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)

A “creuseur”, or digger, a plastic lantern on his head, readies to enter a copper and cobalt mine in Kawama, Democratic Republic of Congo on June 8, 2016. Cobalt is used in the batteries for electric cars and mobile phones. Working conditions are dangerous, often with no safety equipment or structural support for the tunnels. The diggers say they are paid on average US$2-3/day. (Photo by Michael Robinson Chavez/The Washington Post)

In this Sunday, March 11, 2017 photo, children fight in a boxing ring in Chitungwiza, Zimbabwe. Zimbabwean boys as young as 10 hurry every weekend to a boxing ring whose nickname, Wafa Wafa, in the local Shona language suggests that whoever enters will be lucky to come out alive. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Billions of newly hatched locusts are spreading throughout Israel's South. The young locusts identified in the Negev Desert area are the offspring of locust swarms that entered Israel from Egypt in March. (Photo by Eliahu Hershkovitz/Haaretz)

An Israeli jail authority officer escorts a prison van containing Palestinian prisoners as it enters Hasharon jail on October 16, 2011 in Tel Mond, Israel. IDF soldier Gilad Shalit is to be freed from 5 years of captivity in Gaza in an exchange deal which will see the release of 477 Palestinian prisoners in an initial deal with another 550 to freed after the return of Shalit. (Photo by Uriel Sinai/Getty Images)

A photo provided by the Atlanta Journal-Constitution shows Atlanta police officer T. R. Coxe removing painted material of a large swastika featuring a likeness of Republican presidential candidate, Donald Trump, along the northbound Buford Highway Connector just south of the Piedmont exit, in Atlanta, Georgia, USA, 09 December 2015. Just days after Donald Trump's call to ban Muslims from entering the United States, someone painted large swastikas featuring the Republican presidential candidate's face on at least two northeast Atlanta bridge supports. The symbol, which includes a cartoon of Trump sporting a Hitler-like mustache, was painted along the Buford Highway Connector. A second, similar image was found on a concrete bridge support on nearby Piedmont Road. Trump said in a statement released on 07 December that there should be a total and complete shutdown of Muslims entering the United States. (Photo by John Spink/EPA/AJC)

Israeli soldiers pray at dawn as the conflict between Palestine and Gaza enters its seventh day on November 20, 2012 on Israel's border with the Gaza Strip. Hamas militants and Israel are continuing talks aimed at a ceasefire as the death toll in Gaza reaches more than 100 and also three Israelis killed by rockets fired by Palestinian militants. (Photo by Christopher Furlong)

Rowers enter in Canaregio river during the 42nd Venice Vogalonga on May 15, 2016 in Venice, Italy. 42 years ago a group of Venetians, both amateur and professional rowers, came up with an idea of non-competitive race in which any kind of rowing boat can take part. The first Vogalonga began with the message to protest against the growing use of powerboats in Venice and the swell damage they do to the historic city. (Photo by Awakening/Getty Images)