Sea urchins in Sri Lanka, how to avoid them and what to do

Sea urchins live among rocks and reef, so you avoid them by walking into the water where the sand is clear and keeping your feet up near rocks. If you step on one, medical sources say to soak the foot in hot water, take out the spines you can reach with tweezers, keep the wound clean and open, and see a doctor.

This page is general information from the sources named below. It is not medical advice.

Where do sea urchins live, and are they dangerous?

A sea urchin is a round animal covered in spines, a relative of the starfish. It sits in cracks in rock, on reef and in rock pools, and eats what grows there. Many tropical kinds are dark, with long, thin spines.

An urchin does not attack and does not come towards you. Every injury is the same story: a foot, a hand or a knee is put down on one. The spines are sharp, hollow and brittle. They go in easily, through thin water shoes and wetsuits too, and they break off in the skin.

The result is painful more than it is dangerous. Divers Alert Network, a medical organisation for divers, writes that immediate threats to life from urchins are very rare. The trouble comes later, when a spine is left near a joint or a wound gets infected.

How do you avoid them?

• Walk in where the sand is clear. Look before you step. Urchins live in rock, not in open sand.
• Near rocks and reef, float. Once the bottom turns dark, lift your feet and swim. Do not put a hand on a rock to steady yourself.
• Shuffle your feet when you wade in water you cannot see through.
• Wear water shoes on rocky ground. The NHS in Britain advises waterproof shoes or sandals in shallow or rocky water. They help against a light touch. They do not make it fine to walk on rocks, because a long spine goes through a thin sole.
• Keep out of rock pools at low tide, however pretty they are.
• Do not pick urchins up.
• Tell children before they go in, not after.

At Ohana, sea urchins live in the rocks around the bay. The sand in front of us is the way in. If you are not sure where that is, ask us and we will show you.

What should you do if you step on one?

Get out of the water, sit down, and look. Then, following the NHS, Divers Alert Network and the MSD Manual:

• Soak it in hot water. As hot as you can bear without burning, for at least 30 minutes. Divers Alert Network gives a limit of 45°C and up to 90 minutes. Somebody who is not hurt should test the water first, because pain makes it hard to judge heat. Heat is what eases the pain.
• Take out the spines you can reach. Use tweezers. Pull straight, and do not squeeze from the sides, because the spines are fragile and snap. Leave the deep ones for a doctor. Digging makes things worse.
• Wash the wound gently. No hard rubbing while spines may still be inside.
• Put on an antiseptic if you have one.
• Leave the wound open. Do not close it with tape or glue.
• Take a painkiller you normally use, such as paracetamol or ibuprofen, if you need one.

What about vinegar? The MSD Manual says vinegar dissolves most spines that are near the surface, and that a few soaks or wet compresses may be enough. Divers Alert Network's first aid steps do not include it. The sources do not agree, so do not let vinegar take the place of the hot water or the doctor.

If the place still hurts when you press on it after a day or two, a piece of spine may still be inside. That is one more reason to see a doctor.

What should you not do?

The NHS list is short and clear:

• Do not urinate on it. It does not help.
• Do not put ice or a cold pack on it.
• Do not touch spines with bare hands.
• Do not cover or close the wound.

When should you see a doctor?

Sooner than you may think. Divers Alert Network advises a medical check as soon as reasonably possible, even after good first aid. The NHS tells its readers to go to a minor injuries unit for any sea creature sting that happened in a tropical country. Sri Lanka is one.

Go without waiting if:

• a spine is in or near a joint, such as a toe joint, the ankle, a knuckle or the knee, or moving the joint hurts badly
• spines are deep and you cannot get them out
• the pain is severe and does not ease with heat
• the wound becomes more red, more swollen or warm over the next days, or you get a fever
• you are not sure your tetanus vaccination is up to date

Call for emergency help at once for difficulty breathing, chest pain, a fit, severe swelling, vomiting, or feeling faint. These are rare, but they are the signs every one of these sources lists.

You can read the sources yourself: the NHS page on sea creature stings, Divers Alert Network on sea urchins and the MSD Manual on sea urchin stings.

If it happens at Ohana, tell us straight away. We keep a first-aid kit with tweezers and disinfectant, and we have hot water for the soak. There is a hospital about five minutes away by road.

Should urchins keep you out of the water?

No. They are part of a living reef, like the turtles that feed on ours. They ask one thing: that you look where you put your feet. For the rest of the manners in the water, see how to snorkel with turtles respectfully and our list of places for snorkeling near Hiriketiya and Dikwella. There is more about the bay on our page about Turtle Beach and swimming with its turtles.

Good to know

• Sea urchins live in the rocks of our bay. Walk in where the sand is clear.
• Ohana is at Turtle Beach, Dikwella, less than five minutes by road from Hiriketiya.
• Snorkel masks are lent free. Ask at the bar.
• We keep a first-aid kit with tweezers and disinfectant, and hot water for the soak. Tell us straight away.
• We are open every day from 08:00 to 21:00.