Marine Stings – How To Handle Them

stings stabs
Photo Credit – Capt. Scott Goodwin

Although the focus of this will be on Marine envenomation from corals, sea urchins, fish, stingrays, and jellyfish I figure I would start off with a personal story with a sting from a scorpion.

Our close family friends had a house on the beach in San Francisquito, Baja California. This is a remote destination about 85-miles south of Bahia de Los Angeles. Every year my dad would fly my mom, sister, and myself down for a month of fishing and diving. Needless to say this was absolutely incredible. One day (I think I was probably 14 years old) we took the panga out for a diving/snorkel trip.

Rule #1 is to check your booties before putting them on and jumping in to make sure there aren’t any scorpions in them. Well needless to say I skipped that step and on they went. Lasting only about 15 seconds in the water I had sharp pain in my right foot.

Reflexively I pulled the bootie off to see a scorpion float away.

I remember getting into the boat and having sharp pain in my foot and feeling soreness in my inner thigh (from venom traveling up my lymphatic system).

So now what? Not sure if any of you have heard people say “Urine Kills the Toxins.” Something I will never forget. My mom, her friend, and 3 kids all pee’d in a bag. They had me put my foot in the bag and off to diving they all went.

Was this necessary? Well short answer is probably not but if you keep reading you will see our data on how to treat stings isn’t based on powerful scientific studies.

Ok so here we go.

Whenever you encounter a marine envenomation you should ask yourself how serious is it?

The most important take home is to determine is there is a local or systemic response to the sting or stab.

Local Response

Is an isolated reaction to the negative stimulus. This means if you scrape against coral on your right arm and it becomes painful at the site where you rubbed against the coral, you are having a localized response.

Systemic Response

Is there a multi-system response that spreads beyond the site of the negative stimulus. If you get a jellyfish sting to the right leg but start to develop confusion or swelling of your face or shortness of breath you are having a systemic response and this is more serious. Even if it just starts with confusion this should be concerning that you may soon develop worse symptoms.  You need to get immediate medical attention in this case.


fire coral

Coral stings and lacerations usually cause mild pain and redness.

marine stings

Mechanism: A sting is caused by venomous capsules called nematocysts, just like jellyfish.

jellyfish sting

At a microscopic level this is what is happening. These specialized cells basically have a harpoon that shoots into your skin (epidermis and dermis), which gives the cell access to release its toxins.

Fact: When triggered (usually mechanically by rubbing against it) the creature shoots its harpoon mechanism with an acceleration at 40,000 g’s (times gravity). For perspective purposes a fighter pilot usually passes out at 9 g’s.

So with coral there are two aspects to consider when thinking about treatment: Stings and Scrapes.


  • Its possible you could still have nematocysts on your skin that have not fired off their harpoons. Thus a good spray of saltwater to the area could knock some of them off.
  • Don’t use freshwater as the salt concentration (osmotic load) is different from these cells and it may cause them to fire away, making the pain worse.
  • Hot water immersion for 90 minutes (40-45 degrees Celsius-hottest water without causing a burn or Vinegar to try and destroy the venom (proteins) causing the pain. There is some limited data here to suggest hot water is best.

Fact: Venom (usually proteins) is the inflicting agent causing pain due to binding to our receptors and causing an immunological response. Hot water or vinegar can “denature” or destroy the protein (change the shape) so that they do not have the ability to act on our receptors to cause the immune response, thus lessening the signaling, and ultimately resulting in less pain.


  • Wash the area very well with soap and water and make sure there isn’t any foreign material left inside the skin
  • Monitor this area for secondary infections: look for worsening redness around skin in the next couple days (cellulitis)
  • Apply Bacitracin or Polysporin to this area
  • Keep out of the sun while the skin heals to avoid a bad scar


jellyfish sting
Man O War jellyfish stings that caused systemic reactions. Photo Credit – Capt. Scott Goodwin

Jellyfish do not have puncture wounds. After a jellyfish sting, linear red, urticarial lesions typically develop a few minutes later, although sometimes these lesions do not appear for several hours.

We wont get into it to much here. But within the jellyfish family, you should know there are a species called box jellyfish which have venom that is much more potent than most. Due to the higher than normal chance of getting systemic symptoms with stings from these species you should go to the Emergency Room for evaluation.

Photo Credit –

Trivia: Irukandji syndrome is a condition induced by venomization by the sting of Carukia barnesi, a species of Irukandji jellyfish, and certain other box jellyfish. Unless immediate medical action is taken, victims can go into cardiac arrest and die. The syndrome was given its name in 1952 by Hugo Flecker, after the Aboriginal Irukandji people who live in Palm Cove, north of Cairns, Queensland, Australia, where stings are common.

