Caulerpa
Common name: Exotic Caulerpa
Scientific name: Caulerpa bracypus, Caulerpa parvifolia
Management programme: Exclusion
Where is it originally from?
Exotic caulerpa is the collective name given to two, near-identical species of introduced caulerpa. They have a wide native range spanning across the Indo-Pacific region from Africa to Australia, the Pacific Islands and southern Japan.
Why is it a pest?
- Exotic caulerpa forms dense carpets that smother the seafloor, crowding out native shellfish, seagrass and seaweed species.
- It disrupts natural ecosystems and food-chains while colonising fish nurseries and inhibiting the growth of fish.
Where is it found?
- Exotic caulerpa can grow on most ocean surfaces from 2-35m deep.
- It has not been found in the Bay of Plenty, but it has established itself in other areas of New Zealand, including parts of the Hauraki Gulf, Coromandel Peninsula, Aotea (Great Barrier Island), Ahuahu (Great Mercury Island) and the Bay of Islands.
What does it look like?
- Exotic caulerpa is bright green with round, oar-shaped blades that grow up to 10cm long.
- The oar-shaped blades are attached to a long root or runner called a stolon.
How to prevent the spread of exotic caulerpa
Exotic caulerpa reproduces through fragments breaking off. It can easily get snagged on anchors, anchor chains, and diving and fishing gear, and be transported to new locations, which then create new infestations.
- Before leaving your location out at sea, check your vessel’s anchor and anchor chain, as well as any other gear that has been in the water, for any fragments of weed.
- If you find any type of seaweed on your gear, bag it and bin it, and take it back to shore for disposal.
What are the rules?
Exclusion
Exclusion pests are not known to be present and/ or established in the Bay of Plenty region. The Regional Council is responsible for managing new incursions into the region. Action may be required from landowners or occupiers to support a control operation.
Controlled Area Notices
Biosecurity rules are in place to stop the spread of exotic caulerpa through a mechanism under the Biosecurity Act called a Controlled Area Notice (CAN). There are restrictions on some anchoring and fishing activities in four locations:
- Aotea (Great Barrier Island)
- Ahuahu (Great Mercury Island)
- Te Rāwhiti inlet in the Bay of Islands
- Waiheke Island
As new infestations are found, the rules regarding CANs evolve.
For up-to-date information, please visit the MPI website.
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