Okinawa Tourism Information:BeCarefulofthisseacreature!Habukurage(BoxJellyfish)

Be Careful of this sea creature! Habukurage (Box Jellyfish)

post : 2014.05.27 22:00

The blue sea, the blue sky, and a sparkling white sand beach!
The enchanting beauty of the sea of Okinawa makes you not to care how long a time passed.  But watch out for a dangerous creature in the water!

(The photo was provided by Okinawa Prefectural Institute of Health and Environment.)

Box Jellyfish is a highly venomous jellyfish to inhabit in waters of Okinawa and Amami.  When you get stung by a box jellyfish, it really hurts and the infected area will be swollen like an earthworm

The jellyfish has many poisonous needles called nematocyst and poison-filled capsules in its tentacles.  Once its tentacles touch something, the stingers project out and inject poison. 

The umbrella (a part except tentacles) grows up to be 10 cm or taller and the whole body including elastic tentacles grows up to be 150 cm or taller.  The box jellyfish is bluish, half translucent, so it is very hard to see it in the water.

When the water temperature gets higher during May and October, box jellyfish are found all throughout Okinawa.  Sometimes you can find them in the shallow part of the ocean, often as close to the surface as 50 cm.

When the jellyfish grow large during July and September, which is also the tourist season, we have accidental encounters with these jellyfish, and the number of accidents increases around this time every year.

Okinawa has so many beautiful, intact beaches, but on a beach without safety nets for keeping the jellyfish away, you need to be careful because there are rare chances of getting stung by jellyfish.

At big beaches run by resort hotels or local municipalities in Okinawa, they assign lifeguards and installed safety nets for keeping the jellyfish away.

I used to work as a lifeguard at a beach and aided and treated a swimmer when the swimmer got stung by a jellyfish while swimming outside of the net.

The pain is so terrible that even an adult gets a surprise that children who are not used to swimming or the elderly might get shocked and drowned.  The experience taught me a special care is needed.

For prevention, wearing a rash guard, a long-sleeve t-shirt and a spat to avoid exposing skin keeps the injury to a minimum by preventing the poisonous stinger from fully penetrating the skin. 

But what should we do if we get stung by a jellyfish?

As tentacles of jellyfish have many nematocysts, just touching them a little does not make all of stingers project out. But if you rub the area where you have been stung, it stimulates the remaining stingers to project out and your infected parts gets wider and worse.

The best treatment to stop stingers to project out is using kitchen vinegar. A bottle of ordinary kitchen vinegar is used for first aid.

First Aid for box jellyfish sting

1)  Get out of the water when you have been stung. Do not rub the area where you have been stung.
2)  Apply a lot of vinegar on the infected area. (Do not mix vinegar with water.)
3)  Gently remove the tentacles.
4)  Cool the infected area with cold water or ice it when it hurts.

Any ordinary kitchen vinegar such as rice vinegar, apple-cider vinegar is effective, but vinegar mixed with something for beverage purpose does not work.

Also acetic acid for medical care promotes stingers to project out.  As alcohol promotes the projection of stingers, too, if you get stung by jellyfish, do not use alcohol as an antiseptic. Just apply kitchen vinegar immediately.

Please note that kitchen vinegar is not effective all kinds of jellyfish.
If you apply vinegar to katsuonoeboshi, (Portuguese Man O’ War), it promotes stingers to project out.
Different from box jellyfish, Portuguese Man O’ War is a bright blue-colored, about 10 cm tall, small jellyfish.
If you get stung by Portuguese Man O’ War, you experience symptoms of erythema (red welts due to a skin inflammation), blister, etc.

If there is a lifeguard on the beach, please ask the lifeguard to get a help and give you first aid.  If the pain is serious, you need to be taken to a hospital.
Not only for jellyfish sting, but for any kind of accident while swimming, please dial "118" wherever you are when you encounter a marine accident emergency to ask for help.
(You can be connected by using a mobile phone or PHS.)

There are other things I would like you to be careful about while playing around the sea. 

When I was a lifeguard at a beach, the most frequent damage happened to swimmers was burn injury caused by sunburn.  
When you look at a beautiful sea, you might forget how long you have been under the sun.
You have to be careful not to get sunstroke or sunburn under the scorching sun.
As you experience strong sunshine in Okinawa, please take a rest every hour under the cool shade of a tree and have plenty of water and salt content.  

In addition, please check a tide table before going to the beach.  
The tide will go down considerably at low tide of a spring tide, so sometimes there is little sea water around the safety net and you cannot go into the water.
If you take a quick glance at a tide table and decide to go swimming before or after high tide, you can enjoy swimming comfortably.
*You can check tide condition in Okinawa here.

If you go to the beach with a good knowledge, you can enjoy a safe, comfortable stay there.  
I hope the beautiful ocean of Okinawa will be a pleasant memory for you!

* For more information on box jellyfish, please contact “Okinawa Prefectural Institute of Health and Environment” 

Okinawa Prefectural Institute of Health and Environment 

Address: 2085 Oozato, Nanjo City
TEL: 098-945-0083
Hours: 9:00 to 17:00 (Weekdays)
Parking: Availble
* Before your visit, please call them to tell the purpose of your visit.

Okinawa CLIP Photo Writer  Takano Nakano