeys (Rhinopitheque de Roxelane) looks through its enclosure after quarantine during its presentation at the Beauval Zoopark in Saint-Aignan Central France, on May 7, 2025. ZooParc de Beauval (Loir-et-Cher) welcomed three golden snub-nosed monkeys on April 3, 2025, an endangered species from China, as part of a conservation program, becoming the first zoo outside Asia to house these long-haired, red-furred primates with bluish faces. (Photo by Guillaume Souvant/AFP Photo)

Matilda Thurston 10, enjoys a warm day at Hathersage Swimming Pool in Hathersage on April 27, 2025. A mini heatwave is set to hit parts of the UK with temperatures reaching 27 degrees next week. (Photo by Ioannis Alexopoulos/London News Pictures)

A jaguar (Panthera onca) growls at the Mata Ciliar association, an organization for the conservation of biodiversity, in Jundiai, Sao Paulo state, Brazil on May 29, 2025. Twenty-five pumas and ten jaguars are currently recovering at the Brazilian Center for the Conservation of Neotropical Felines at Mata Ciliar, a site as large as 40 football fields where monkeys, wild dogs, maned wolves, ocelots, and other regional animals are also rehabilitated. (Photo by Nelson Almeida/AFP Photo)