Marine Pests

Exotic Caulerpa

Two non-native invasive seaweeds (exotic caulerpa) have been found in waters at Aotea Great Barrier Island,
Ahuahu Great Mercury Island, Te Rāwhiti Inlet in the Bay of Islands, off Kawau Island and at Waiheke Island.

These unwanted organisms can spread rapidly, forming dense beds and potentially smothering native species.
Legal controls and rāhui are in place at some of these locations to stop the spread, so if you are heading out to these areas make sure you check the rules at

You can also find maps showing the exact locations of caulerpa and it is good practice to avoid
these areas altogether.
Keeping your boat and equipment clean is the best thing you can do to avoid spreading marine pests,
including caulerpa.

With caulerpa in particular:

When out on the water, before you move on, check your anchor and chain when you pull it up.
Also check fishing or diving equipment for any attached seaweed.

If you find any seaweed on your gear, remove it and bag it or contain it securely, and take it ashore
for disposal in a rubbish bin. If you can't do this (bag it and bin it safely) - put it back into the waters
it came from.
That means any seaweed - it's good practice and you don't have to be an expert in identifying caulerpa.
Together let's stop the spread of exotic caulerpa.

If you 'See Weed', Bag it, Bin it.

Pest and Disease Hotline 0800 80 99 66
Report Pest online here | See the New! marine pest map

Send an Enquiry