Conservationists have warned it rare seabird colonies on one of Scotland’s furthest-flung outposts are at risk of “disappearing forever” in the face of climate change.  

A first-of-its kind study carried out by the National Trust for Scotland (NTS) found that flocks living on the abandoned islands of St Kilda face an uncertain future as the planet warms. 

Increased storm activity will damage vital breeding grounds and make it difficult for staff to access the islands, while warming seas mean the food chain is being disrupted.  

NTS said that it would become “increasingly difficult” to protect the colonies in the years to come, including those of an estimated 1 million sea birds such as Puffin, Fulmar, Gannet, Kittiwake and Shags.  

The last remain people living on St Kilda were evacuated in 1930 and the three islands which make up the archipelago - Soay, Hirta and Dun – have returned to nature.  

Today, the islands are managed by the NTS, Scottish Natural Heritage and the Ministry of Defence.  They are the only place recognised in the UL as dual World Heritage Sites for their historic and natural significance. 

The Herald: The islands boast rugged scenery The islands boast rugged scenery (Image: NTS)

The latest warning about the effect climate change is having on the islands’ natural balance comes after a Climate Vulnerability Index (CVI) probe was carried out.  

CVI studies assess the predicted changes to climate in World Heritage Sites, and the potential impact on these places. 

This is the first time the method has been applied to a place designated for both its natural and cultural significance. 

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National Trust for Scotland Property Manager for St Kilda Susan Bain said: “Taking care of St Kilda is a huge task for the National Trust for Scotland.

“We have certainly been experiencing the effects of climate change on St Kilda for decades, with the impacts on some of the seabird species and marine habitats being particularly profound. 

“This report tells us that in the future we will have more and more challenges to manage, and it will be increasingly difficult to do so.” 

She added: “Warming sea temperatures are already impacting on the food chain for the hundreds of thousands of seabirds who breed here each summer, and some species are at risk of disappearing from St Kilda forever.

“Changing currents could compound this even further, fundamentally changing the habitats and with that the types of birds that can thrive here. 

“St Kilda is a special place, and the National Trust for Scotland is privileged to care for its nature, beauty and heritage for everyone. The scale of this task is only going to grow, and our charity will need more and more support to carry out our work in the future.”

The Herald: 1 million seabirds are estimated to live on the archipelago1 million seabirds are estimated to live on the archipelago (Image: NTS)

Last year, NTS counted populations of four species of cliff-nesting seabird on St Kilda, and found that, compared with the previous count in 1999, cliff-nesting seabird numbers had declined by more than half (61%), while fulmars in particular had declined by 70%.

St Kilda represents the fourth CVI application conducted in Scotland’s World Heritage through a partnership between Historic Environment Scotland and James Cook University in Australia.

Systematic assessments of climate vulnerability have been undertaken for neolithic heritage sites in Orkney, the historic city of Edinburgh, and the Antonine Wall.

A variation of the CVI was also applied for the Flow Country, currently being considered for World Heritage status. 

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Dr Mairi Davies, Climate Change Policy Manager at Historic Environment Scotland, said: “The results align with what we are seeing across Scottish heritage properties, which is that climate change and extreme weather are speeding up the deterioration of natural and cultural heritage. 

“We believe that the historic environment sector, with organisations such as the National Trust for Scotland and tools such as the CVI, has a crucial role to play in the development of a climate ready Scotland.  

“It is becoming increasingly clear that action must be taken on every level, and research projects such as the one conducted on St Kilda give us a clearer picture of what is needed to address loss and damage and adapt to the changing climate.” 

The Herald: The last islanders left in 1930The last islanders left in 1930 (Image: NTS)

St Kilda represents the fourth CVI application conducted in Scotland’s World Heritage through a partnership between Historic Environment Scotland and James Cook University (Australia).  

Systematic assessments of climate vulnerability have also been undertaken for neolithic heritage in Orkney, the historic city of Edinburgh, and the Antonine Wall. 

CVI co-developer, Professor Scott Heron said: “The CVI assessments of Scottish World Heritage, undertaken to-date, have indicated moderate to the highest levels of vulnerability to climate threats including from changes in precipitation and temperature.  These represent substantial risks from future climate change to the heritage values in each site. 

  “The analyses also indicate that there are likely to also be impacts on communities from the climate change-driven decline in World Heritage values.”