Biosecurity authorities are undertaking investigations after a single, mature Asian green mussel was found on a boat moored in Trinity Inlet.

The mussel (Perna viridisis) is an invasive and prohibited pest, which is poisonous to humans if eaten and capable of out-competing native marine life.

The vessel is understood to have been moored in the inlet since 2013.

The Asian green mussel was only located by Dawul Wuru Aboriginal Corporation rangers after the boat was recently moved to be cleaned.


The species, which hasn't been detected in Cairns since 2014, can be introduced via a ship’s ballast water, as biofouling on boat hulls and through internal seawater systems.

It has been found in Cape York and Gulf of Carpentaria waters several times in recent years. 

A spokesperson said the Department of Agriculture and Fisheries (DAF) understands the mussel was already present in the environment before attaching to the vessel.


“This is being treated as an environmental detection – the result of a spawning event in the area leading to the settlement of this individual.”

The mussel’s 17.5-centimetre length – equal to the largest recorded Asian green mussel – suggests it had been on the boat for an extended period of time.

“Recent Q-SEAS marine pest surveillance activities were undertaken in the area and are awaiting laboratory analysis,” the spokesperson said.

“We are also working with Ports North and Marine Safety Queensland to identify high risk vessels and mooring piles so we can conduct further investigations.”

The Asian green mussel is bright green when young and dark green to brown when mature, with a life span of about two years. 

They are fast-growing and can spread rapidly in new locations, particularly where local predators are limited. 

Minister for Agriculture and Northern Australia David Littleproud said the department is working on national biofouling regulations to help keep the pest out of Australian waters.

“We’re lucky this detection was made by Yirrganydji rangers who are on the look-out for these types of exotic pests,” Minister Littleproud said.


“I’ve said for a long time that the monitoring and surveillance work Indigenous rangers do is crucial to keep Australia’s biosecurity safe, and this proves it.

“Biosecurity is everyone’s responsibility, whether you are government, a business or just someone taking the boat out fishing for a weekend.”

If you think you’ve found an Asian green mussel, immediately report it to Biosecurity Queensland on 13 25 23 or online.


Main points

  • A prohibited exotic Asian green mussel was recently discovered in Trinity Inlet, Cairns
  • The mussel was found on a boat that had been moored since 2013
  • It is usually brought into Australia on ships arriving from Asian or Pacific ports
Internal examination indicated it was a mature male capable of reproduction.
Department of Agriculture and Fisheries
They are at the frontline.
David Littleproud
Minister for Agriculture and Northern Australia