A number of species have been declared nationally as Unwanted Organisms. For the most up-to-date list of Unwanted Organisms, visit the MPI website.

Unwanted Organism status means that it is prohibited from sale, propagation and distribution in accordance with sections 52 and 53 of the Biosecurity Act. Freshwater gold clam is not a pest to be managed under our Pest Plan, however, unwanted organisms may be controlled in other ways in accordance with our Biosecurity Strategy.

     

Asian paddle crab

Management: Unwanted Organism | Asian paddle crabs have a 12 cm shell, paddle-like hind legs, and spines on their claws and shell, with colours ranging from pale-green to chestnut-brown; they inhabit estuaries and coastal zones.

Read more

Clubbed tunicate

Management: Unwanted Organism | Styela clava, or clubbed tunicate, is a long, club-shaped marine animal that can grow up to 160 mm, featuring a knobbly surface, two siphons on top, and is typically found attached to various structures in shallow waters.

Read more

Didymo

Management: Unwanted Organism | Didymo is a thick pinkish-brown layer that covers rocks and plants in freshwater, often forming flowing 'rat tails' with white-cream ends that look like soggy toilet paper, and feels like wet cotton wool.

Read more

Exotic caulerpa

Management: Unwanted Organism | Exotic Caulerpa has green, oar blade-shaped fronds up to 10 cm long, growing from horizontal stems that form dense mats on the seafloor.

Read more

Freshwater gold clam

Management: Unwanted Organism

Read more

Great willowherb

Management: Unwanted Organism

Read more

Mediterranean fanworm

Management programme: Unwanted Organism | The Mediterranean fanworm is a tube-dwelling worm with a leathery appearance, growing up to 80 cm and featuring a large spiral of colourful feeding tentacles.

Read more

Purple loosestrife

Management: Unwanted Organism

Read more

Yellow Flag Iris

Management: Unwanted Organism. Yellow Flag Iris Y is poisonous to humans and animals. It grows up to 1.5 meters tall, with broad, flat, sword-shaped leaves, and bright yellow flowers.

Read more

Undaria

Management: Unwanted Organism | Undaria is an invasive seaweed that grows 1 to 2 meters long. It has a crinkly texture and comes in brown, green, and yellow colours, with a noticeable midrib and a spiral structure at the base.

Read more