The Critical Importance of Restoring Blue Carbon Wetlands

Blue carbon wetlands—mangroves, saltmarshes, and seagrass meadows—represent some of Earth's most valuable yet threatened ecosystems. Their restoration has emerged as an urgent environmental priority, driven by their important role in climate regulation and the remarkable ecosystem benefits they provide to people and the environment.

Climate Change Mitigation Powerhouses

These coastal ecosystems sequester carbon at rates that far exceed terrestrial forests.[1][2] While covering less than 0.2% of total ocean area, they account for approximately 50% of all carbon buried in ocean sediments.[3][4] Unlike terrestrial systems that primarily store carbon in biomass, blue carbon wetlands lock carbon within their soils for centuries to millennia if left undisturbed.[5][6] Studies suggest that a healthy mangrove forest can sequester nearly five times the carbon of a mature tropical rainforest per unit area.[7] Even more remarkably, these ecosystems continue accumulating carbon indefinitely as sediments build up, rather than reaching carbon saturation as terrestrial forests eventually do.[8]

Coastal Protection and Disaster Risk Reduction

As climate change drives sea level rise and intensifies storm systems, blue carbon wetlands provide irreplaceable natural infrastructure in protecting coastlines, being able to reduce wave heights by up to 66% across just 100 meters of forest width.[9] Saltmarshes also act to absorb storm surge energy and mitigate coastal flooding, while the extensive root systems of all these ecosystems help to stabilise shorelines against erosion. These natural buffers represent cost-effective alternatives to expensive engineered solutions like breakwaters and revetments.

Biodiversity Sanctuaries

Blue carbon wetlands support extraordinary biodiversity, serving as nurseries and habitat for thousands of species. An estimated 80% of global fish catches are directly or indirectly dependent on mangroves,[10] and they are estimated to support 700 billion juvenile fish and invertebrates annually.[11] In the face of climate change and increasing pressures on natural environments, preserving and restoring these biodiversity hotspots is increasingly crucial for maintaining ecological balance and resilience.

Water Quality Enhancement

These ecosystems function as nature's water treatment facilities. Their complex root systems and associated microbial communities filter pollutants, excess nutrients, and suspended sediments. This natural filtration improves water clarity, reduces harmful algal blooms, and supports adjacent ecosystems like coral reefs that depend on good water quality.

Economic Benefits and Livelihoods

The ecosystem services provided by healthy blue carbon wetlands translate to substantial economic value. Globally, these services are worth up to an estimated ~AUD$300,000 per hectare annually [12] when accounting for fisheries support, tourism, carbon sequestration, and coastal protection.[13] For coastal communities, particularly in developing regions, these ecosystems directly support livelihoods through sustainable fishing, eco-tourism, and the harvesting of food, medicine, and building materials. Restoration initiatives often create employment opportunities and strengthen local economies while building climate resilience.

Urgency of Restoration

Despite their immense value, we continue losing these ecosystems at alarming rates—approximately 1-2% annually worldwide.[14] This loss represents not only foregone future benefits but also releases previously stored carbon as these systems degrade. The good news is that restoration techniques have advanced significantly, with successful projects demonstrating that with proper methods and community involvement, we can revive these ecosystems and their services.

Opportunities for low-lying land and lost wetlands

The targeted restoration of lost wetlands and low-lying coastal land provides specific opportunities for strategic land use change in areas that are unproductive (e.g., for traditional land uses like dryland agriculture), poorly drained, and subject to risk due to sea level rise. In restoring these environments in a timely fashion, we can create highly productive and resilient wetlands that can provide habitat for many species, help to address the impacts of climate change and keep pace with sea level rise.[15] [16] 

Restore Blue sits within this niche, helping to reintroduce tidal flows to such areas and supporting the expansion of wetland environments.

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References

[1] McLeod, E., Chmura, G.L., Bouillon, S., Salm, R., Bjork, M., Duarte, C.M., Lovelock, C.E., Schlesinger, W.H. and Silliman, B.R., 2011. A blue print for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO_2. Front. Ecol. Environ., 9(10), p.552-560, doi: 10.1890/110004.

