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Red beadlet anemone with opened tentacles

Bites and stings at sea

Find out how to treat bites and stings at the seaside – and how to avoid them in the first place.

From jellyfish and weever-fish to sharks and seals, you can find a whole new world of wildlife at the beach. But be careful – while most sea creatures are harmless, some can cause a painful injury with a bit or sting.

Jellyfish stings

Do jellyfish sting in the UK and Ireland?

Most jellyfish that live around the coast of the UK and Ireland are completely harmless. The stings from these species of jellyfish are mild and unlikely to cause pain – you might not even notice them:

  • moon jellyfish
  • barrel jellyfish
  • mauve stinger jellyfish
  • blue jellyfish.
A man is sat down with his foot in a bucket of water and is being helped by an RNLI lifeguard

RNLI/Nathan Williams

Always choose a lifeguarded beach – RNLI lifeguards are trained to treat bites and stings

Jellyfish

The most common species of jellyfish in the UK and Ireland is the moon jellyfish. You can recognise them by the four circles that are visible inside the centre of the creature. The biggest jellyfish species you’ll find is the barrel jellyfish – they can grow up to 1 metre in width.

While most are harmless, there are some species of jellyfish found in UK and Irish waters that cause painful stings:

  • compass jellyfish
  • lion’s mane jellyfish
  • Portuguese man o’war.

These species can leave a very nasty sting if you come into contact with them, so be very careful. A sting from a Portuguese man o’war can leave you in pain for several hours. It isn’t native to the UK and Ireland, but it sometimes finds its way here. It’s also not technically a jellyfish, but is often labelled as such.

A compass jellyfish is in the sea, its tentacles visible

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Be careful – a compass jellyfish sting can be very painful

How to treat a jellyfish sting

RNLI lifeguards are trained to deal with jellyfish stings. So, if you’re visiting the coast for a swim, make sure you visit a lifeguarded beach. If you do get stung, this is the jellyfish sting treatment the lifeguards will provide:

  • Scrape off any remaining tentacles: Make sure any tentacles still attached to your body are removed. But be careful not to rub them into the skin, as this will cause more damage and pain.
  • Rinse with cold sea water: This should help alleviate the pain. Do not urinate on the sting. This is not effective and only works in films and TV shows!
  • Avoid applying fresh water or cold packs: This will not do anything to help and could make it more painful.
  • Immerse injured limb in very warm water for at least 30 minutes: Keep the injury in the water until the pain becomes bearable.

Once you’ve had your sting treated, you might be asked to wait for half an hour to ensure you don’t have an allergic reaction to the sting. 

If you aren’t at a lifeguarded beach and have a severe or life-threatening reaction to a jellyfish sting, you should call 999 or 112 and ask for an ambulance.

What to do if you see a jellyfish

At certain times of year, jellyfish blooms come close to shore. Try to avoid them, but if you know you’ll be in the sea with jellyfish, minimise the amount of exposed skin to reduce your chance of stings. Wetsuits offer good protection and rash vests will shield you from most jellyfish tentacles.

Sometimes jellyfish get washed up on the beach. If you see a jellyfish on the beach, don’t touch it. You can still get stung when handling them – even if you’re certain they’re dead.

Instead, if you’re at a lifeguarded beach, report the jellyfish to a lifeguard. You can also report your sighting to the Marine Conservation Society (UK) or the National Biodiversity Data Centre (Ireland).

Weever-fish

What is a weever-fish?

Weever-fish are plain-looking but venomous fish that spend a lot of time buried in the sand in very shallow water, lying in wait for their prey.

To defend themselves, weever-fish leave their dorsal fin exposed, pointing upwards. The dorsal fin contains three spines containing a venom. This protects them from potential threats. Unfortunately, that threat is often the foot of someone going for a paddle along the shoreline.

Wearing water shoes when you’re paddling at the beach will help you avoid getting stung.

A weever-fish is half-buried in the sand, with just its head visible

Simon Rogerson

Weever-fish sting in self-defence if they are trodden on

How to treat a weever-fish sting

The amount of pain a weever-fish sting causes depends on the number of spines that have punctured the skin and the pain tolerance of the person who has been stung.

All RNLI lifeguards are trained to treat weever-fish stings – just another reason to always visit a lifeguarded beach. This is the treatment they will provide:

  • Rinse with cold sea water: This should help alleviate the pain.
  • Immerse injured limb in very warm water for at least 30 minutes: Keep the injury in the water until the pain becomes bearable.
  • Check and care for the puncture wound: You may need to bandage the area.

If you aren’t at a lifeguarded beach and have a severe or life-threatening reaction to a weever-fish sting, you should call 999 or 112 and ask for an ambulance.

Sharks

Do sharks bite in the UK and Ireland?

While sharks have a bad reputation, shark bites in the UK and Ireland are incredibly rare. According to the Shark Trust, there are no records of unprovoked shark bites in British waters since 1847, when records began. In fact, it’s rare to even see a shark here – overfishing and demonisation of sharks has led to many species becoming threatened or endangered.

A nursehound shark is on the seabed amongst coral, rocks and seaweed

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Nursehound sharks are one of the species of catshark found in the UK and Ireland

What species of shark are found in the UK and Ireland?

There are many species of shark native to the UK and Ireland. These include several types of dogfish and catshark species. You can often find their eggcases washed up on the beach. 

Blue sharks are one of the more common predatory sharks in our waters, but they spend most of their time out in the Atlantic Ocean so are rarely seen.

Basking sharks are one of the largest species of sharks on the planet. Despite their size, they are completely harmless to humans. They feed on plankton by filtering sea water through their huge gaping maws.

What to do if you see a shark

It’s very unlikely that you will come face to face with a shark. But to keep yourself safe, you should:

  • always swim at a lifeguard-patrolled beach and between the red and yellow flags
  • leave the water immediately if a shark is sighted.

If you do see a shark, you can also report your sighting to the Shark Trust. Your sighting will help them collect important data for shark researchers and conservationists.

Seals

Do seals bite?

The two most common species of seal in the UK and Ireland are the common seal and the grey seal. While they look cuddly and friendly, they are wild animals and can give a nasty bite if they feel threatened. Seal bites are very serious, so if you spot one lounging on land or swimming in the water, be sure to keep your distance.

 

A grey seal is resting on the seabed amongst green seaweed

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Grey seals are beautiful, but keep your distance

What to do if you see a seal

If you see a seal in the wild, always keep a safe distance away from it – ideally far enough away that it cannot see, hear or smell you. This will help you stay safe, but it will also avoid making the seal stressed. There’s a risk that it could injure itself or other seals if it panics. If you have a dog, always keep it on a lead around seals. Never feed seals – it is dangerous for both them and us.

Other sea creatures you may encounter

Sea urchins

Sea urchins are round, small and spiny. They are often found on rocks in shallow water, so it’s easy to accidentally come into contact with them when you’re at the coast. Be careful – a sea urchin sting can be very painful. 

Sea anemones

A close relative of corals, you can find sea anemones stuck on rocks. These are colourful, soft-bodied creatures that can produce a nasty rash if brushed against – though most people won’t be affected by them.

Crabs

Crabbing is a great activity to do at the beach, but stay clear of their pincers. Always handle crabs carefully and gently. The best way to hold a crab is to put a finger on one side of the shell and a thumb on the other side. Make sure your fingers are just behind its pincer legs.

A spiky purple sea urchin on a reef

Credit: Shutterstock/NatalieJean

Sea urchins can be found on rocks but be careful - their sting can be very painful