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)

“Diver in Magic Kingdom”. Green Lake (Grüner See) is located Tragöss Austria. In spring snowmelt raises the lake level about 10 meters. This phenomenon, which lasts only a few weeks covering the hiking trails, meadows, trees. The result is magical to watch diving landscapes. Photo location: Grüner See at Tragöss, Austria. (Photo and caption by Marc Henauer/National Geographic Photo Contest)

Small transportation boats, known as bumboats, leave trails of light as they travel across Marina Bay past the skyline of Singapore in this photo taken in 2004. Singapore holds a Jubilee weekend from 7 to 10 August to celebrate the 50th anniversary of its independence. Fifty years ago, hundreds of small boats lined the Singapore river in the city centre. Today, most small boats are gone, except a handful of neon-lit tourist ferries. Maritime trade is still the backbone of the city-state but after decades of rapid growth Singapore, which at less than half the size of London is among the world’s most densely populated nations, is also a popular tourist destination and a thriving global financial hub. (Photo by Edgar Su/Reuters)

A woman wears a face mask on her chin and walks past a cake depicting the coronavirus on display at the annual cake show organized as part of new year celebrations in Bengaluru, India, Tuesday, December 29, 2020. India's confirmed coronavirus cases have crossed 10 million with new infections dipping to their lowest levels in three months, as the country prepares for a massive COVID-19 vaccination in the new year. (Photo by Aijaz Rahi/AP Photo)

Rescuers and mother surround Adnan Mohammet Korkut after he was rescued in Gaziantep, southern Turkey, early Friday, February 10, 2023. The teenager was pulled largely unscathed from beneath the rubble of a collapsed building in the Turkish city of Gaziantep early Friday, in a dramatic rescue that belied the reality that the chances of finding many more survivors four days after a catastrophic earthquake killed tens of thousands are shrinking fast. (Photo by IHA via AP Photo)

Motorcycle fans dressed as Santa Claus ride near Charlottenburg Palace (Schloss Charlottenburg)during the 25th annual “Santa Claus On Road” Berlin Bike Tour, to deliver gifts to the needy on December 10, 2022 in Berlin, Germany. Some 200 riders with vehicles decorated with lights and mini-Christmas trees took part in the annual event on its 25 year. Anyone may ride along, whether on motorcycle, trike or quad, as long as the vehicle is decorated accordingly. (Photo by Omer Messinger/Getty Images)

A member of the Africa Roho Msalaba church throws a 2 month old baby into the air during the “Throwing babies into the air” ritual in Kibera Slum of Nairobi, Kenya on March 10, 2024. The babies of the members of the Africa Roho Msalaba church, who are not taken out of the house until they are 2 months old and are not allowed to be seen by strangers, are introduced to the community by being paraded through the streets with the 'throwing babies in the air' ritual. (Photo by Edwin Ndeke/Anadolu via Getty Images)

Flight attendants of Zhejiang Loong Airlines undergo rigorous posture training on March 14, 2022 in Hangzhou, Zhejiang Province of China. A total of 300 flight attendants received an etiquette training, including 13 courses for Hangzhou 2022 Asian Games, which will be held from Sept. 10 to 25, 2022 in Hangzhou. (Photo by Wang Gang/China News Service via Getty Images)