Leatherback turtles are frequent visitors to the seas around Scotland

The Joint Marine Programme Scotland says the country is home to the second biggest fish in the world and its seas are visited by leatherback turtles.

But it insists the marine environment is under threat because of litter, pollution and over fishing.

World Ocean Day aims to highlight that 50% of wildlife is found in the sea.

The Joint Marine Programme in Scotland is a partnership between the Scottish Wildlife Trust and WWF Scotland.

It has been tasked with ensuring the conservation of marine wildlife and providing a healthy marine and coastal environment.

'Day to celebrate'

Laura Bateson, from the programme team, said: "Most people look out at the seas in Scotland and imagine them to be grey and lifeless.

"However, Scotland has more than 8,000 marine plants and animals.

"There are deep water corals, ancient seaweed beds and some amazing underwater features that very few people ever get to see.

"World Ocean Day is a day to celebrate that natural heritage and to let more people know exactly what it out there, and what they can do to keep it clean and healthy for our future generations."

The five marine mysteries include facts such as:

• The marine environment makes up 53% of Scotland's territory and generates �14bn of Scottish GDP each year

• Scotland has its own unique cold water corals known as the Darin Mounds. They are found at depths of 1,000m and the reefs are up to 5m high and 100m wide

• Scotland's waters are home to the second biggest fish in the world, the basking shark. It can be found all around the Scottish coastline during the summer months

• There are internationally important seabirds including the largest gannet colony in the world at St Kilda

• Leatherback turtles regularly visit the cold Scottish waters. The creatures are more than 100 millions years old and have out-lived the dinosaurs.