Written by Amy Woodyatt, CNN

A gentoo penguin flees for its life as a snarling leopard seal bursts out of the water. A curious young gray whale moves toward a stray pair of hands reaching down from a tourist boat. A washed-up beach chair forms a fatal noose around the neck of a sea turtle.

These stunning images have been submitted as part of London's Natural History Museum's Wildlife Photographer of the Year competition, which has been running for 55 years.

Nearly 50,000 entries from professional and amateur photographers across 100 countries were submitted to the prestigious award, of which the overall winners will be announced on October 15.

"For more than fifty years this competition has attracted the world's very best photographers, naturalists and young photographers, but there has never been a more important time for audiences all over the world to experience their work in our inspiring and impactful exhibition," Tim Littlewood, Director of Science at the Natural History Museum and member of the judging panel, said in a statement.

"Photography has a unique ability to spark conversation, debate and even action. We hope this year's exhibition will empower people to think differently about our planet and our critical role in its future," he added.

After the awards ceremony, the images will be displayed at London's Natural History Museum from October 18 and will later be showcased on an international tour.

A gentoo penguin flees for its life as a leopard seal bursts out of the water. Credit: Eduardo Del Álamo/Wildlife Photographer of the Year

A newborn hippo, just days old, was keeping close to its mother in the shallows of Lake Kariba, Zimbabwe, when a large bull suddenly made a beeline for them. He chased the mother, then seized the calf in his huge mouth, clearly intent on killing it. Credit: Adrian Hirschi/Wildlife Photographer of the Year

An ever-adaptable raccoon pokes her bandit-masked face out of a 1970s Ford Pinto on a deserted farm in Saskatchewan, Canada. In the back seat, her five playful kits trill with excitement. Credit: Jason Bantle/Wildlife Photographer of the Year

This beach scene at Alabama's Bon Secour National Wildlife Refuge looks appealing at first glance: blue sky, soft sand and a Kemp's ridley sea turtle. But as the photographer got closer he could see the fatal noose around the turtle's neck attached to the washed-up beach chair. Credit: Matthew Ware/Wildlife Photographer of the Year

Slender stems of Eurasian watermilfoil, bearing whorls of soft, feathery leaves, reach for the sky from the bed of Lake Neuchâtel, Switzerland. Credit: Michel Roggo/Wildlife Photographer of the Year