An epic spectacle, described as the sea 'boiling' has been recorded by the island's Wildlife Trust.
An Alderney Wildlife Trust drone took flight on 8 September, after the team spotted commotion off the north coast.
Flying 50 metres above the surface, the drone's camera captured the rarely witnessed "boiling sea" effect.
It is caused by large numbers of Atlantic bluefin tuna hunting in a pack.
They round up prey into large shoals, known as bait balls, and then charge into them, causing a white circle of breaking waves that resembles boiling water.
Footage shows local seabirds taking advantage of the collection of small fish and swooping down to feed.
The Alderney Wildlife Trust's ecologist Alex Purdie says the sighting shows conservation efforts are working.
"Around the 90s, bluefin tuna were pretty much locally extinct.
"There might be the odd one, but we really didn’t see them in numbers, and that’s largely due to over fishing.
"But there was an international action plan to protect the stock, and thanks to that we are starting to see them coming back in."
The Trust believes that the drone footage is the only overhead video of bluefin tuna hunting ever captured in Channel Island waters.
Alex says it is incredible.
"It shows that the kind of power and diversity of nature here can be as amazing as the lions on the Serengeti or from the fjords in Norway."
Guernsey cyclist becomes MBE in King's Birthday Honours
Guernsey students heading to university to receive Meningitis B vaccine
Guernsey teen set for month-long marathon swim
Guernsey Post introduces new services from early July
Guernsey Waste improves the quality of its free garden compost
Guernsey cat lover to ride the length of Britain in nine days
Unclaimed CI Co-op cash funds community projects
Work to commence on 70 affordable flats and homes in Guernsey
