Girls prepare to take part in a mermaid lesson in Rio de Janeiro, Brazil May 28, 2017. Women in Brazil are not unique in their affinity for mermaiding. Classes are held as far away as Texas and some folks wonder if mermaiding will be the next fitness craze. (Photo by Pilar Olivares/Reuters)

Grey seals show their playful side while swimming off the English coast, UK in the last decade of May 2025. (Photo by Brian Matthews/Solent News)

Entitled Feasting at Sunset, this photo of a Brandt’s cormorant among pilchards was the winner of the Birds in the Environment category in the 2025 Bird Photographer of the Year competition. (Photo by Franco Banfi/The Guardian)

The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

Men are sent down into the sludge to clear the sewers in the Bangladeshi capital Dhaka on May 23, 2018. The people who do the work aren’t even given any protective clothing or goggles and have to dig out the clogged-up muck with a stick or their bare hands. (Photo by Rehman Asad/Barcroft Media)

Impressive images of these alien-like creatures were captured underwater – photographer Cai Songda is a keen diver and did not miss the chance to snap pictures of the unique “aliens”. Here: A Tremoctopus Gracilis in the waters around Anilao, Philippines. (Photo by Cai Songda/Caters News Agency)

Fisherwomen laying barrels with salt in preparation for herring curing, 1937. (Photo by Topical Press Agency)

A Border Collie competes in the Flyball during The World Dog Games at Acer Arena on October 31, 2009 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)