Stonefish Envenomation

Stonefish are widely distributed throughout tropical, marine waters of the Indo-Pacific with two potentially deadly stonefish in Australian tropical waters. The Estuarine Stonefish (Synanceia trachynis)and Australian Reef Stonefish (Synanceia verucosa) are recorded from much of the Great Barrier Reef in northern Queensland to far northern New South Wales.

The Reef Stonefish is the most dangerous venomous fish in the world. The unattractive, squat fish is well camouflaged against ocean floor debris and coral looking like an encrusted rock or a piece of coral. There are numerous erect spines along its dorsal fin that act like syringes which deliver highly toxic venom. They usually live on rubble or coral sea beds, often under rocks or ledges, but are also known to be able to bury in sand using their large pectoral fins.

Sea Snake Envenomation

There are more than 30 different species of sea snakes, all potentially dangerous to humans, in tropical northern Australian waters alone. All are elapid snakes, and thus related to the Australian land snakes. These snakes all feed on fish and spend some or all of their time at sea.

Irukandji Syndrome

A number of species of small and virtually invisible jellyfish will produce this potentially lethal reaction in humans if contact is made. These jellyfish including Carukia barnesii are found in warmer tropical waters off the northern coast of Australia.

Carukia Barnesi, a tiny jellyfish, is typically less than 1cm across the body, and has a single tentacle on each corner, reaching up to about 1 meter long. Both its body and its tentacles are armed with stinging cells (nematocycts) which contain mini harpoons that inject toxins into prey. They are found mostly in deep reef waters but can be swept inshore by prevailing currents. Most cases of stings are reported between November and May but they have been recorded on the East Coast in every month although more notably in the summer.