Posting on the Scottish Borders’ St Abb’s Head National Nature Reserve’s social media, its warden, Ciaran Hatsell, said he had counted 224 dead grey seal pups, with many more washing up.
Mr Hatsell said: “While the first concern is always human life, we then begin to worry about the effects of the storm on our wildlife.
“Having worked on seal colonies for 10 years I’ve never seen a storm cause damage on anything like this scale before.
Watch: Storm Arwen batters north coast of Scotland
“Unfortunately it appears we have lost the majority of our seal pups to this storm.
In a small area of bay at Pettico Wick there were 224 dead pups
National Trust for Scotland ranger Ciaran Hatsell
“In a small area of bay at Pettico Wick there were 224 dead pups in the water, with many more washing up ashore.
“We are planning to do another survey this week to see what the damage is to the rest of the colonies, but it doesn’t look good.
“This is a risk grey seals take with their breeding strategy, pupping at this time of year when storms are most frequent.
“But for this kind of phenomenal storm to hit at the peak of pupping is exceptional.
“On the reserve itself, there are lots of trees down at the Loch.”
“Thankfully no-one has been hurt but the lingering effects of the storm mean that the local community has been without power and this has been hampering our efforts to ensure the reserve is made safe.
“We’re expecting to have to use a lot of our charitable resources in clearing up fallen trees and other debris.
“As our ranger, Ciaran, noted in his social media post, the loss of seal pups to this brutal storm was substantial and certainly the worst that any of us have ever seen.
“We can’t be certain of the full extent of the loss until we’re in a position to conduct a survey later on in the week.
“Many National Trust for Scotland places up and down the east coast, Aberdeenshire and Moray, have been badly affected by the storms over the weekend, with damage to trees and buildings and many, like St Abb’s, remain without power.
“As a result, many properties are currently closed to the public, including wider estates, while our teams focus on making places safe and clearing up.
“We’d urge the public to please check before travelling to any sites for the next few days.”
Watch: Two killed during Storm Arwen as 100mph gusts cause major disruption