Exotic Caulerpa News

A sample graphic from a recent campaign featuring the submarine drone

Marine Monitoring Update

June 2025

The Marine Monitoring panel meets on a three-weekly basis. Staying connected with other efforts around Tikapa Moana Hauraki Gulf and sharing information remains important in the battle against exotic Caulerpa.

In March, April, May and June this year we have contracted ROV surveillance with operated by Logan Marine on the coast around Waiheke with a crew from the community and Ngāti Pāoa ki Waiheke roopū.

An ROV is a Remotely Operated Vehicle - like a submarine drone and is a helpful piece of technology which records real time video of the seafloor. Humans have limited time and range underwater so using technology and tools to search further and more often will help overall. Waiheke Marine Project has, with the support of Auckland Council, MPI, and the Hauraki Gulf Forum been able to add to Ngāti Pāoa and other's mahi in building knowledge around this smothering pest.  Fortunately, no new discoveries have been made and at the time of writing, only the Controlled Area between Palm Beach to Onetangi is known to contain exotic Caulerpa. There has however been a sighting nearby at Rakino Island which is a reminder of the importance of continuing surveillance.

Records of these transects are shared to Pou Rāhui, Ngāti Pāoa Iwi trust as well as Auckland Council for their Community viewer. This is compiled from similar mahi from the wider Hauraki Gulf area. It shows both positive and negative results and is best viewed on a desktop computer rather than a phone – visit marinepests.nz/interactive-caulerpa-map


If you discover a suspected Exotic Caulerpa example, please

  • Take a photo

  • Record the location, date & time - GPS position if possible

  • Phone 0800 80 99 66 (MPI hotline)

  • If you can, place everything in a sealed bag

  • Don’t return it to the sea

  • Check your anchor, chain, windlass and anchor-well

  • Check your fishing gear - hooks, reels, and rods

  • Check your Dive gear, belts, tanks, wetsuits, fins and spear-guns

  • Wash everything on land using a friendly detergent

MPI have produced a video to help identify this seaweed - view it here