Asian brown mussel

Perna perna

If this mussel established in New Zealand, it could make life hard for our native green-lipped mussels.

About the Asian brown mussel

This mussel is a native of the western Indian Ocean and the west coast of Africa. It's a close relative of the native green-lipped mussel. It lives in similar places and eats the same food as our iconic native species.

Why this is a problem for New Zealand

The green-lipped mussel is culturally and economically important to New Zealand. If the Asian brown mussel got here, it would compete for food and space with green-lipped mussels.

Asian brown mussels thrive on human structures. They can create fouling problems in places like jetties, buoys, and boat hulls.

They could also bring new diseases to New Zealand that could harm our native shellfish.

How could it get here?

This pest is most likely to arrive in New Zealand hitchhiking on the hull of a boat. Boats visiting our waters need to keep their hulls clean.

Even if you don't travel overseas, keeping your boat hull clean can stop pests spreading.

The mussel could also arrive in ballast water.

Where will I find it?

You would be more likely to find Asian brown mussels in the north of New Zealand, as they need warm temperatures to reproduce. But they can survive nearly anywhere in our waters.

How to identify Asian brown mussels

It's difficult to tell the difference between this pest species and other mussel species in New Zealand.

Asian brown mussels are generally a brown or brown-yellow colour and can be tinged with green around the edges. They grow to a length of about 90mm but can reach up to 120mm.

The main difference between this mussel species and others is the angle of the shell.

Green-lipped mussel with curved bottom shell edge, 2 brown mussels with straighter bottom shell edge
A. Green-lipped mussel B, C. Asian brown mussels with straighter shell edge.
Dark blue-black coloured mussel, 2 larger green-lipped mussels, 2 brown mussels, and a smaller, brown coloured native mussel
A. Blue mussel B, C. Green-lipped mussels D, E. Asian brown mussel F. Native bearded mussel.

If you find Asian brown mussels

  • take a photo
  • collect a sample
  • record the location and landmarks
  • call MPI on 0800 80 99 66

Find out more

Note: This information is a summary of the Asian brown mussel's potential impacts on New Zealand.

Last reviewed: