Dangers of the Reef

Dangers of the Reef

It's true: there are creatures in the water here that can kill you, or at least inflict some serious pain. The most ubiquitous offenders near the tropical mainland are jellyfish; the sting of the tiny, transparent Irukandji, no bigger than a thumbnail, can cause severe pain, vomiting, and soaring blood pressure, which may be life-threatening to people with already high blood pressure or diabetes. Even more dangerous, however, are the deadly Chironex jellyfish—commonly known as sea wasps or box jellyfish. These transparent, cube-shaped creatures are the most venomous sea creatures on Earth; their stings, which cause the lungs and heart to stop functioning, are fatal unless they are treated within three minutes. Jellyfish season unfortunately coincides with the tourist season and prime beach weather; many of the most popular beaches in North Queensland have stinger nets, which will keep box jellyfish out of the swimming areas.

The good news is that on the outer reef and islands jellyfish aren't a problem. Here, though, another danger you need to be careful of is the coral. Millepora, or stinging coral, ranges in form from large upright sheets and blades to branching, antlerlike stalks with a yellow-brown color. If this coral inadvertently scrapes or tears your skin, you'll get painful, burning welts. Try to swim with your arms and legs close to your body, and of course notify someone if you think you have rubbed up against anything.

Sharks are present in the waters of the inner and outer reef but, unlike jellyfish, aren't likely to come near you. The small sharks off the shores of North Queensland and around the inner reef islands only eat fish. Tiger sharks and hammerheads, which hunt in deeper waters, tend to swim away from people. You are unlikely to see a great white shark while on the reef; they prefer the colder waters of the southern Pacific. But even if you do see one, remember that these mythically fearsome creatures aren't hard-wired to make a meal out of you. There are plenty of convenient nonhuman feeding options available on the reef. They're only likely to pursue a human if provoked, or if the irresistible smell of blood is flowing in the water.

There are other more exotic but equally dangerous creatures lurking around the reef, such as stonefish and sea snakes. But your worst enemy in this part of Australia—whether you're in or out of the water—is the sun. The ozone layer in Australia is almost nonexistent, and one in three Australians eventually develops some form of skin cancer. Many a snorkeler has had a day on the water ruined by a nasty sunburn on the back of his or her legs. Be sure to coat yourself in sunblock consistently the whole time you're visiting the reef.