Tag: blue carbon

Peer-reviewed Publications

Marx et al. (2026): The Ecological Activity Index tool for mapping potential ecosystem exposure to ocean alkalinity enhancement

Lukas Marx, Jennie E. Rheuban, Daniel C. McCorkle, Christopher S. Murray, Yiming Guo, Zhaohui Aleck Wang, Anna P. M. Michel, Ke Chen, Heather H. Kim and Adam V. Subhas, IN: Communications Sustainability, https://doi.org/10.1038/s44458-026-00123-w

Ocean alkalinity enhancement is being explored to remove carbon dioxide from the atmosphere, but its interactions with marine ecosystems remain uncertain. Robust data-based baseline frameworks are needed to assess where and when ecosystems may be increasingly exposed to ocean alkalinity enhancement. Here the authors present the Ecological Activity Index (EAI) that integrates publicly available datasets on chlorophyll a, zooplankton, and fish larvae abundance, endangered species distributions and commercial fishing activity across the United States Northeast Shelf and Slope. This framework provides a spatially and temporally resolved measure of ecosystem activity and human use.

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Peer-reviewed Publications

Hilmi et al. (2026): Global assessment shows blue carbon wealth dominated by ocean processes and unevenly distributed across countries

Nathalie Hilmi, Loua Aurel De Vince Vehi, Marina Treskova, Cécile Sabourault and Lisa Levin, IN: Communications Sustainability, https://doi.org/10.1038/s44458-026-00117-8

Marine ecosystems remove carbon dioxide from the atmosphere and regulate climate, yet their contribution remains weakly represented in national wealth accounts. Here the authors develop a global valuation framework for blue carbon wealth that combines spatial data on coastal ecosystems, including mangroves, seagrasses and salt marshes, with country-level estimates of open-ocean biological carbon transport. They value annual removal flows using country-level social cost of carbon estimates.

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Peer-reviewed Publications

Ward et al. (2026): Blue Carbon in an Era of Carbon Accounting

M. Ward, M.T. Costa, A.M. Ricart, S. Crooks, L.M. Wedding and P.I. Macreadie, IN: Annual Review of Environment and Resources, https://doi.org/10.1146/annurev-environ-121522-043142

Blue carbon ecosystems—mangroves, tidal marshes, seagrass meadows, and, increasingly, seaweeds—are being rapidly integrated into climate mitigation frameworks. Yet, despite their prominence in global carbon offset discourse, blue carbon projects remain dominated by mangroves (∼89% of projects). Here, the authors synthesize recent developments in blue carbon science, carbon accounting, and market integrity. Global restoration potential could deliver annual removals of ∼109 (98–119; 95% CI) million tonnes of organic carbon, while habitat loss causes annual emissions of up to ∼63 (55–71) million tonnes. Realizing carbon benefits is constrained by monitoring, reporting, and verification costs, data gaps, and methodological challenges.

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Peer-reviewed Publications

Hao et al. (2026): Harnessing the Microbial Carbon Pump: Prospects and Challenges for Coastal Carbon Sequestration

Jinzi Hao, Yue Sun, Xiaodi Shang, Boyuan Wang, Hailong Huang, Anran Wang, Xiaohan Yang, Lei Jie and Jinhui Sun, IN: Frontiers in Marine Science, https://doi.org/10.3389/fmars.2026.1897665

The Marine Microbial Carbon Pump (MCP) theory proposes a novel mechanism for long-term carbon sequestration in the ocean, wherein microbial processes convert labile dissolved organic carbon (LDOC) into recalcitrant dissolved organic carbon (RDOC). This review synthesizes recent advancements in technologies aimed at enhancing carbon sinks based on the MCP, with a specific emphasis on coastal ecosystems. Through a structured literature review, the authors evaluate the mechanisms of action, key environmental regulatory factors, and negative emissions technologies associated with utilizing the MCP to bolster the ocean carbon sink.

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Peer-reviewed Publications

Mengistu et al. (2026): Ethiopia’s green legacy initiative enhances carbon stock and carbon dioxide sequestration across diverse landscapes

Dejene K. Mengistu, Hailu Terefe, Basazen F. Lakew, Abiyou Tilahun and Bogale N. Hailemariam, IN: Scientific Reports, https://doi.org/10.1038/s41598-026-61968-8

Ethiopia’s Green Legacy Initiative (GLI) is one of the world’s largest landscape restoration programs, yet its contribution to carbon sequestration across diverse land uses and agroecological zones remains poorly quantified. This study assessed the effects of GLI interventions on biomass accumulation, carbon storage (CS), and carbon dioxide equivalent (CO₂e) sequestration across 21 districts representing major implementation regions of Ethiopia. A total of 8,209 plants belonging to 90 species and 42 families were measured across four land-use types and eight management practices. Aboveground biomass, carbon stock, and CO₂e sequestration were estimated using species-appropriate allometric equations.

