The Guardian reports busy beaches and warm, calm seas fuel sightings of lion’s manes, compasses and moons. From a “mile-long” swarm in Devon to warnings to swimmers in the Outer Hebrides, it seems jellyfish are difficult to ignore this summer.

High temperatures, calm and warm seas and packed beaches have resulted in large numbers of reports of jellyfish blooms around the UK coast, and combined with a glut of the plankton on which they feed, some are reaching record sizes, experts said. At the fishing town of Brixham, Devon, one kayaker and photographer witnessed what he described as a mile-long mass of compass jellyfish. They have also been spotted in large numbers along the Cornish coast.