It’s no secret that global temperatures are rising, and water levels along with them. A study has even revealed what the UK would look like if all the ice on Earth’s surface melted. We’re a while off that yet, but the oceans are definitely getting warmer and this is changing the ecosystem that exists below the surface.
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The Marine Conservation Society has recently carried out a survey that shows a significant increase of a certain type of animal in UK waters: the jellyfish. With Storm Ciaràn creating chaos in the UK, summer seems like a distant memory - but we did see some intense heat waves. Well, a marine heatwave in June increased the water temperatures by around 3-4C. With these rising temperatures, the number of jellyfish in UK waters and on beaches has shot up by 32%. Let’s have a look at the types of jellyfish spotted, what to do if you see them, and what this could mean for our planet.
The types of jellyfish spotted
The most commonly spotted were the huge barrel jellyfish. Luckily, though these jellyfish will sting you, the effects of their sting are very mild. According to The Wildlife Trusts:
The sting of the barrel jellyfish is not normally harmful to humans, though if you find one on the beach it's best not to handle it as they can still sting when dead.
These animals, known commonly as ‘dustbin-lid jellyfish’, can grow up to 3ft in diameter.
Warm-water crystal jellyfish were also spotted, which once again do sting, but are not strong enough to harm humans. Matt Slater of Cornwall Wildlife Trust told BBC Radio Cornwall:
I was actually diving last week off the Lizard and there was a huge number of them and they were accumulating in the bays and forming almost a ceiling above us as we were diving underwater.
What this means for our planet
The BBC have reported on this phenomenon, explaining that these increased numbers could mark a more serious issue. Peter Richardson, Head of Ocean Recovery at the Marine Conservation Society, said:
These numbers could be part of a 20-year long boom-and-bust cycle but there are very few surveys out there which show what's happening.
But this survey gives us an indication of what's happening in our seas with climate change.
Dr Abigail McQuatters-Gollop, a plankton expert at the University of Plymouth, said this phenomenal ‘could be an indication that as climate change is happening, we are seeing tropicalisation of the oceans’:
But we don't know if the high numbers this summer are a longer-term natural trend or linked to the marine heatwaves. There is a lack of research - we have to do more studies.
For now, experts seem to need more information before drawing any solid conclusions. However, looking forward, warmer UK waters may mean further changes to the ecosystem. Indeed, the Marine Conservation Society have also reported 12 turtle sightings: ‘four of these were of the leatherback, the largest sea turtle’.
BBC: Boom in unusual jellyfish spotted in UK waters
The Wildlife Trusts: Barrel jellyfish
Independent: Rare crystal jellyfish identified off Cornwall coast