[2] Serrano, O., Lovelock, C.E., B. Atwood, T. et al., 2019. Australian vegetated coastal ecosystems as global hotspots for climate change mitigation. Nat Commun, 10, doi: 10.1038/s41467-019-12176-8.

[3] Serrano, O., Lovelock, C.E., B. Atwood, T. et al., 2019. Australian vegetated coastal ecosystems as global hotspots for climate change mitigation. Nat Commun, 10, doi: 10.1038/s41467-019-12176-8.

[4] Duarte, C. M., Middelburg, J.J., and Caraco, N. 2005. Major role of marine vegetation on the oceanic carbon cycle. Biogeosciences. 2, doi: 10.5194/bg-2-1-2005.

[5] Mitsch, W.J., Bernal, B., Nahlik, A.M., Mander, U., Zhang, L., Anderson, C.J., Jørgensen, S.E., and Brix, H., 2013. Wetlands, carbon, and climate change. Landscape Ecol, 28, p.583–597, doi: 10.1007/s10980-012-9758-8.

[6] Kelleway, J.J., Saintilan, N., Macreadie, P.I., Baldock, J.A., Heijnis, H.,  Zawadzki, A., Gadd, P., Jacobsen, G., and Ralph, P.J., 2017. Geochemical analyses reveal the importance of environmental history for blue carbon sequestration, J. Geophys. Res. Biogeosci., 122, doi: 10.1002/2017JG003775.

[7] Donato, D.C., Kauffman, J.B., Murdiyarso, D., Kurnianto, S., Stidham, M., and Kanninen, M., 2011. Mangroves among the most carbon-rich forests in the tropics. Nature Geoscience, 4, p.293-297, doi:10.1038/ngeo1123.

[8] McLeod, E., Chmura, G.L., Bouillon, S., Salm, R., Bjork, M., Duarte, C.M., Lovelock, C.E., Schlesinger, W.H. and Silliman, B.R., 2011. A blue print for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO_2. Front. Ecol. Environ., 9(10), p.552-560, doi: 10.1890/110004.

[9] Spalding, M., McIvor, A., Tonneijck, F., Tol, S., and van Eijk, P., 2014. Mangroves for coastal defense. Guidelines for coastal managers and policy makers. Wetlands International, University and Cambridge and The Nature Conservancy.

[10] Sandilyan, S., and Kathiresan, K., 2012. Mangrove conservation: a global perspective. Biodiversity Conservation, 21, p.3523–3542, doi:10.1007/s10531-012-0388-x.

[11] zu Ermgassen, P.S.E., Worthington, T.A., Gair, J.R. et al., 2025. Mangroves support an estimated annual abundance of over 700 billion juvenile fish and invertebrates. Commun Earth Environ, 6, doi:10.1038/s43247-025-02229-w.

[12] Original figure of USD 200,000 adjusted for purchasing power parity.

[13] de Groot, R., Brander, L., van der Ploeg, S., Costanza, R., Bernard, F., Braat, L., Christie, M., Crossman, N., Ghermandi, A., Hein, L., Hussain, S., Kumar, P., McVittie, A., Portela, R., Rodriguez, L.C., ten Brink, P., and van Beukering, P., 2012. Global estimates of the value of ecosystems and their services in monetary units. Ecosystem Services, 1(1), p.50-61, doi:10.1016/j.ecoser.2012.07.005.

[14] Convention on Wetlands 2021. Global Wetland Outlook: Special Edition 2021. Gland, Switzerland: Secretariat of the Convention on Wetlands.

[15] Duarte, C.M., Losada, I.J., Hendriks, I.E., Mazarrasa, I., and Marbà, N., 2013. The role of coastal plant communities for climate change mitigation and adaptation. Nature Climate Change, 3, p.961-968, doi:10.1038/nclimate1970.

[16] Glamore, W., Rayner, D., Ruprecht, J., Sadat-Noori, M., and Khojasteh D., 2021. Eco-hydrology as a driver for tidal restoration: Observations from a Ramsar wetland in eastern Australia. PLOS ONE, 16(8), doi: 10.1371/journal.pone.0254701.