News · 20 July 2026
Guernsey's 17.7C waters bring new species, threaten others
Photo by Maël BALLAND on Pexels
A marine heatwave has caused a shift in Guernsey's sealife, with some species becoming more common. Sea Fisheries reported the island's water temperature in early July was 17.7C, which is 2.7C higher than the average for that week between 1980 and 2019. The heatwave has led to more octopus and Mediterranean comber fish, but also concerns for colder-water crustaceans.
Reported by BBC · How we write briefs