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)

An orphaned giraffe nuzzling a wildlife keeper at Sarara camp in Kenya, one of 70 pictures being sold by Prints for Nature (printsfornature.com) to raise money for work by the Conservation International charity. This giraffe was rehabilitated and returned to the wild, as a number of others have done before him. Right now, giraffe are undergoing what has been referred to as a silent extinction. Current estimates are that giraffe populations across Africa have dropped 40 percent in three decades, plummeting from approximately 155,000 in the late 1980s to under 100,000 today. (Photo by Ami Vitale/National Geographic)

Members of the Coney Island Polar Bear Club warm up before swimming at the beach at Coney Island in New York, December 15, 2013. (Photo by Eric Thayer/Reuters)

An Indian woman reacts while performing yoga at a railway station on International Women's Day, organised by Heal-Station in association with Western Railway, in Mumbai, India, 08 March 2023. (Photo by Divyakant Solanki/EPA/EFE/Rex Features/Shutterstock)

Alaa Shabat lives with her six children in a tent erected inside the Austrian cemetery in Khan Younis, southern Gaza Strip, on November 13, 2025, after her husband became ill and unable to work. (Photo by Tariq Mohammad/APAImages/Rex Features/Shutterstock)

Gentoo penguins watching Christmas films at the Sea Life London aquarium on November 30, 2020. The attraction has installed two TVs, showing festive films, outside the penguin enclosure to prepare them for the stimulation of guests returning on Wednesday after the UK’s lockdown is lifted. (Photo by Yui Mok/PA Images via Getty Images)

Transgender woman Angeles Rojas enters a room at Banco Nación where she works in Buenos Aires, Argentina, Thursday, November 5, 2020. Rojas, 23, joined the most important public bank in Argentina this year as part of the trans labor quota that is part of the public policies in favor of the LGBT community that the South American country has implemented in the last decade. (Photo by Natacha Pisarenko/AP Photo)

People smeared with colors play Holi at Nandagram temple in Nandgoan village, 115 kilometers (70 miles) south of New Delhi, India, Wednesday, March 1, 2023. (Photo by Deepanshu Aggarwal/AP Photo)