Client: Ngāti Paoa (on behalf of the Pou Rāhui Project iwi)
Responding to a National Marine Biosecurity Threat: The Caulerpa Business Case
In 2021, the invasive seaweed Caulerpa was discovered at Aotea/Great Barrier Island – the first detection of this aggressive marine pest in New Zealand waters. By 2023, it had spread to multiple locations across the upper North Island, threatening native marine ecosystems, recreational areas, and culturally significant māhinga kai sites. The seaweed forms dense mats that smother native species and can permanently alter marine habitats, with potentially devastating impacts on coastal environments and local economies.
Iwi partners from the Pou Rāhui Project (Ngāti Paoa, Ngāti Hei, Ngāi Tai Ki Tāmaki, Ngāti Tamaterā) joined forces with Northland Regional Council, Auckland Council, and Waikato Regional Council to tackle this threat. Together, they commissioned MartinJenkins to develop an indicative business case for substantial investment in Caulerpa response efforts.
Using Treasury's Better Business Case framework, we united diverse stakeholders under a cohesive strategy. Our team worked closely with iwi, leading scientific experts, and representatives from central and local government agencies.Within an ambitious four-month timeframe, we developed funding options for a comprehensive national marine biosecurity response, ensured proposed solutions were both practical and tactical, leveraging existing government mechanisms, supported a partnership based governance structure that integrated mātauranga Māori with western science, designed and facilitated a community hui to incorporate local perspectives, and engaged NZIER for specialised economic impact modelling based on proven biosecurity methodologies. The collaborative model developed through this process provides a blueprint for addressing future marine biosecurity threats – one that brings together Crown and iwi to work in partnership while delivering practical, evidence-based environmental solutions.
You can read the full business case here.
