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 hummingbird feeds on the nectar from a Mimosa tree in Saugus, Massachusetts on July 30, 2020. (Photo by Joseph Prezioso/ZUMA Wire/Rex Features/Shutterstock)

The Villarrica volcano shows signs of activity, as seen from Pucon, some 800 kilometers south of Santiago, on November 21, 2022. Villarrica volcano is among the most active in South America. (Photo by Mario Quilodran/AFP Photo)

Soldiers of Ukraine's National Guard 1st brigade Bureviy (Hurricane) fire a recoilless cannon during combat training at a military training ground in the north of Ukraine Friday, November 3, 2023. (Photo by Efrem Lukatsky/AP Photo)

This photo taken on December 2, 2023 shows pandas eating inside their enclosure at a zoo in China's southwestern Chongqing municipality. (Photo by AFP Photo/China Stringer Network)

A common gallinule runs across the water to escape a nearby alligator at Green Cay Nature Center in Boynton Beach, Florida on September 4, 2025. Unlike most waterbirds, gallinules have long toes that allow them to walk on floating vegetation. The species is known for its loud, cackling calls that often echo through wetlands. (Photo by Ronen Tivony/NurPhoto/Rex Features/Shutterstock)

Kieran Woolley of Australia crashes into a cameraman during mens park skateboard at the Olympics at Ariake Urban Park, Tokyo, Japan on August 5, 2021. (Photo by Lisi Niesner/Reuters)

2016 Rio Olympics, Swimming, Preliminary, Men's 100m Backstroke, Heats, Olympic Aquatics Stadium, Rio de Janeiro, Brazil on August 7 2016. Christopher Reid (RSA) of South Africa competes. (Photo by Dominic Ebenbichler/Reuters)