Victoria Gill

And that could reveal some vital clues about the health of the Antarctic marine food chain. Victoria Gill.

And that could reveal some vital clues about the health of the Antarctic marine food chain. Victoria Gill.

The discovery that oxygen, which is vital for life, was being made in the dark on the seafloor confounded marine scientists when it was announced.

The discovery that oxygen, which is vital for life, was being made in the dark on the seafloor confounded marine scientists when it was announced.

The discovery that oxygen, which is vital for life, was being made in the dark on the seafloor confounded marine scientists when it was announced. It's widely accepted the gas is produced by plants in sunlight using photosynthesis. But down where sunlight can't penetrate... Scientists found oxygen levels going up.

The discovery that oxygen, which is vital for life, was being made in the dark on the seafloor confounded marine scientists when it was announced. It's widely accepted the gas is produced by plants in sunlight using photosynthesis. But down where sunlight can't penetrate... Scientists found oxygen levels going up.

The seabed they studied is covered with nodules of metal that have built up naturally over millions of years. It's these nodules that researchers say produce the gas. If they detect oxygen they'll then carry out detailed experiments to understand exactly how it's being made.

The seabed they studied is covered with nodules of metal that have built up naturally over millions of years. It's these nodules that researchers say produce the gas. If they detect oxygen they'll then carry out detailed experiments to understand exactly how it's being made.

This is a story with some very tiny main characters, the Desertus Island land snails. They were rescued from the brink of extinction and brought to Chester Zoo, where they've been living and breeding inside this converted shipping container.

This is a story with some very tiny main characters, the Desertus Island land snails. They were rescued from the brink of extinction and brought to Chester Zoo, where they've been living and breeding inside this converted shipping container.

There are two snail species that the team are bringing back to their wild island home off the coast of Portugal. Discular snails and the even smaller Geometra. They're prepared for their journey with a little scientific makeover.

There are two snail species that the team are bringing back to their wild island home off the coast of Portugal. Discular snails and the even smaller Geometra. They're prepared for their journey with a little scientific makeover.

Why do they need to be marked?

Why do they need to be marked?

The desertus islands close to Madeira in Portugal are their destination and their natural home. The largest of the islands, where the last snails were found, has had its habitat decimated, eaten away by goats, rats and mice that were brought here by people. So the team has transported the snails to the protected neighbouring island of Bugio. It's meant a long and precarious journey.

The desertus islands close to Madeira in Portugal are their destination and their natural home. The largest of the islands, where the last snails were found, has had its habitat decimated, eaten away by goats, rats and mice that were brought here by people. So the team has transported the snails to the protected neighbouring island of Bugio. It's meant a long and precarious journey.

After waiting for the ideal cooler evening conditions, it's finally time to set the snails free.

After waiting for the ideal cooler evening conditions, it's finally time to set the snails free.

This is a small but significant part of a mission to restore the natural habitat and wildlife on these mountainous Atlantic islands. If it goes well, more snails will be brought here next year, each bringing a small splash of colour back to their habitat. Victoria Gill.

This is a small but significant part of a mission to restore the natural habitat and wildlife on these mountainous Atlantic islands. If it goes well, more snails will be brought here next year, each bringing a small splash of colour back to their habitat. Victoria Gill.