World Oceans Day: 20 remarkable images of our most precious resource

The world's oceans face an unprecedented challenge from man-made threats

Surf instructor Tommy Olsen teachers beginners how to ride the waves in Norway's Lofoten Island in the Arctic Circle. AFP

Greenpeace's 'Arctic Sunrise' ship navigates through floating ice in the Arctic Ocean. Reuters

A snorkler identifies species growing on the hull of a ship during a marine biology survey in the Indian Ocean in False Bay, Cape Town. EPA

An iceberg in the western Antarctic peninsula. AFP

Millions of pieces of plastic, micro plastics and debris are visible in the ocean as a free diver collects litter during the Big Ocean Clean Up in Hermanus, South Africa. EPA

Bioluminescent algae glows in the crashing waves as a lifeguard tower sits on an empty beach in Encinitas, California. Reuters

Two men prepare a net to fish in the port of Palo Seco, in the Gulf of Montijo in Mariato, Veraguas, Panama. EPA

A sailor assigned to Naval Special Warfare Group 2 conducting military dive operations in the Atlantic Ocean off the US east coast. AFP

The Indian Ocean laps the Koattey wetlands in Hithadhoo, Maldives. Getty Images

A plastic bottle floats in the water. Photo: National Geographic Abu Dhabi

World Oceans Day helps to raise awareness of issues blighting the environment, such as plastic pollution. Photo: National Geographic Abu Dhabi

This powerful image highlights the growing problem of plastic pollution. Photo: National Geographic

A species of dolphin, known as the false killer whale, thrives in tropical and subtropical oceans. Photo: Dr Csaba Geczy

More than 300 kilograms of ghost nets were retrieved by the team of divers cleaning up the ocean in the Mergui archipelago, Myanmar.

Fish swim along the edges of a coral reef off Great Keppel Island in Australia. AP

This satellite image from the US National Oceanic and Atmospheric Administration shows a plume of smoke from the Saddleridge wildfire streaming out over the Pacific Ocean. AP

The temperature of the world’s oceans is rising dramatically. Reuters

From the Great Barrier Reef to the Arabian Gulf and beyond, protecting the seas and oceans is about as urgent an issue as you could hope to find, marine scientists say. Getty Images

People scoop leaked oil from the vessel 'MV Wakashio' that ran aground and caused oil leakage near Blue Bay Marine Park in south-east Mauritius. AFP

This award-winning image from 2017 proved a striking example of the damage being done to the ocean by discarded rubbish. Photo: Justin Hofman

Environmental campaigners and other nature lovers will come together on Tuesday to celebrate the wonders of the world's oceans and send out a vital message over the need to preserve them for generations to come.

World Oceans Day was established by the UN and marked for the first time on June 8, 2009.

It aims to raise awareness of the importance of the Earth's precious resource, encourage sustainable development and deliver a call to action over threats such as global warming and pollution.

Oceans cover three quarters of the planet's surface, contain 97 per cent of its water, and represent 99 per cent of the living space on the planet by volume, according to UN figures.

The theme of World Oceans Day 2021 is The Ocean: Life and Livelihoods.

It aims to shed light on the key role of the ocean as a life source, supporting humanity and marine life.