These species of Caulerpa demonstrate aggressive overgrowth qualities when introduced outside of their native ranges. This quality can alter native sea floor habitats, which affects a broad range of marine species.

Visit the MPI website for more detailed information

How to identify this species:

• A green seaweed with fronds up to 10 cm long that rise from long runners or roots known as stolons. 

• In favourable conditions, it can spread rapidly, forming vast, dense beds or meadows of many hectares.

You can help stop the spread of exotic caulerpa:

• Know where exotic caulerpa is – check: www.biosecurity.govt.nz/caulerpa for maps, information about legal restrictions in some areas on some boating and fishing activities, what caulerpa looks like and how you can prevent spread.

• Respect the rules about anchoring and fishing in those areas  

• When anchoring and fishing in other areas, check your anchor, anchor chain and gear for seaweed before you move on. If you find seaweed, remove it, bag it if you can and dispose of it safely to the rubbish on land. If you can’t do this, return it to the waters it came from.  

• If you think you see exotic caulerpa, note the location, take a photo and report it to Biosecurity New Zealand on 0800 80 99 66 or online at report.mpi.govt.nz

This species is known to be in the following locations in Auckland / Waikato Hauraki Gulf; Coromandel; Bay of Islands (Northland). If you find it outside this area, please report it.

Aotea / Great Barrier Island; Rākino, Kawau, Repanga / Cuvier, Mokohīnau Islands; Fantail Bay (Coromandel); Waiheke Island; Te Rāwhiti Inlet; Omākiwi Cove; Motukiekie–Waewaetorea–Moturua Islands; Poroporo Island; Mohenoititi Islands (incl. Hauai); Paradise Bay; Otiao Bay; Cable Bay; Waewaetorea Channel; Sunset Bay; Paroa Bay

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