Beware Of The Dangerous Coral In The Caribbean That Tourists Often Mistake For Seaweed

On a tropical vacation, snorkeling and diving are two must-try activities for unique thrills and breathtaking beauty. You can swim in warm, light-filled waters, interact with curious sea animals, and glide over vibrant coral reefs that formed thousands of years ago. However, as with any adventurous undertaking, there are some risks that you should be aware of, including decompression sickness, drowning, watercraft-related accidents, and more. Additionally, while the majority of marine life you'll encounter is innocuous, some can be hazardous to humans, and one such harmful creature is the deceptively pretty yet toxic fire coral.

This species (Millepora dichotoma) can be found in tropical and subtropical waters all over the world, particularly in shallows that experience strong currents and high amounts of sunshine. Despite its misleading name, fire coral isn't actually a coral — it's a hydrozoan more closely related to anemones and jellyfish. But just like coral, it's a colony-forming organism that springs up in reefs, making it difficult to differentiate. In fact, it is often mistaken for seaweed, particularly by tourists, due to its coloring (it's found in shades of green, brown, and yellow). Although it may be beautiful to look at and photograph, underwater enthusiasts should beware: it's one of the 12 dangerous creatures to look out for when snorkeling in the Caribbean.

If you've been stung, you'll know it — because you'll feel a painful burning sensation up to 30 minutes after contact. While fire coral isn't deadly (thankfully), it's not a pleasant experience. The pain can last for several hours, and it's usually accompanied by a skin rash that may take days or even weeks to fully subside. Even worse, a cut or laceration from a fire coral can cause necrosis (the death of cells in tissue) around the wound, which may lead to a serious infection.

It can be challenging to identify these tricky underwater chameleons because they're found in reefs and can grow on hard structures, like rocks or dead coral, taking the shape of the object. That being said, there are a few characteristics to look out for. While it comes in an array of shapes and colors, most fire coral is either brownish-green or brownish-orange with white tips, and it often appears in a branching formation. Fire coral also has tiny yet visible stingers that look like protruding hairs — the source of the powerful poison discharged by the organism.

The most obvious way to avoid a nasty sting is to ensure that you stay far enough away from the coral and don't touch anything — this is also a general best practice for snorkeling near coral reefs without hurting the environment. If you're inexperienced underwater, ensure that you've listened carefully to the briefing before the dive, and stay close to your guide during the excursion. Additionally, pay attention to your buoyancy and keep an eye out for what's directly below, so that there's no accidental contact. You should always wear fins when snorkeling or diving to protect your feet and give you better movement in the water. As much as possible, maintain a horizontal position and avoid standing or kneeling on anything unless instructed to do so by your guide. If available, wear a full-body wetsuit, which will both keep you warm and protect your skin from unwanted exposure.

Finally, if you do experience a fire-coral sting, rinse the area with seawater and apply isopropyl alcohol or acetic acid (household vinegar will work). Ensure that you keep it clean and dry. If you develop symptoms of an allergic reaction, seek medical attention immediately.