Teeming with images of spectacular underwater scenes from around the world, Call of the Blue is the culmination of a five-year project by the photographer and ocean conservationist Philip Hamilton. This groundbreaking book includes contributions from acclaimed scientists and ocean “guardians”, who reveal what drove them to answer the call of the blue. (Photo by Philip Hamilton/The Guardian)

The Turkish merchant ship Efe Murat is driven aground in strong winds in Bari, Italy on February 25, 2019. (Photo by De Giglio/Fotogramma/Ropi/ROPI via ZUMA Press/Rex Features/Shutterstock)

A security man keeps guard during Malawi's President elect Arthur Peter Mutharika swearing in ceremony at Kamuzu Stadium in Blantyre on May 28, 2019, after a contentious election marred by allegations of fraud and vote-rigging. The Malawi Electoral Commission announced on Monday that Mutharika, who heads the ruling Democratic Progressive Party (DPP), had narrowly won last week's vote after an injunction barring the release of the results was lifted. (Photo by Amos Gumulira/AFP Photo)

Some dozens of long-finned pilot whales lay dead on a remote beach in Iceland after they were discovered by tourists sightseeing in the Snaefellsnes Peninsula in western Iceland aboard a helicopter, Thursday July 18, 2019. The whales were concentrated in one spot on the beach, many partially covered by sand. (Photo by David Schwarzhans via AP Photo)

A pro-government supporter scuffles with an anti-extradition supporter outside the office of pro-China lawmaker Junius Ho in Tsuen Wan in Hong Kong, China on July 22, 2019. Hong Kong demonstrators gathered for another weekend of protests against the controversial extradition bill and with a growing list of grievances, maintaining pressure on Chief Executive Carrie Lam. (Photo by Edgar Su/Reuters)

A string art picture made by artist Ani Abakumova in a workshop in the village of Romashkovo in Moscow Region, Russia on August 2, 2019. Ani Abakumova and her husband Andrei Abakumov create string art replicas of famous paintings. Andrei makes computer calculations that show patterns for future images, then Ani winds coloured strings around nails hammered around a plywood board. (Photo by Anton Novoderezhkin/TASS)

Robots serve trays with food to customers waiting at the Robot theme restaurant in Bangalore, India, 17 August 2019. Six robots are deployed as waiters at the the robot-themed Robot restaurant where each table is equipped with a tablet to place one's order. (Photo by Jagadeesh N.V./EPA/EFE)

Listed as endangered on the IUCN red list of threatened species, a humphead wrasse, or Napoleon fish, swims in an aquarium during an event in Tokyo's shopping district of Ginza on August 5, 2019. (Photo by Kazuhiro Nogi/AFP Photo)