Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

A preliminary estimate of the contribution of coastal blue carbon to climate change mitigation in New Zealand.

Author
Finnley W. R. Ross, Dana E. Clark, Olga Albot, Anna Berthelsen, Richard Bulmer, Josie Crawshaw, and Peter I. Macreadie
Year
2024
Journal / Source
New Zealand Journal of Marine and Freshwater Research
Volume
58
Number
3
Pages
530-540
Summary
The scale at which New Zealand is currently storing and sequesteringblue carbon, and could create additional blue carbon via restoration,has been unclear. Here, we calculate a preliminary estimate for thecurrent extent of three key blue carbon ecosystems (saltmarshes,mangrove forests and seagrass meadows), their carbon stocks andtheir carbon sequestration rates using the best available data toprovide a preliminary estimate of blue carbon in New Zealand. W ealso use local examples to explore opportunities to createadditional blue carbon. Based on the available literature, we estimate the current extent of New Zealand’s blue carbonecosystems to be 76,152 ha, which is 1.0% of the area of terrestrial native forests. Our preliminary estimate of New Zealand’s blue carbon stock is 2.66–3.76 Mt of carbon, with a current carbon sequestration rate of 0.12 (0.05–0.26) Mt/CO2/yr, which is equivalent to 0.16% of New Zealand’s 2021 gross emissions. Restoration of saltmarshes could enhance their carbon sink capacity, mangrove forests are naturally expanding and seagrass meadow restoration techniques at scale are still in development. Developing a national framework for blue carbon protection, monitoring and restoration is important as part of New Zealand’s climate change mitigation and adaptation effort