Most surfers, snorkelers, and ocean swimmers know that sharks and currents aren’t the only hazards in ocean water. Jellyfish are becoming an increasing danger all over the world.
There are over 200 known species of jellyfish, and 70 of them sting. Jellyfish can detect changes around them, and react to changes. When they contact something solid, their reaction is to sting. The stinging mechanisms are nematocysts, capsules containing hollow coiled threads with barbs all along their length. There are hundreds of nematocysts on each tentacle and feeding arm of a jellyfish.
The most dangerous jellyfish is the sea wasp, a small box jelly found from Australia to Malaya. Their sting can be deadly because of the high toxicity of their venom. A person stung by a sea wasp can die within minutes, either from the toxin or from drowning because of the paralysis the sting causes. If you’re in those waters, wear a full-body wetsuit to survive.
Sea wasps aren’t in American waters but larger box jellyfish are. These jellyfish don’t have the dome or bell shape that characterizes the class. Their sting is very painful, and if they are swarming and you’re caught in the swarm, the number of stings can be lethal. If warnings are posted, or if you can see them, stay out of the water.
The other dangerous jellyfish is the Portuguese man-of-war. These aren’t true jellyfish, but have the characteristic dome shape. They’re recognizable by their blue color. Even dead ones washed ashore can sting. They’re increasing in number as ocean temperatures rise, and moving steadily north.
You can survive a jellyfish sting by treating it with vinegar, so carry a bottle or two of that along with your bottle of drinking water. Carry allergy medications in your pack too because allergic reactions are common. Drench the sting with vinegar, then wipe the area with sand or a towel. Don’t touch it as you could be stung as well. Get the injured person to a medical facility as soon as possible, especially if he’s showing signs of anaphylactic shock, such as having trouble breathing.
