A fast grower that forms dense colonies on any hard surface - including your boat, shells, reefs, wharf piles, aquaculture structures and mooring lines. Wakame crowds out native species and steals their light and space. This could mean our favourite dive spots are never to be the same again.

How to identify this species:

• Golden to dark brown 

• Slimy to touch

• Distinct mid-rib (if plant >5cm)

• Can have an eroded top on blade of adults

• Mature plants have filled reproductive structure at base of plant

• Juveniles appear as single leaf

Photos / Northland Regional Council and others

This species is known to be in the following locations in Northland, Auckland, Marlborough, Golden Bay, Wellington, Canterbury, Southland , Gisborne. If you find it outside this area, please report it.

Parengarenga Harbour, inner Hauraki Gulf, Tauranga, Gisborne, Napier,  Port Taranaki,  Wellington Harbour Marlborough Sounds (Picton, Tory Channel), Nelson, Golden Bay, Kaikoura, Lyttelton Harbour, Timaru, Otago, Bluff, Breaksea and Dusky Sounds (Fiordland), (Easy Harbour, Halfmoon Bay and Paterson Inlet (Rakiura/Stewart Island)

This list is correct to the best of our knowledge at the time of publishing - for a full list of marine pest locations, please go to the Marine Biosecurity Porthole If you find it outside this area, please report it.