While scuba diving off the south-west coast of England this summer, I was lucky to encounter several different species of jellyfish in just a matter of weeks. Many of these, including the compass jellyfish (Chrysaora hysoscella), are already common to UK waters. But among them was one that I had never laid eyes on before – the crystal jelly (Aequorea victoria) – a creature capable of glowing in the dark.
The good news for fellow jellyfish enthusiasts is that both the abundance and diversity of jellyfish around the UK may be on the rise. Warmer sea temperatures mean that jellyfish can now inhabit a wider range of habitats, with some species moving polewards into waters that were once too cold for them.
Research carried out by the Marine Conservation Society (a UK conservation charity) suggests that there is a growing trend in sightings of certain species along the UK’s coastlines. Crystal jellies made up just 1% of UK jellyfish sightings in 2021. By 2022, this had risen to 3%.
