Current removal technology projects
3 projects are underway to develop and trial methods to control exotic Caulerpa using an additional $10 million funding announced in August 2024.
Media release: Further funding boost for second phase in exotic caulerpa battle – Beehive
Northland Regional Council has been awarded the largest contract, with just over $6 million to progress earlier work on a large-scale mechanical suction dredging technique that was trialled in Omakiwi Cove in 2024.
The first phase of the work demonstrated that the method can remove exotic caulerpa from sandy areas of the seafloor, and the next phase is to increase its effectiveness.
The project team is developing a new tool called a 'submersible dredge planer' which will operate remotely on the seafloor, rather than from a barge, and aims to remove caulerpa in a single pass.
The new system will include a dredge head, pumping arrangement, global positioning system (GPS), dredge spoil processing plant, and disposal system.
The second project, receiving $2 million in funding, is developing an ultra-violet light (UV-C) irradiation tool to kill the pest seaweed.
This contract has been awarded to Advanced Aquarium Technologies Ltd who aim to create a cost-effective option to treat exotic invasive caulerpa without needing to deploy SCUBA divers.
The third project, with $1.9 million funding, is a special underwater treatment 'chamber' to contain chlorine to a specific treatment area. The device, being developed by Commercial Dive Specialists, will be able to hover over the seabed and pass over rocks and other obstacles without getting stuck.
Media release: Multi-million-dollar exotic Caulerpa control tool projects underway – Beehive
The 3 projects build on work carried out under an accelerated programme funded in 2024.
2024 accelerated programme to fight exotic caulerpa
Following a $5 million funding boost announced in February 2024, 6 projects were set up to accelerate work on removal technologies and improved surveillance.
Media release: Government boost to fight against caulerpa – Beehive
At Omakiwi Cove in the Bay of Islands, Northland Regional Council and mana whenua (funded by MPI) carried out the flagship project to develop a large-scale suction dredge to remove exotic caulerpa at a large-scale from the seafloor.
The project achieved some significant advances, including creating equipment to remove sand from the dredged caulerpa. Further work was required to achieve faster and more effective removal.
At the Iris Shoal off Kawau Island, a partnership between Ngāti Manuhiri and National Institute of Water and Atmospheric Research (NIWA) used a smaller-scale suction technique where divers hand-controlled a portable vacuum device. The team managed to remove exotic caulerpa from 1.27 hectares of the seabed and safely dispose of the material at a local landfill.
Other accelerated programme projects
- Managing caulerpa in key areas at Aotea to push back the "creeping" expansion there, and help prevent spread to other areas.
- Resurvey the incursion at Ahuahu Great Mercury Island to better understand the population there and inform a possible future suppression or elimination effort.
- Operational research to improve surveillance techniques to locate new areas of exotic caulerpa – being trialled at Waiheke Island. This project saw the successful development of cameras mounted on towed and remote-operated vehicles to find exotic caulerpa and identify it as caulerpa at the same time using artificial intelligence.
Research and technical reports into exotic caulerpa and work of the Exotic Caulerpa National Advisory Group
Reports from the accelerated programme projects and minutes of national advisory group meetings will be posted here when finalised.