Jellyfish have the same mechanism as described above but they have tons of nematocysts on each tentacle.

sting treatment
Lakkis NA, Maalouf GJ, Mahmassani DM. Jellyfish Stings: A Practical Approach. Wilderness Environ Med. 2015;26(3):422-9.

This is where it gets interesting. If you look up the literature you will find all kinds of interesting treatment including: Hot Water Immersion, Vinegar, Alcohol, Urine, Meat Tenderizer, baking soda paste, and cold packs.

The majority of the studies found discuss Hot Water Immersion, vinegar, and cold packs. You can almost find a study out there that will say one is better than the other for each choice. Interesting that either cold or hot can work?

However I’d say Hot Water Immersion and vinegar are the go to treatments. As you will see below even depending on what type of jellyfish one of these choices may be better since vinegar could otherwise make it worse (make nematocyst deploy their harpoons).

sting treatment
Berling I, Isbister G. Marine envenomations. Aust Fam Physician. 2015;44(1-2):28-32.

Sea Urchin

urchin spines

There are over 600 unique species of sea urchin of which, only 80 have venom delivery mechanisms.

Thus the majority of sea urchins are not poisonous but cause pain from the penetration of their spines (made of calcium carbonate).

urchin treatment


  • Remove the spines
  • Clean area with soap and water
  • Obtain an x-ray if there is any question of spines still in the skin. X-ray can still miss retained spines. MRI would be best but given cost and availability it’s not routinely done.
  • If it’s a venomous sea urchin then hot water immersion as above

Venomous fish

lionfish injury
Photo Credit – Capt. Scott Goodwin

The geographic distributions for the most common venomous fish include:

Catfish – These bottom dwelling scavengers are found in fresh water rivers worldwide. The marine catfish resides in many regions as well.

Stonefish –Are primarily found in the coastal waters of the Indo Pacific region including Australia, Indonesia, and India.

Scorpion and lionfish –Reside widely in tropical and temperate oceans. They are frequently kept as pets in home aquariums.

Weeverfish –Inhabit the shallow waters of the Atlantic Ocean and Mediterranean Sea

The venom apparatus is similar for fish worldwide.

Spines cover integumentary sheaths, which contain venom glands. When the spine penetrates the victim’s skin, the surrounding integument covering the spine ruptures and venom is injected into the wound.

poisonous fish


  • Remove any retained spines
  • Hot Water Immersion as stated above
  • Clean with soap and water
  • Monitor for secondary infections
  • Stonefish; there is an antivenom available if the pain is not relieved with Hot Water Immersion.


stingray injury
Photo Credit – Capt. Scott Goodwin

There are 150-species of stingrays worldwide, accounting for thousands of injuries every year.

stingray treatment
Photo Credit – Capt. Scott Goodwin

The stingray uses its whip like tail with a furrowed, serrated spine containing secretory venom cells and sacs. When the animal is stimulated or frightened, it flings the barbed tail upward, embedding the spine in the victim, which releases the venom. The resulting wound is a combination of a puncture and jagged laceration, usually of a limb.

stingray treatment

Everyone may remember Steve Irwin who encountered a large stingray that freakishly gave him a penetrating barb injury to his heart resulting in death. This is very rare but just highlights the respect you must have for marine creatures.


  • Remove any retained spines. Caveat is if there is deep penetrating injury to neck, chest, or possibly near blood vessels then leave in place until it can be removed in the safest place (Operating Room).
  • Hot Water Immersion as states above
  • Clean with soap and water
  • Monitor for secondary infections
first aid


  • Wounds caused by corals, jellyfish, sea urchins, spiny fish, and stingrays are common occurrences around the world during water-based activities.
  • Marine envenomation is characterized by pain, which can be severe, and puncture wounds to the affected area. The degree of pain is largely determined by amount of venom injected and potency of venom.
  • After a marine envenomation, one should either treat with Hot Water Immersion for 90 minutes (40-45 degrees Celsius) or vinegar for some jellyfish species as seen above.
  • Wound care including salt-water irrigation, removal of foreign bodies, and tetanus prophylaxis should be considered. Any deep penetrating wounds should be taken to the Emergency Room for further evaluation.
  • If there are any signs of systemic reactions, one should seek immediate medical attention.
Dr. Brad Genovese
Brad Genovese. I was born and raised in Laguna Niguel, California. He has been greatly blessed to have incredible parents that introduced him to sport fishing, hunting, and travel at an early age. Growing up he spent many summers fishing and diving the Sea of Cortez. Brad says, “Although my entire...