Marine heatwaves to become more frequent off UK and Irish coasts, experts say

Phytoplankton blooms in the Celtic Sea. The full disruption to the marine ecosystem caused by the 2023 heatwave has not been assessed, but scientists know it has significantly disrupted phytoplankton blooms. Photograph: ZUMA Press, Inc./Alamy

The unprecedented marine heatwave of 2023 was in line with climate modelling, research shows, as scientists warn such events will become more frequent.

The “unheard of” heatwave off the UK and Irish coasts during a summer of 40C temperatures raised concerns that fish, shellfish and kelp would not be able to survive.