A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)

In this July 11, 2018 photo, members of a private photo studio take pictures of a woman in Havana, Cuba. New rules for private business indicate that the government has ruled out going further to open private business, such as allowing small and medium enterprises and authorizing business to operate as societies. Currently, private business licenses are granted only to individuals, and only one license per person. (Photo by Desmond Boylan/AP Photo)

Christian Bale poses for a fan at the 25th annual Screen Actors Guild Awards at the Shrine Auditorium & Expo Hall on Sunday, January 27, 2019, in Los Angeles. (Photo by Mario Anzuoni/Reuters)

Split-view of a killer whale at sunrise off the coast of Northern Norway. At least half of the world’s killer whale populations are doomed to extinction due to pollution of the oceans, a new study says. (Photo by Audun Rikardsen/Science)

A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

Trick rider Kendel Sampson performs during the trick riding session of the RAM Rodeo in Warkworth, Ontario, on August 1, 2013. The teenage Encore Presentation Trick Riders perform daring stunts every rodeo season in towns throughout Canada. (Photo by Norm Betts/Barcroft Media)

An animal rights activist, wrapped in packaging labelled “carne humana” (human meat), participates in a protest against meat consumption to promote vegetarianism in central Barcelona, in Spain, May 22, 2016. (Photo by Albert Gea/Reuters)

A rusty revolver is seen near the body of a man, who police said was killed by police operatives, and two sachets of “Shabu” or methampethamine chloride were found on his pockets in Manila, Philippines August 17, 2017. (Photo by Erik De Castro/Reuters)