Underwater, you should only have to avoid sharks and animals that bite, right? (See our earlier post for tips on dealing with hazardous marine animals!)
A lot of sea creatures use venom to kill prey and defend themselves. Fortunately for us, humans are not their normal prey — however, it can mean bad news for you if you get up too close and personal with one, either intentionally or more often, accidentally.
(What’s the best defense? A wetsuit or Lycra suit – click to view!)
Envenomation (the process which venom is injected) can occur from simply brushing against an organism, a puncture or from a bite. In this post, we’re going to focus on organisms who deliver venom by contact, since these are the most common things we encounter as divers.
Members of the phylum Cnidaria, many of these organisms contain cells called nematocysts, or special cells in their tentacles or extremities, which have a barbed thread that delivers a toxin. Contact can trigger millions of nematocysts to pierce the skin and inject venom, which if you’ve ever been stung, you know can hurt!
Corals: Commonly called fire coral, these stings are generally fairly mild. A rash can form and may take days to subside.
Hydroids and Anemones: Hydroids, which look like feathery plants, and anemones can be very pretty but don’t touch or you may regret it! Reactions are usually similar to coral encounters.
Regular Jellyfish: Most jellyfish stings are relatively mild, but some can be very painful, causing rash, blisters and swelling. Most jellyfish drift and can be avoided, but their tentacles can hang far from the main body, so if you see any, be prepared to encounter a tentacle.
Portuguese man-of-wars: These look like floating, iridescent balloons and they can pack a wallop of a sting! With tentacles that average 33 feet long, but can reach 165 feet, snorkelers and divers on the surface may get tangled in a tentacle and not even know what got them. You can even be stung from a dead one.
Sea Wasps / Box Jellyfish: These species live in waters off Northern Australia and throughout the Indo-Pacific. Their venom is considered to be among the most deadly in the world, often causing divers to go into shock and drown, or die of heart failure before they reach the surface. Survivors often suffer severe pain for weeks and scarring. These organisms can propel themselves better than regular jellyfish, so if you see one, move away!
The above are general recommendations. If you plan to dive in areas where you’re likely to encounter a venomous organism, do a little research on treatment and make sure you bring along the necessary treatment items such as vinegar (a spray bottle works best). DiversAlertNetwork (DAN) is a reliable source of information.
Have you been stung while diving or snorkeling? Let us know how you treated it in the comments below!
Video attribution: https://www.youtube.com/channel/UC98qLnGlZG9RLrv_zVsf32Q
Image attribution: https://www.flickr.com/photos/gocardusa/