How to Identify Dangerous Marine Animals in Australian Waters

Australians like to tease overseas visitors about the dangerous animals lurking on land and in water. Unfortunately, this sense of humour is a coping mechanism for those living in a land beset by venomous and downright dangerous beasties. Before you venture in the waters off the Australian coast, be you a land-lubbing Aussie urbanite or a happy-go-lucky tourist visiting Australia, it can be helpful to know what to be on the lookout for...


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    Understand the dangers and balance these with common sense. The dangers in Australian waters are real and that is not even to mention rip currents and high waves that sweep away unsuspecting rock hopping tourists. A number of venomous marine animals inhabit Australian waters and knowing their habits can help to keep you safe from encounters, meaning that it is perfectly possible to come to an arrangement where you can enjoy your water activities without being harmed by the resident wildlife.
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    Look out for blue ringed octopus. This pretty but deadly little creature resides in rock pools and other still areas of water all around Australia's coastline. They are also known to make a home inside beverage cans and other containers that make their way to the bottom of lakes, artificial water spaces and the like, close to beaches, such as in Adelaide's foreshore area. If accidentally trodden on or picked up, this creature inflicts a fairly painless bite.[1] Unfortunately, its toxin is highly lethal and fast acting. To avoid it, don't pick up anything that could harbour this octopus - rocks in rock pools, cans lying in water or other containers. Never provoke it and watch where you tread. If bitten, immediate hospitalisation is required, with mouth-to-mouth resuscitation should breathing cease in the interim - mouth-to-mouth can keep a victim alive.[2] Place pressure on the wound, as for a snakebite. Note!: The blue ringed octopus is often harder to spot than one might think. In addition to being able to camouflage themselves to blend into their surroundings, their rings and namesake aren't quite as vivid as people think-- at least not until they're ready to bite. When at rest, a blue ringed octopus' rings are often very thin and can appear almost black, depending on the lighting. The neon blue that is often shown in pictures appears only as a last warning.
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    Beware the box jellyfish. Box jellyfish are found in northern Australia's coastline. This jellyfish has long tentacles that reach around 3 metres in length. These tentacles contain a highly venomous poison that can kill within minutes of contact. To avoid this creature, obey the signs. Most beaches will be signposted when these creatures descend en masse and you would do well to stay out of the water - New Scientist labelled these creatures as not "dim-witted ocean drifters" but "fast, active predators that hunt and kill [fish] with incredible speed and brutality."[3] Their season is usually October - May, so be especially cautious during this time. Get immediate medical help if stung and tell them it is a box jellyfish sting so that the ambulance or lifesaving club staff can bring antivenom. Use vinegar to neutralise the stingers that haven't fired and keep the sting "gravity neutral" - if it is too high, it will carry to the heart faster and if too low, it will cause swelling.[4]Apply limb pressure immobilisation if appropriate.[5] Cold packs can ease pain for conscious victims.
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    Avoid the stonefish. Stonefish are masters at the art of camouflage. They are found in the tropical coastline of Queensland and the Northern Territory. Stone fish have 13 venomous spines along the back that produce intense pain on contact. Most encounters are accidental, as waders tread on them unwittingly. Avoid the stonefish by not wading with bare feet, watching where you put your feet and being aware of where stonefish are known to reside. If stung, seek immediate medical assistance. In the interim, assist a victim by placing the sting into hot water (as hot as the victim can tolerate) and mouth-to-mouth if the victim stops breathing. Do not constrict movement of the venom in this instance.[6]
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    Take care to keep away from the stingray. Stingrays are mostly all over Australia, and can impact swimmers, divers, kayakers and other unsuspecting water lovers. They are bottom dwellers most of the time, tending to feed on the sand surface. Often they cannot be seen as they sit under the sand, with an eye possibly poking out. Generally, stingrays are not aggressive but they are equipped to protect themselves. Stingray injuries can include lacerations from the barb at the end of its tail, along with the potential for infection, intense pain and respiratory or other reactions in susceptible persons. Avoid stingray encounters by being careful where you place your feet and not provoking any that you encounter swimming in your vicinity; move away immediately and without panic. Drag your feet along the bottom as you enter the water. The grinding of the sand can be felt by stingrays and they will swim away. This is referred to as "the stingray shuffle." Seek medical assistance immediately if stung.
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    Don't swim with sharks. Australian coastline is a haven for many sharks and, in particular, for the great white shark and the grey nurse shark. A number of sharks are listed as endangered species in Australia. To keep out of the way of sharks, use common sense and keep away from areas known to be shark infested. Swim with other people and avoid swimming in dirty or turbid water. If you see a school of fish behaving strangely, this may be an indicator of the presence of sharks and you should leave immediately. Avoid swimming in deep channels, with pets, or near people fishing (the bait will attract the sharks).[7]
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    Avoid picking up shells if you don't know what they belong to. Cone shells contain extremely venomous snails. If you do not know what the shell belongs to, it probably is not safe to pick it up. If you are stung by a cone shell, seek medical help immediately.
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    Avoid touching a Portuguese man of war (blue bottle jellyfish) on land or going near one in water. These jellyfish can still sting a human or an animal, even if it is already dead. The sting can be mild to extreme pain. The sting depends on the jellyfish's size, and amount of involved tentacles. Blue bottle jellyfish travel in groups of 1000, and it is wise to stay out of water, especially if you see a pack of them. Portuguese man of war tentacles average 33 ft long, and get about 3 ft wide.


  • Teach children early what to be careful about and always remind them not pick up rocks, shells, cans etc. when they don't know what might be in a rock pool or other areas of a beach. Keep a close eye on young children and the things they are playing with. Always supervise swimming and take no risks with children when there might be a possibility of an encounter with any of these creatures.
  • Stay calm if you see a shark and try to get to shore fast,but smooth.
  • Do not wear jewelry or shiny objects. These reflect light, attract attention, and may act as a lure to sharks.[8]

Things You'll Need

  • Solid shoes for rock pool wading
  • Locals or surf lifesavers for information
  • Medical supplies in case of an emergency (vinegar, bandages etc.)

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