As summer approaches and our waters begin to warm to the point where even the wimpiest of dive masters is prepared to relinquish their wet suits, one of the down-sides is the arrival of jellyfish season. Here’s a primer on Jellyfish identification, stings and related treatments
While we generally regard jellyfish as a seasonal phenomenon, they are NOT.
Those of you who were cruising around over Christmas may remember a spate of Sea Wasps and the occasional Man O’War, which caught us all by surprise. However, to all intents and purposes, the northern end of the Caribbean sees a definite rise in jellyfish during summer months. For some, they present no worries, but for others a jellyfish sting can be a life-threatening experience.
Here’s a brief primer to jellyfish identification:
- Most prevalent are the Sea Walnuts, aptly named since they’re about the size of a walnut and their structure closely resembles that of a hulled walnut. These are innocuous to even the most sensitive swimmer.
- The most obvious are the Moon Jellies, smooth discs of faintly purple jelly, with four lilac rings grouped around the centre (the sex organs). A fine fringe of tentacles runs around the lower edge of the dome. These jellyfish range considerably in size from 3-4” in diameter to an incredible 3’. Moons can be easily moved with the palm of the hand applied to the rounded outer side of the body. The sting delivered by the tentacles is mild, somewhat akin to that experienced from stinging nettles but, if you’re caught in the middle of lots of them, this can be very uncomfortable.
Additional Jellyfish Identification: There are two other jellyfish regularly seen in our waters, which vie for the title of the worst jellyfish sting.
- They are the Sea Wasp and the Portuguese Man O’War. The Sea Wasp is tricky because it’s completely transparent and floats about 6” below the surface. A close relative of the Australian Box Jelly, the sea wasp delivers a really nasty sting. On particularly sensitive skin, it has been known to leave a “scar” similar to a burn.
- The Portuguese Man O’War is readily spotted thanks to its very distinctive ‘sail’. Bluish-purple in colour, the sail is often clear of the surface by 4” or so. The problem with the Man O’War is its tentacles which, at up to 30’ in length, are frequently chopped up by propellers into tiny, invisible, sections that deliver a hell of a punch.
Let’s take a look at how to avoid being stung by them, and what to do if you are.
Avoiding jellyfish stings is not difficult: at the very least, swim or snorkel wearing a T-shirt (this will also reduce the risk of sunburn, too). Lycra “skins” are a more extreme coverage, but you could also go for the Australian lifeguard and surfer trick of covering arms & legs with ladies pantyhose (tights) and a T-shirt!
In order to understand the whys and wherefores of treatment for stings, it’s useful to understand what happens when you’re stung.
Basically, the tentacles of jellyfish are stocked with minute cells called nematocysts. These deliver tiny “poisoned arrows” into your skin. The more you annoy the nematocysts (by rubbing or scratching, for example) the more they try to protect themselves and subdue their attacker, shooting more and more of their arrows into your skin.
Treatment of jellyfish stings is readily accomplished by flooding the area with vinegar.
Other decontaminants that are effective are rubbing alcohol, one-quarter strength household ammonia, or baking soda. A paste made from unseasoned meat tenderizer or papaya may also be useful. Simply rinsing the skin with sea water will provide relief until such time as treatment becomes available.
Once the sting has been neutralized, any tentacles adhering to the skin can be removed by applying a lather of shaving cream or soap and shaving the affected area.
Do NOT simply rinse the skin gently or apply ice directly to the skin. A forceful stream of freshwater may be sufficient to remove the tentacle or stinging cells, but non-forceful removal is more likely to cause the stinging cells to fire and increase the sting. Reapply the solution for about another 15 minutes, or until the pain subsides. A liquid antihistamine (Benadryl, Chlortrimeton, Piriton etc) is effective in relieving a mild allergic reaction.
A strong allergic from the jellyfish sting reaction can induce anaphylactic shock: an acute life-threatening syndrome.
Typical signs and symptoms of this condition include chest tightness, severe respiratory distress and changes in levels of consciousness. Many people who are aware that they suffer from strong allergic reactions carry an Epipen. Anyone who displays such symptoms should seek medical attention as quickly as possible.
The traditional seafarer’s remedy of urine on the jellyfish sting does work, but is not recommended as it can carry bacteria that may cause infection later. If you have no option but to use urine, male urine is the preferred brand as men are less prone to urinary tract infections. Once the pain of the sting has subsided, ensure that the area is properly cleansed (as if you wouldn’t!). Editor’s Note: Check out Sailing with Charlie: Jellyfish Stings for a humorous peeing incident while on charter.
Special thanks to VISAR