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New Zealand green-lipped mussel (Perna canaliculus)

Victoria has declared the New Zealand green-lipped mussel a noxious aquatic species, and live specimens must not be brought, kept, sold, transported or released in Victoria’s protected waters. If it establishes outside its native range, it may compete with native marine life and foul natural and built surfaces.

Key facts

Type: Pest animal, invertebrate.

Native to: Coastal waters of New Zealand.

Established in: VIC.

Other names: Green-lipped mussel, Greenshell mussel, Green mussel.

Best time to act: Inspect accessible shorelines at low tide, and report suspected mussels promptly rather than waiting for a particular treatment season.

Identification

  • It has a two-part shell that is elongated and wedge-shaped, with a tapering end.
  • The shell is generally dark brown to greenish on the outside, often with a distinctive green margin or lip.
  • It attaches to hard surfaces using strong threads called byssal threads.
  • Adults can grow to around 10 to 20 centimetres long.
  • Look-alike: It may be confused with other mussels, including native mussels; the green shell margin can help distinguish it, but suspected specimens should be checked by an expert.

Where it lives

It lives attached to hard surfaces in coastal waters, from the intertidal zone to shallow subtidal areas, and could occupy suitable sheltered marine or estuarine sites in Australia.

Why it matters

  • Dense populations can compete with native mussels and other organisms for space and food.
  • Large mussel beds can change the structure of marine habitats.
  • Attached mussels can foul boat hulls, infrastructure and aquaculture equipment, creating costs for operators.

How it spreads

  • Its larvae can disperse in seawater before settling and attaching to a surface.
  • Attached mussels may be moved on boat hulls, trailers, ropes, fishing gear or aquaculture equipment.
  • Moving live mussels or contaminated gear between waterways can help spread the species.

Control methods

  • Report suspected specimens promptly to Agriculture Victoria; do not move or release live mussels.
  • For a small detection, physical removal should be done only with biosecurity guidance, with removed material contained and disposed of so it cannot return to the water.
  • Use only control methods approved by the relevant biosecurity authority; herbicides are not a suitable treatment for marine mussels.
  • Recheck the site after treatment and continue monitoring for mussels or new settlement.

Site hygiene and welfare

  • Before leaving a waterway, inspect boat hulls, trailers, ropes and other gear, remove attached organisms, and clean and dry equipment before using it elsewhere.
  • Do not transfer live mussels, seawater or contaminated gear between waterways.
  • Use methods set out in the national model codes of practice and standard operating procedures for the species.
  • Coordinate control with neighbours and the local government biosecurity plan, as isolated effort is quickly undone by reinvasion.

Classification by state

  • Australia (national): Priority marine pest. On the Australian Priority Marine Pest List, agreed by all governments as a marine pest of national concern. National priority exotic pest. On the National Priority List of Exotic Environmental Pests, Weeds and Diseases, so any new detection should be reported straight away.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Prohibited matter. It is an offence to deal with it, and you must notify NSW DPIRD as soon as you become aware of it.
  • Victoria: Noxious aquatic species. Declared a noxious aquatic species under the Fisheries Act 1995, so it must not be brought into Victoria, kept, sold, moved or released into waters. Report any sighting to the Victorian Fisheries Authority on 13 FISH (13 3474).
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Noxious fish. Prescribed as a noxious fish under the Fish Resources Management Regulations 1995, so it must not be brought into WA, kept, sold or released. Report any sighting to FishWatch on 1800 815 507.
  • Tasmania: Not a declared pest. Not a declared pest or prohibited matter in Tasmania. Importing animals is still controlled by Biosecurity Tasmania.
  • Northern Territory: Not a declared pest. Not on an NT declared or prohibited list. Check with the NT Government before keeping, moving or releasing it.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria

Sources