How dangerous can a gelatinous sac of straggly tentacles be? A jellyfish’s soft, transparent body appears vulnerable to all sort of prey, and a diver may be surprised that a jellyfish can survive to grow to maturity without being eaten. Yet, a jellyfish’s delicate body is anything but unprotected. The tentacles of a jellyfish contain uncountable numbers of stinging cells, called nematocysts, which effectively protect it from many potential predators and are used to stun small prey.
Depending upon the species of jellyfish, contact with the stinging cells can injure, or even kill a human being. But how much of a threat are jellyfish to scuba divers?
Are You Likely To Be Stung by a Jellyfish While Scuba Diving?:
No. Jellyfish are not a major threat to scuba divers. The majority of jellyfish species tend to stay near the surface of the water, and are more of a threat to swimmers and beach-goers than they are to divers. In addition, a jellyfish must contact a person’s bare skin in order to sting. Generally, divers wear wetsuits or dive skins and have little exposed skin to sting.
Dive guides and local dive centers will usually alert divers if dangerous species are present. If a diver spots a jellyfish underwater, he should take care to stay at least a few meters away. Some species of jellyfish have transparent tentacles over one meter in length which may be difficult or impossible to see underwater.
Are Jellyfish Stings Dangerous?:
The effects of jellyfish stings can range from mild pain and stinging, to skin irritations and blisters, to respiratory problems, cardiac arrest, and death.
The toxicity of a jellyfish sting depends upon the species of jellyfish and the reaction of a person’s body to the jellyfish venom.
The most toxic type of jellyfish is the Box Jellyfish (Chironex fleckeri and Caruka barnesi) found in Australia and some regions of the Indo-Pacific. The venom of the Box Jellyfish has been known to kill a person in five minutes.
People react differently to jellyfish stings. Consider a jellyfish sting as a “dose” of poison. The smaller the person, the greater the effect of a jellyfish sting will be. Just as some people are highly allergic to bees and may go into anaphylactic shock from a single sting, other people may be unusually sensitive to jellyfish venom and may have a similar severe reaction.
How Should a Diver Treat a Jellyfish Sting?:
Most diving safety organizations recommend vinegar as immediate first aide for a jellyfish sting. Vinegar, which neutralizes a jellyfish’s stinging cells, has two primary benefits – to minimize pain and discomfort, and to stop the delivery of jellyfish venom. When stung by a jellyfish with exceptionally toxic venom, such as that of the Box Jellyfish, the immediate application of vinegar to neutralize stinging cells and prevent more venom from entering a diver’s body may be the difference between life and death. Vinegar should be in every dive boat’s first aid kit. If vinegar is not available, a paste of baking soda may be used to neutralize sting cells. Salt water may be used as an additional rinsing agent if necessary.
In no circumstances should fresh water be applied to a jellyfish sting as fresh water may cause additional stinging cells to fire. Urinating on jellyfish stings is not recommended to neutralize jellyfish venom (sorry).
Jellyfish tentacles tend to stick to a diver’s skin and must be removed once the stinging cells are neutralized. Shaving affected area with a razor has proven very effective in removing tentacles. Other suggestions include using tweezers or thick gloves to pry the jellyfish tentacles away. Any abrasive material, such as sand, may be used to scour the sting area when other methods are not available.
Cold and hot packs (as long as they are completely dry) may be used to alleviate the pain of a jellyfish sting. Most doctors recommend hydrocortisone cream to be applied topically to the stung area.
The victim of a jellyfish sting should be monitored carefully for signs of shock, difficulty breathing, nausea, and other signs of severe allergic reactions. If any allergic reaction is suspected, be sure to contact a doctor immediately.
In most cases, an encounter with a jellyfish while scuba diving is anything but dangerous. Jellyfish are among some of the oceans most surprising and fascinating creatures, and it is enchanting to watch their pulsating movements as the drift through the water. Enjoy your jellyfish encounters, just make sure to give them plenty of space!