Fersiwn Gymraeg ar gael yma

The Celtic Sea is one of the UK’s most important areas for seabirds. Breeding, wintering or migrating, they utilise this sea area in their millions. However, it is fast becoming a hotspot for the next phase of offshore wind generation in the battle against climate change. On World Ocean day, Greg Morgan, RSPB Ramsey and Grassholm island Site Manager, looks at what potential conflicts with seabirds could this bring.

The Celtic Sea (Y Môr Celtaidd) is the area of the Atlantic Ocean lying to the west of Wales and south of Ireland, bounded to the east by St George’s Channel and the Bristol Channel and further south the Bay of Biscay.

The UK is globally important for seabirds and the Celtic Sea supports over 50% of the entire world population of Manx shearwaters with the vast majority of those on the Wildlife Trust of South and West Wales islands of Skomer (350,000 pairs) and Skokholm (90,000 pairs), with a small but ever increasing population on RSPB Ramsey Island (5,000 pairs). Add in non breeders and you have over a million Manx shearwaters that call the Celtic Sea home. Despite this, many people may never have seen a Manx shearwater. They are nocturnal on land, spending the day at sea before returning to their breeding colony burrow nest sites under the cover of darkness.


Manx shearwater at breeding colony on Skomer Island (photo: D Boyle)

Head further west and RSPB Grassholm supports around 10% of the world population of northern gannets with 36,000 pairs. Add in the Pembrokeshire islands supporting large breeding populations of puffin, guillemot, razorbill, storm petrel, kittiwake, fulmar, shag, herring, lesser and great black backed gull  and you get a feel for just how vital this sea area is.


RSPB Grassholm from the air (photo: RSPB)

But that’s only half the story. The breeding seabirds are perhaps more obvious, most visible to the thousands of visitors who flock to Pembrokeshire to enjoy the annual spectacle and are so vital to the local economy. But the Celtic Sea is arguably as busy during the winter months too when tens of thousands of seabirds descend on this rich and prosperous marine environment.

Kittiwakes and gannets from colonies further north in the UK and Scandanavia forage far and wide around the Celtic Sea all winter. They are replenishing body condition after a taxing breeding season before heading north again in the spring. Guillemots and razorbills don’t go far from their breeding sites, the former often returning to occupy cliff ledges on calm winter mornings, defending their precious territories even during the depths of a Pembrokeshire winter.


Common guillemots on breeding ledges on RSPB Ramsey Island (photo: RSPB)

Fulmars are never far from their summer breeding grounds either. After a brief spell out at sea to moult in autumn, they return and are present on and off all winter making them the UK  seabird that spends the most time at its breeding site (good quiz question that!)

And it’s not only breeding and overwintering birds that make the Celtic Sea so important. Countless numbers of seabirds use it as a migration flyway; linking far flung northern climes with southern hemisphere hotspots. Skuas and terns, petrels and gulls all move in their tens of thousands through this narrrow stretch of water in spring and autumn. Closer to home, internationally important numbers of common scoter winter in Carmarthen Bay, most of which will have made the journey south from their northern breeding grounds via the Celtic Sea.

Major changes in store for the Celtic Sea

On 24th March The Crown Estate (TCE) issued a press release announcing the progression of plans to deploy new floating wind technology in these waters.  

The role of offshore wind in decarbonising our energy systems is undeniable, however the current approach places both net zero and nature in jeopardy. Read more about that here. Floating wind technology has the potential to reduce the conflict between turbines and wildlife, for example by allowing deployment in deeper waters further from our seabird breeding colonies. However, RSPB research has shown how wide-ranging breeding seabirds can be and as we have just set out, these waters are important for seabirds all year round.  

To ensure that floating wind becomes part of the solution and not more of the problem, we need to ensure the right technologies in the right place, with enough space for nature. This is one of the reasons the RSPB strongly supports the Offshore Wind Evidence and Change programme, a new initiative being led by The Crown Estate, Defra and BEIS to ensure the sustainable expansion of offshore wind. By working closely with Governments, industry and other NGOs, we aim to find joint solutions for climate and nature that will allow us to meet net zero targets and revive our seas. We believe that for offshore wind deployment to deliver for people, nature and climate, holistic marine plans are urgently needed to consider all uses of our seas and  the best available evidence to identify the least ecologically sensitive areas for renewable technology.

We strongly welcome The Crown Estate commitment to help develop floating wind in a way which is “sensitive to our precious marine habitats” and we encourage them to put the protection of marine wildlife at the heart of their approach to developing floating wind in the Celtic Sea. We look forward to working with them and others to ensure these  internationally important waters remain at the forefront of seabird conservation.

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