Box Jellyfish – The habu of the sea.


Who can resist taking a dip in the ocean? There’s nothing like it and Okinawa is no exception. After all a trip to the beach is a fan favorite among tourists regardless the hundreds of other things the island has to offer. Although it might be tempting to find an empty spot of shore, strip down to your skivvies and jump right in there are some hazards you should be aware of. One of those hazards is the box jellyfish. 

The box jellyfish or the habu jellyfish as it is sometimes called here in Okinawa is a cube-shaped jellyfish which, much like the habu, is known for its potent venom. A sting by one of these squishy menaces is very painful and can sometimes be fatal (depending on the severity and the species). Unlike other jellyfish the box jellyfish hunts its prey rather then just drifting along and can reach speeds of 1.6 meters per second. What makes box jellyfish dangerous are it’s tentacles which contain about 500,000 harpoon-shaped mechanisms that inject their dangerous venom. In humans once the tentacle is stuck to your skin it will pump in venom (nematocysts) which causes a stinging sensation followed by agonizing pain.

So what do you to if you have been stung by a box jellyfish? The first and most important thing to go is get out of the water. Once you are safely out of the water you are going to need to stop the stinging which you can do by immediately rinsing with vinegar. Although vinegar is not something most people think to bring to the beach it is a good idea especially if you’re at a beach which has not taken steps to protect patrons from jellyfish. DO NOT USE fresh water or tap water because it may reactivate stinging cells and make the entire situation worse. Some sources state that you can then carefully pick off the tentacles ensuring that you do not make direct contact with them to avoid secondary stings. If doing this you should also ensure that you continue to rinse with vinegar throughout the process. Next you’re going to need to seek medical attention. The most important thing to remember during this process is to never rub the affected area with your hand, towel, sand or anything else. This will spread the injury and cause more burning.

The big question is how to prevent getting stung by a box jellyfish. The easiest way to do this is to only swim in areas which have what is called a jellyfish or stinger net. You’ve probably already seen these nets at popular beaches and wondered why people are swimming inside this contained area and nowhere else. It’s not because the Japanese are scared of the ocean (like one blog I read suggested) but rather because these nets create an area for swimmers which is safe from jellyfish. Something else you can do is avoid swimming in areas which have “Danger Jellyfish” or “No Swimming” signs. The signs are there for your protection so follow them.

If you laugh in the face of danger (muah ha ha) or simply can’t be tamed by a jellyfish net then there are a few things you can do to protect yourself although it is important to remember that you will be at a greater risk. Firstly wear a wet suit or long sleeves and leggings while swimming. Some sources also recommend wearing nylons which are known for preventing stings from box jellyfish. Above all never swim alone.