Marine Stingers FAQ Marine Stingers FAQ

With 74 Islands and the Great Barrier Reef on its doorstep, the Whitsundays is famous for its water-based activities whether it is snorkelling, diving, or just going for a leisurely swim.

However, it is important to remember that we share the ocean with other animals which call marine waters their home. Some of these creatures such as the Irukandji and Box Jellyfish (Chironex fleckeri) are potentially dangerous. Below are some commonly asked questions in relation to marine stingers.

What are Irukandji?
Irukandji is a group of jellyfish which are known to cause symptoms of a potentially dangerous syndrome called Irukandji Syndrome. There are currently 14 known species of Irukandji, however only a few of these species have the potential to occur in the waters around the Whitsundays. Irukandji can occur coastally and around the reef and islands.

What is Irukandji Syndrome?
Irukandji Syndrome is a syndrome which can affect people who have been stung by an Irukandji jellyfish. Whilst the Irukandji sting itself can be relatively mild, the symptoms of the Irukandji Syndrome, in very rare cases, can be life-threatening. Symptoms of Irukandji Syndrome can take 5 to 45 (typically 20-30) minutes to develop after being stung. Some symptoms include:
• Lower backache, overall body pain and muscular cramps. The pain from this can be severe.
• Nausea/vomiting
• Chest pain and difficulty breathing
• Pins and needles
• Anxiety and a feeling of “impending doom”
• Headache, usually severe
• Increased respiratory rate
• Piloerection (hair standing on end)
• High blood pressure which can lead to stroke or heart failure
• A sting is rarely evident – if present, usually just a pale red mark with goose pimples or sweating.

Are Irukandji only prevalent in Australia?
No. Species of Irukandji occur in S.E. Asia, the Caribbean, Hawaii, South Africa and even the United Kingdom. Australia is leading the study of these creatures, which is probably the reason why the jellyfish may be wrongly associated with occurring only in Australia.

What are Box Jellyfish?
Whilst globally the term “Box Jellyfish” is the general term given to any jellyfish which has a bell (head) shaped like a box, in Australia the name almost always refers to a particular species of jellyfish called Chironex fleckeri. Chironex is often regarded as the most venomous animal on the planet. It has the potential to kill a healthy adult in as little as 2-3 minutes. The species can grow quite large – up to 30cm across the width of its bell (head), with up to 60 tentacles, each stretching up to 3 metres. Box jellyfish usually inhabit costal areas including rivers; however do move offshore on occasions.

What are the symptoms of being stung by a box jellyfish?
A sting from a box jellyfish is far more painful than a sting from an Irukandji, with numerous visible weals. Those who are stung will usually scream in pain, with very severe stings causing respiratory distress and cardiac arrest within just a few minutes. Tentacles will often be present wrapped around the skin where the person has been stung.

When is Stinger Season?
Experts prefer not to use the term “stinger season” as this implies that jellyfish are only prevalent during this time. Stings have occurred at all times of the year, however are more prevalent during the months of November to May. November to May is therefore termed “high season” or “peak season” for marine stingers as they are more active and more numerous during this time.

What are my chances of getting stung by an Irukandji?
Rare. Out of the millions of “people days” each year in the Great Barrier Reef waters, in a particularly bad year, only around 100 Irukandji stings occur in Queensland which require medical treatment. However, getting stung by one of these creatures, regardless of how rare, can be life threatening and at the very least can ruin your holiday. It is therefore important to follow a few simple precautions to further lessen the risk of being stung.

How can I prevent being stung?
• Wear protective clothing such as a full body lycra or neoprene suit. This is the number 1 way of preventing stings as suits protect up to 75% of the body and cover areas where stings more commonly occur. Not all suits offer equal protection - lycra or neoprene offer the greatest protection. Such suits are also excellent for sun protection and protection from coral cuts, etc.
• Wear protective clothing, even if wading, as most box jellyfish stings occur when wading.
• Enter the water slowly (i.e don’t run in) as Box Jellyfish will often swim away if given the time and opportunity to do so.
• Swim between the flags and follow Life Saver’s advice if swimming at patrolled beaches.
• Be aware of high risk conditions for Irukandji – sustained NE winds, flat or calm weather, sea lice felt in the water and/or salps present (look like crushed ice washed up on the beach, or a machine gun bullet belt when swimming in the water).
• Always carry vinegar when going boating or undertaking other marine activities.

What is the best way to treat jellyfish stings?
1. Call for medical help (ring 000)
2. Assess the patient and perform CPR if necessary
3. Douse the sting site with vinegar as soon as possible. Vinegar inactivates the stinging cells, preventing them from injecting more venom.
4. Reassure the patient and keep calm until medical help arrives.
5. Wait at least 45 minutes before re-entering the water as symptoms of Irukandji syndrome can take a while to develop.
6. If in doubt, treat as Irukandji.

Are Stinger Nets/Enclosures effective at preventing jellyfish stings?
Stinger nets/enclosures are very effective at preventing the more dangerous Box Jellyfish (Chrionex fleckeri) from entering the enclosure. Data has shown that box jellyfish stings have dropped significantly since stinger nets were introduced. However, stinger nets cannot prevent the much smaller Irukandji from entering the enclosure. This is due to the fact that the holes in the netting cannot be made any smaller as the nets would clog too quickly and have to be removed for cleaning several times a day. It is therefore important that you exercise caution when swimming in stinger enclosures and do not interfere with the enclosure or floating pontoon.

Where can I get more information?
Contact Council’s Environmental Health Services on telephone (07) 4945 0200, or visit