In a paper published last year led by our Founder Finn Ross in the New Zealand Journal of Marine and Freshwater Research scientists estimated the potential of New Zealand to sequester coastal or blue carbon. We have been asked a lot lately about Blue Carbon in New Zealand so thought we would summarise the state of play here.
There has been a tremendous recent upsurge in interest from the government, private sector, and the general public about the potential for blue carbon in New Zealand. New Zealand has the 4th largest ocean space in the world with a massive coastline and we pride ourselves on sustainability credentials.
It is estimated the current extent of New Zealand’s coastal blue carbon ecosystems (mangroves, saltmarshes, and seagrasses) is 76,000 ha, which is 1.0% of the area of terrestrial native forests. The New Zealand blue carbon stock is 2.6 - 3.7 Mt of carbon, with a current carbon sequestration rate of 120,000 t/CO2/yr, which is equivalent to 0.16% of New Zealand's 2021 gross emissions.
Restoration of saltmarshes by rewetting coastal areas that were historically drained is the most actionable Blue Carbon restoration opportunity in New Zealand and we should invest in salt marsh restoration immediately. Mangrove forests are limited to the northern part of the North Island and are naturally expanding due to increased sediment runoff. And Seagrass meadow restoration techniques at scale are still in development and more funding is needed. Overall Developing a national framework for blue carbon protection, monitoring, and restoration is an important next step as part of New Zealand's climate change mitigation and adaptation efforts.
We support the recent proposal for the development of an Aotearoa Marine Carbon Forum. While these estimates only focused on coastal blue carbon, we have more to say on seaweed and geoengineering blue carbon in coming posts.
