Winter Wild Swimming Guidance in Lochs and Rivers
For many of us, inland wild swimming doesn’t stop when the temperature drops—it simply changes. Winter swimming can be deeply
Ah, Scottish summer – the season of midges, bracing swims, and… jellyfish. Yes, it’s that time of year again when our coastal waters start hosting an elegant procession of jellies drifting in like graceful visitors from another world.
Let’s get this straight: jellyfish are both beautiful and mesmerising. Floating sea ghosts with a dash of danger. They are also, frankly, science fiction brought to life.
Jellyfish have been cruising the oceans for over 500 million years – long before the first dinosaur got to waggle their little t-rex arms. In fact, fossilised jellyfish impressions found in Utah in 2007 show that their design has barely changed in half a billion years. When you’re that successful, who needs upgrades?
They have no brain, no blood, and no heart, yet they’ve outlasted everything from trilobites to TikTok trends. They’re basically 95% water and 5% “don’t touch that, it might sting.”
Warmer seas – yes, that one week in July counts – are bringing an even wider array of jellyfish to Scottish shores. The Marine Conservation Society has been tracking increases in jellyfish sightings for the last two decades, with some exotic species (hello, Portuguese man o’ war) making cameo appearances. Scientists think climate change could be part of the reason, but more research is underway. In the meantime, the jellies are here, and they’re having a summer party.
Most of our native jellyfish species arrive in spring and summer to feed on plankton blooms, fish eggs, larvae, and sometimes, each other (yes, some jellies eat other jellies – nature is savage). When the timing’s right, jellyfish gather in large groups called blooms or smacks. This is peak jelly season – not only for spotting them, but also for a bit of jellyfish romance.
And how’s this for a love story: male jellyfish release sperm into the sea, which the nearby females then suck up through their mouths to fertilise in their stomachs. No dinner date required. They can also reproduce asexually which make s them incredibly adaptable. and a good reason why they have longevity.
Jelly Fish Doing their bit to Help the Planet
Yes, they drift, they sting, and they look like leftover pudding. But jellyfish are also quietly doing their bit to help the planet — playing an important role in the ocean’s natural carbon cycle.
When jellyfish die, many of them sink to the ocean floor, carrying with them all the carbon they’ve absorbed from the plankton and tiny creatures they’ve eaten. This process, known as the biological carbon pump, locks carbon away in the deep sea for centuries — like a natural underwater storage system for CO₂.
And it gets weirder (and cleverer). Some species of jellyfish secrete mucus (yes, really) that traps carbon-rich particles, forming sticky blobs that also sink. Scientists refer to this as part of the ocean’s “marine snow” — a slow-motion snowfall of organic material that keeps the carbon moving downwards, far from the atmosphere.
Add to that the fact that jellyfish provide food for deep-sea creatures when they die, and help keep plankton levels in check while alive, and you start to realise: these wobbly wonders are more than just summer tourists in Scottish waters. They’re ancient, essential, and weirdly wonderful climate allies.
Let’s take a closer look at some of the jellyfish you might encounter while dipping your toes or doing a brave breaststroke off the coast:
Blue jellyfish (Cyanea lamarckii if you want to sound clever) They can grow up to 30cm and give a sting no worse than a mild brush with nettles – annoying but not disastrous. If you’re in a regular swimsuit, it’s usually your arms and thighs that feel the tingle
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Moon jellyfish: These translucent beauties have a very gentle sting – most people don’t feel a thing. They’re round, dreamy, and probably the least threatening member of the jelly squad.
Lion’s Mane: Now this one means business. With long, trailing tentacles that look like Rapunzel’s hair underwater, the Lion’s Mane is a mix of grace and “ouch!” They’re reddish-brown and can give a powerful sting. What’s sneakier is that their tentacles often break off and float invisibly – until they find you.
Barrel jellyfish: Enormous but mostly harmless. With their mushroom-shaped bell and frilly underarms, they look like something out of a Miyazaki film. Often washed up on beaches in May and June like gentle sea aliens.
Compass jellyfish: Easily spotted thanks to the V-shaped brown markings on their bell – like nature’s own nautical design. But don’t be fooled by the beauty – they pack a painful sting. Fascinatingly, as they age, they switch from male to female. Nature’s multitaskers.
Portuguese Man o’ War (occasional visitor): Technically not a jellyfish but a siphonophore, which is like a jellyfish that outsourced all its body parts to a colony of specialists. They have long trailing tentacles and can sting even when washed up. Avoid.
We are visitors in their world. They’re ancient, mysterious, and entirely at the mercy of tides and winds. They float. They sting. They reproduce in ways that would make a romance novelist faint. And they do it all with absolutely no brain.
So next time you spot one pulsing gracefully past, take a moment to admire it – just preferably from a safe distance.
Being Cautious
When we go swimming or dipping we are in the world of the jelly fish – lets respect them and enjoy their company. We need to be mindful to keep our distance and be cautious of the really long and sometimes loose tentacles of the Lion’s Mane.
Wearing full body covering such as wetsuits or rash tops and leggings is a good way to protect yourselves from the stings.
What to do if You Do Get Stung
NHS has some great advise to follow
Jellyfish and other sea creature stings – NHS
DO
(I also find that antihistamine cream over the area helps once hot towel is removed)
DON’T
Go to A&E or call 999 if:
having any adverse or allergic reactions like:
For many of us, inland wild swimming doesn’t stop when the temperature drops—it simply changes. Winter swimming can be deeply
I reached out to the pals I swim with as the magic of water resonates with so many people and
I asked my swim buddy to share with me his experience of cold water dipping and what I received was