June 8 was designated as World Oceans Day by the United Nations in 2008.

Oceans cover most of our planet. They provide much of the oxygen we need to survive, regulate weather and temperature, and are home to countless plants and animals. Yet, the oceans face continued threats from pollution, overfishing, and warming temperatures.

The pictures below remind us of the ocean's beauty and how important it is to protect and preserve this system.

A sea turtle says hi.

Turtle nicolas.voisin44/Shutterstock

A humpback whale passes near an iceberg.

whale Visit Greeland/Flickr

A brassy leather coral spotted in the Maldives. Brassy Leather Coral. Neville Wootton/Flickr

An endangered manatee swims with a school of fish in Florida. Manatee Ryan Hagerty, USFWS

An octopus is photographed on the Caribbean reef.

Octopus Isabelle Kuehn/Shuttertock

A diver swims under a tiger shark.

Shark frantisekhojdysz/Shutterctock

A grey seal swims underwater near the Farne Islands off the coast of northern England.

Seal REUTERS/Nigel Roddis

A body surfer punches through a wave at the Ehukai sandbar near the surf break known as 'Pipeline' on the North Shore of Oahu, Hawaii.

surfer REUTERS/Hugh Gentry

A whale shark, the world's largest fish is seen in Mozambique.

swimming with whale sharks mozambique Shutterstock

A red-reef hermit crab is captured in the Netherlands.

Hermit crab Laszlo Ilyes

A scuba diver swims near a school of swirling jacks.