Rising sea temperatures could threaten the future of the popular kittiwake colony at Splash Point in Seaford, according to the RSPB.
There is evidence of a link between rising sea temperatures and a reduction in the numbers of the birds’ main food source, sand eels.
If the colony cannot adapt to find another supply of food it will struggle to survive, the conservation charity warned.
In other parts of the country the impact of rising sea temperatures is already being felt.
Seabird declines are particularly serious in the Northern Isles of Scotland and some colonies in the South East have also been badly affected.
In the early 1990s there was a colony of almost 3,000 pairs of kittiwakes at Langdon Cliffs near Dover in Kent, but this colony has declined alarmingly and in the last few years only a few tens of nests have been recorded.
In Sussex the number of breeding birds has not declined in the same way as in Northern Britain, with the main colony at Seaford still containing over 1,000 nests.
Why this colony has fared better is not yet understood - it could be that sand eels are doing better in the South East, or the birds may be feeding on alternative prey, as they do off the coast of Ireland.
However the South Coast is predicted to have the biggest rise in sea temperatures in the UK, perhaps as much as 3.5 degrees by the end of the century.
A spokesperson for the RSPB said: “The effects this will have on the marine ecosystem are very hard to predict.
“UK conservationists are working hard to create new heathland habitat for them to move into. To give our marine eco-systems the best chance to adapt to changes like these, we need to maximize their resilience by minimising pressures from other sources.
“That’s why it is so important they are protected from dredging and over-fishing.”
As the report from the Intergovernmental Panel on Climate Change (IPCC) is released, the RSPB said kittiwakes in Scotland faced extinction from areas that were once strongholds.
Head of habitats and species for RSPB Scotland, Paul Walton said: “Ten years ago Marwick Head on Orkney was a thriving seabird city – but now it looks like a ghost town.
“And it’s not just kittiwakes, guillemots have also halved in number. A few abandoned nests remain in the breeding season on some cliffs, which are silent and empty, instead of alive with noise and activity as they were a few years ago.
“Seven colonies across the islands are essentially lost, and another two are heading down the same road. Evidence points to rising sea surface temperatures driving huge declines and species shifts in plankton populations.
“This is the food of sand eels, and the sand eels are food for the birds. We are calling on the Scottish Government to designate key seabird feeding sites as Marine Protected Areas to offer seabirds and sand eels resilience against the effects of climate change. However, a much bigger challenge is to convince world leaders to heed the warnings in the IPCC report, and do much more to tackle climate change.”