Dangerous marine life


Queensland’s beaches are great places to swim and surf, but be aware that sharks inhabit our coastline as well as estuaries, rivers, creeks, canals and streams.

We recommend you swim between the flags at patrolled beaches that have shark control equipment in place. If a shark is spotted, lifesavers will sound a siren or ring a bell, put up the red-and-white flag and tell you to leave the water immediately.

Safety tips

  • Don’t swim at dawn or dusk
  • Always swim in clear water (not in murky water, busy anchorages, estuary mouths or canals
  • Don’t throw good scraps or fish waste overboard (including in anchorages or where people are swimming)
  • Don’t swim where fish are being cleaned
  • Swim, surf, snorkel or dive with a buddy
  • Follow signage and swim between the flags at patrolled beaches.

Read more about being SharkSmart.

Marine stingers

Queensland is home to several species of dangerous tropical marine stingers, including the box jellyfish and the Irukandji.

Marine stingers are present in tropical Queensland waters all year round but the risk is higher during the marine stinger season (November–May).

Sting prevention

  • Always swim at patrolled beaches, between the red-and-yellow flags
  • Look for and obey safety signs
  • Don't enter the water when beaches are closed
  • Ask lifesavers for help and advice if you need it
  • Don't touch marine stingers washed up on the beach, they can still sting you
  • Swim in the stinger nets where provided
  • Consider wearing a full-body lycra suit to protect against marine stings.

Sting treatment

If stung, dial Triple Zero (000 and ask for an ambulance. While waiting for the ambulance, pour vinegar onto the sting and administer oxygen or CPR if required. Symptoms of Irukandji stings may take 20–40 minutes to develop—if in doubt, seek medical aid.

Read more about marine stinger first aid.


Crocodiles live in fresh and salt water in northern Queensland. Swim only in designated safe swimming areas. Even if there is no warning sign, there may still be crocodiles.

Safety tips

When in crocodile-inhabited areas:

  • obey all crocodile warning signs
  • always keep a watch for crocodiles
  • never provoke, harass or interfere with crocodiles, even small ones
  • never feed crocodiles—it is illegal and dangerous
  • be extra careful around water at night and during the breeding season (September–April)
  • stay away from the water's edge.

Read more about being croc wise.

Blue-ringed octopus

Blue-ringed octopuses are one of the world’s most venomous animals. They live in tide pools and shallow reefs all around Australia.

Bites can occur when people touch them or stand on them. While the bite might be painless, the venom in their saliva can be fatal.

If bitten...

Call Triple Zero (000) immediately and ask for an ambulance. When the ambulance is on its way, apply a pressure immobilisation bandage to the bite site. Start and continue CPR if required.

Other dangerous marine creatures