Atmospheric shot of circling sharks scoops Underwater Photographer of the Year 2021

American Renee Capozzola has become the first female Underwater Photographer of the Year overall winner after her stunning image of blacktip reef sharks in French Polynesia scooped the award for 2021.

Capozzola's atmospheric shot of the marine predators cruising beneath seagulls at sunset beat more than 4,500 submissions from competitors across 68 countries in the annual contest.

A native of southern California, Capozzola has traveled all over the world with her camera, according to her website.

The winning image, "Sharks' Skylight," was taken on the Pacific island of Moorea in August.

"French Polynesia strongly protects its sharks, it is my favorite place to photograph them," she said in a statement released by the contest organizers. "I dedicated several evenings to photographing in the shallows at sunset, and I was finally rewarded with this scene: Glass-calm water, a rich sunset, sharks and even birds."

Posting news of her win on Facebook, Capozzola said she was "completely blown away and honored beyond words to have received this prestigious recognition."

She added: "Sharks are in danger of extinction so it is my hope that this picture will help increase awareness of the added legal protections sharks need throughout the world."

Alexander Mustard, chairman of the judges, said the awe-inspiring images from all the entrants offered "a much-needed escape into the underwater world."

Commenting on the overall winner, he said: "This is a photograph of hope, a glimpse of how the ocean can be when we give it a chance, thriving with spectacular life both below and above the surface."

Based in the UK, the annual competition -- running since 1965 -- celebrates photography beneath the surface of oceans, lakes, rivers and even swimming pools.

The competition has 13 categories, with themes such as macro, wide angle, behavior and wreck photography, as well as four categories for photos taken specifically in British waters.

Mark Kirkland was named British Underwater Photographer of the Year 2021 for his inner-city wildlife vision "While You Sleep," captured close to his home in Glasgow. Kirkland said the shot was a culmination of "lying stationary in darkness" for 25 hours over four nights.

"This small muddy pond is an unlikely haven for wildlife, squeezed between a housing estate, supermarket and factory. But for a few nights each year, while the city sleeps, it comes alive with frogs," he added.

Karim Iliya, from the US, was named Marine Conservation Photographer of the Year 2021 for "Crowded Island," an aerial view of a small island in Panama.

Highlighting conservation issues in the ocean, this is the first time the category was won by an above water image, organizers said.

"This densely inhabited village is a visual microcosm, a reminder of how humans across the planet are over-consuming space," said Iliya.

"Our relationship with nature and the importance of protecting it becomes very apparent when you look at our species from above and see how we monopolize space, forcing nature out."

Praising the image, judge Peter Rowlands said it was "a stark visual reminder of how we humans overrun the land, then overfish the surrounding sea."