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Peer-reviewed Publications

Natividad et al. (2026): Organic–inorganic carbon coupling shapes carbon dioxide fluxes in seagrass ecosystems

Mariche B. Natividad, Wei-Jun Cai, Nina Bednaršek, Jian-Jhih Chen and Wen-Chen Chou, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-026-03805-4

Seagrass meadows can remove atmospheric carbon dioxide through organic carbon production and storage, but they also alter seawater chemistry through calcium carbonate formation and dissolution. Most blue carbon assessments focus on organic carbon burial and overlook how inorganic carbon cycling regulates carbon dioxide exchange. This Perspective presents a framework linking organic carbon metabolism, carbonate cycling, and sedimentary processes to explain when seagrass ecosystems function as net carbon dioxide sinks or sources. The authors introduce a compensation ratio that defines the balance between organic carbon uptake and calcification-driven carbon dioxide release and show how this balance changes with environmental conditions and sediment carbon sources. Using the Dongsha Island lagoon as a case study, the authors show how seagrass metabolism coupled to dissolution of geologically derived carbonate sediments can sustain alkalinity generation and long-term carbon dioxide uptake. Together, this framework provides a more complete basis for evaluating blue carbon and the climate mitigation potential of carbonate-rich coastal ecosystems.

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Peer-reviewed Publications

Van Dam (2026): Parameterizing air–sea CO₂ transfer in a macroalgal habitat and assessing its role in marine carbon dioxide removal accounting

Bryce Van Dam, IN: Limnology and Oceanography Letters, https://doi.org/10.1002/lol2.70139

Accurately quantifying air–sea CO₂ exchange remains a central challenge for the measurement, reporting, and verification (MRV) of marine carbon dioxide removal. The author applies direct eddy covariance measurements of CO₂ fluxes at a macroalgae-dominated coast to compile the first gas transfer velocity (k660) parameterization for such a habitat. k660 exhibited a quadratic dependence on wind speed of the form: 𝑘660 =0.183 ×𝑈102 +2.17.

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Peer-reviewed Publications

Borbhuyan et al. (2026): Wetland Type Matters: Tree Community Structure and Carbon Sequestration Dynamics Along a Tropical River Basin

Samim Borbhuyan, Nirjhar Das, Kasturi Chakraborty, Kamini Kanta Sarma, Dibyendu Adhikari and Tapati Das, IN:Environmental Management, https://doi.org/10.1007/s00267-026-02496-z

Wetlands are among the most productive and ecologically significant ecosystems on the earth, offering a broad spectrum of ecosystem services including water purification, flood regulation, habitat provision, and climate regulation. In light of current global climate challenges, their capacity for carbon storage has become increasingly important, positioning wetlands as key components in climate change mitigation strategies. This study attempts a comprehensive understanding of the contributions of different types of tropical wetlands to ecological diversity and carbon dynamics. The findings of this study aim to inform climate action, support conservation planning, and strengthen local livelihoods. In the longer term, the study underscores the importance of tropical wetlands in regional and global carbon cycling, with clear relevance for wetland conservation and climate policy. For this study, the authors selected three morphologically and hydrologically distinct wetlands, namely, Fulbari Anua (oxbow lake, OL), Bakri Haor (floodplain wetland, FPW), and Sone Beel (perennial wetland, PW) in the Barak basin of Assam, northeast India, within the Indo-Burma biodiversity hotspot. Tree individuals were randomly sampled from both the aquatic zone (permanently inundated areas) and the riparian zone (seasonally flooded margins) of the selected wetlands. Comparison of the tree community composition across different wetland types revealed a total of 30 tree species representing 18 families.

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Peer-reviewed Publications

Zhou et al. (2026): Unravelling saltmarsh organic carbon sources: biomarker-isotopic integration for credible blue carbon accounting

Jinge Zhou, Hua He, Han Chen, Jingfan Zhang, Zhe Lu et al., IN: CATENA, https://doi.org/10.1016/j.catena.2026.110344

Saltmarshes are vital coastal blue carbon (C) ecosystems (BCEs) that store large amounts of organic C (OC) in sediments. This OC originates from both local (autochthonous) and external (allochthonous) marine or terrestrial sources. Accurately quantifying these OC sources is crucial for effectively allocating blue C credits. In this study, the authors investigated the sources of sedimentary organic carbon (SOC) in two representative Chinese saltmarshes, each characterized by distinct vegetation communities (Spartina alterniflora, Suaeda salsa, and Phragmites australis). By integrating n-alkane signatures (plant sources) and amino sugars (microbial necromass) with δ¹³C-N/C analysis, they quantify five distinct OC sources: autochthonous plant-derived halophytes OC, allochthonous terrestrial xylophyta OC, and allochthonous marine algae OC, as well as microbial-derived fungal necromass C, and bacterial necromass C.

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Peer-reviewed Publications

Rischer et al. (2026): An ecosystem of carbon dioxide removal reviews – part 2: CO₂ removal via blue carbon ecosystems

Christian Rischer, Ignacio Saldivia Gonzatti, Daniel A. Friess, Patricia Grasse, David Keller, Johannes R. Krause, Sarah Lück, Carisa MacPherson, Jennifer McHenry, Christine Merk, Tiffany Troxler, Rudi Voss and Wilfried Rickels, IN: Energy & Environmental Science, https://doi.org/10.1039/D5EE04922A

Carbon dioxide removal (CDR) is essential for achieving global climate goals, such as those outlined in the Paris Agreement. This systematic review investigates the current state of CDR through management pathways for blue carbon ecosystems (BCEs) and assesses their role in the global CDR portfolio. This article analyzed 2622 peer-reviewed and gray literature articles out of 13 859 identified using a machine learning-assisted review process published through November 2025. The review focuses primarily on mangroves, seagrass meadows, salt marshes, and macroalgae.

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