The Afon Teifi is set to feature in a brand new BBC One series this month.

Wonders of the Celtic Deep is a brand new landmark natural history series, narrated by Dame Siân Phillips, that showcases the remarkable wildlife that can be found in and beside the sea that surrounds the spectacular Welsh coastline.

In the first episode, Coasts: Life on the Edge meet animals that make their homes in this challenging environment - where the land and the ocean meet - each perfectly adapted to this rapidly changing environment.

The National Wales:

Travelling across Wales, from Bae Ceredigion to Ynys Môn and the mouth of the Teifi to meet resident dolphins, cameras capture the drama of a guillemot pair trying to raise a chick; follow the exploits of an extraordinary rock pool fish and get up close and personal with seals and estuarine ducklings.

In never before seen footage, filmed in UHD (ultra-high definition), this first programme takes viewers into the glorious and vocal world of the playful and seductive bottle-nosed dolphins of Bae Ceredigion.

Filmed throughout an entire year, cameras witness what life is really like for Atlantic grey seals in Wales, from courtship to pregnancy and birth, including the trials and tribulations of an over curious snowy-white seal pup.

On the Teifi estuary, a family of Shelducks must stay clear of a fox on the hunt for ducklings.

In a rockpool in Abergwaun, as one of the largest tides of the year heads out, we join the antics of a little creature called a blenny.

Remarkably this home loving fish can survive out of water, but only for a while – will the tide return in time?

And in Gower, which has one of the largest tidal ranges in the world, oystercatchers show off their bill skills as they forage for seafood on the shoreline.

Music from Paul Mealor and performed by BBC National Orchestra & Chorus of Wales.

Wonders of the Celtic Deep begins on BBC One Wales at 9pm on Tuesday, October 12.