Jellyfish and poisonous algae could become more dangerous to beachgoers as sea temperatures climb, scientists have warned.
Some of the most intense marine heat increases on Earth have developed in seas around the UK and Ireland, the European Space Agency (Esa) has warned, which could lead to more risks for bathers.
Temperatures of 18C recorded in the North Sea are up to 6C warmer than is usual for this time of year.
