Exotic caulerpa is causing headaches for authorities.
Exotic caulerpa is causing headaches for authorities.
Concerns have been raised that work being supported by central government is not sufficiently coordinated, focused, and operating with the urgency warranted to manage invasive caulerpa and its wider ranging negative impacts.
Hauraki District Council has raised a red flag as it considers contributing $10,000 towards a $400,000 Ngāti Paoa Iwi Trust exotic caulerpa better business case proposal.
A report to be tabled at a council meeting on August 28 said the council, alongside other territorial authorities and iwi representatives, was invited to engage in conversations around a better business case to provide central government with a national programme to eliminate caulerpa.
This was due to the concern that “current work being supported by central government was not sufficiently coordinated, focused, and operating with the urgency that was warranted to manage it and the wider ranging negative impacts”.
Caulerpa are a group of single-celled macroalgae set apart by their green photosynthetic fronds, which grow up to 10cm long in the shape of oar blades that rise from long runners or roots, known as stolons.
New Zealand happens to be home to nine native species of this seaweed, but it’s two exotic species, naturally found in the Indo-Pacific region, that have been causing headaches since they were first detected in NZ waters three years ago.
Confirmations of contribution towards the $400,000 required had so far been received from five iwi, Auckland Council, Northland Regional Council, Waikato Regional Council and Thames Coromandel District Council.
Philanthropic funding had also been confirmed from Foundation North and the Tindall Foundation, while Whakatupu Aotearoa Foundation had been engaged for funding.
New Zealand’s first mechanical caulerpa suction dredge in action in Omākiwi in the Bay of Islands Photo / Susan Botting
It was recommended it would be appropriate for the council to consider a financial contribution of up to $10,000.
Ngāti Paoa had recently proposed, and the Pou Rāhui iwi were looking to take the initiative of commissioning the business case to provide central Government with a national programme to eliminate caulerpa.
It would look to assess the cost of damage to the marine environment by caulerpa, should it become widely established, against the cost of an “at pace and scale” programme of elimination, and to undertake political engagement with central government to fund the latter.
The timeline for the business case included establishment of conversations in July, in September work on a case for change, in October present emerging options, and in November, a final business case that would be delivered to the Ministry for Primary Industries to inform possible budget bids.
An action plan would be provided by the consultancy in the coming weeks, which would include key workshops and other important dates, the report said.
A letter had also been drafted and sent to the Minister for Biosecurity outlining the reasoning behind why the indicative business case initiative was being taken.
“The intention of the business case is not to compete against current work being conducted in this space, but to work collectively to compliment those work programmes,” the report said.
“Members noted the need to keep conversations active and continue to advocate to government at all levels.”
Caulerpa is an exotic weed that upsets ecosystem balance.
Since the middle of 2023, the Ngāti Paoa Iwi Trust had been involved in trying to develop tools to manage and ideally eliminate caulerpa, including trialling biodegradable woollen benthic mats.
Ngāti Paoa was also one of five iwi (along with Ngāi Tai ki Tāmaki, Ngāti Hei, Ngāti Rehua Ngātiwai ki Aotea and Ngāti Tamaterā), participating in the Pou Rāhui project, a multi-year endeavour fund project focused on marine restoration and learning-by-doing.
This year, Biosecurity NZ concluded it would not be feasible to eradicate caulerpa from New Zealand, advising long-term management primarily through containment, suppression and local elimination.
Biosecurity NZ has established the National Caulerpa Advisory Group to provide advice to guide ongoing management of caulerpa through development of a national strategy and support a more integrated, coordinated to ongoing caulerpa management.
The report said there had been a significant threat posed by caulerpa to the marine environment since 2021.
Over time, the group had focused on five possible strategies: Do nothing, containment, suppression, local elimination and eradication.
