Afghan police recruits undergo training at the Afghan Police Academy October 5, 2010 in Kabul, Afghanistan. (Photo by Majid Saeedi/Getty Images)

The winter sun rises over the Somerset Levels viewed from Glastonbury Tor on December 10, 2011 in Glastonbury, England. After being hit by winter storms this week, the UK is experiencing colder temperatures but high winds are forecast to return. (Photo by Matt Cardy/Getty Images)

A child attends a training session in a swimming pool on July 10, 2007 in Wuhan of Hubei Province, China. (Photo by China Photos/Getty Images)

A street food vendor waits for customers on a footpath in New Delhi, India, November 27, 2018. (Photo by Anushree Fadnavis/Reuters)

Cooler temperatures begin this week as a polar vortex brings much colder conditions with the chance of snow for Snowdonia, Ogwen Valley, North Wales on 22nd October 2018. The Ogwen Valley and Tryfan Mountain looking splendid in the Autumn sunrise. (Photo by DGDImages/Alamy Live News)

A boatman rests on his boat in the flooded Ganges river under the Shastri bridge at Daraganj Ghat, in Allahabad, India on August 22, 2019. (Photo by Sanjay Kanojia/AFP Photo)

A rainbow rises over flooded fields after the Rivers Thames and Churn burst their banks, in Cricklade, western England on January 3, 2024, following Storm Henk which brought strong winds and heavy rain across much of the country. (Photo by Adrian Dennis/AFP Photo)

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)