Blue Carbon Research Articles

Seas the opportunity: multi-criteria decision analysis to identify and prioritise blue carbon wetland restoration sites

IntroductionThe emergence of voluntary carbon markets is creating new opportunities to sustainably finance Natural Climate Solution (NCS) projects. In Australia, the federal government recently enacted the Tidal Restoration of Blue Carbon Ecosystems Methodology Determination 2022 (Tidal Reconnection Method), whereby restoration activities that reintroduce tidal flows to allow the re-establishment of coastal wetland (blue carbon) ecosystems, through the removal or modification of a tidal restriction, can be used to gain and sell Australian carbon credit units. Australia has the highest net blue carbon wealth in the world, with 5%–11% of global carbon stocks, yet there is currently a lack of large-scale feasibility assessments and supporting methodologies to identify and prioritise sites with the greatest potential for NCS project implementation to help inform investment decisions.MethodsIn this study, we applied a spatial Multi-Criteria Decision Analysis (MCDA) to identify, map, and prioritise potential sites for blue carbon coastal wetland restoration in South Australia that meet criteria outlined in the Tidal Reconnection Method. This study compared information on 1) predicted flooding extent following tidal reconnection and under sea level rise (SLR; present-day, 2050 and 2,100); 2) project implementation complexity (e.g. who possesses land tenure); and 3) carbon sequestration potential through predicted area of vegetation change under the above SLR scenarios. ResultsOur results identified 64 sites of interest, of which 32 received an overall “high” prioritisation score of 3 or more out of 5. This equates to approximately 21,114 ha of high priority potential blue carbon restoration sites.DiscussionThe MCDA enables development of a portfolio of viable restoration projects through a rapid “desktop” prioritisation of sites of interest, which can then guide investment in further detailed cost/benefit feasibility assessments. This study demonstrates an adaptable MCDA approach to map potential NCS projects at meaningful spatial scales and in-line with carbon market-based opportunities.

Blue Carbon as a Nature-Based Mitigation Solution in Temperate Zones

Concern for the future requires local steward-led cooperation between natural and social scientists and decision-makers to develop informed and policy-relevant nature-based mitigation solutions, including blue carbon (BC), which can help secure the future. Salt marshes, kelp forests, and seagrass meadows (and to a lesser extent mangroves) are significant BC ecosystems in temperate areas. We discuss the concept of blue carbon stocks and the scientific approaches to building BC stocks considering the variability in local conditions and the co-benefits of blue carbon ecosystems to improve climate change mitigation and adaptation mechanisms. The study examines (1) methods to assess the potential of BC ecosystems and the impact of disturbances, while (2) building relevant policy based on socio-economic assessments of impacted communities. We highlight economic and social approaches to rebuilding BC using financial tools such as blue bonds, development plans, cost-benefit analyses, cross-ecosystem restoration projects, AI and blockchain, and economic accounts of coastal ecosystems, while emphasizing that cutting carbon emissions is more important than (re)building BC stocks.

A Study on Classification of Halophytes-based Blue Carbon Cover and Estimation of Carbon Respiration Using Satellite Imagery - Targeting the Gwangseok-gil Area in Muan-gun, Jeollanam-do -

A Study on Classification of Halophytes-based Blue Carbon Cover and Estimation of Carbon Respiration Using Satellite Imagery - Targeting the Gwangseok-gil Area in Muan-gun, Jeollanam-do -

Analysis of the potential of marine bioblue carbon storage and their regional contributions in Shanghai marine areas

Shanghai's extensive coastline and offshore marine areas feature diverse ecosystems. This study aimed to determine the current status, spatial distribution, and total capacity of marine carbon storage in Shanghai. Surveys were conducted on oyster reefs, phytoplankton, and fish populations from August to November 2022, with samples collected to quantify biomass and carbon content. The carbon storage of oyster reefs, phytoplankton, and fish was found to be 2.045 × 105 tC, 5113.19 kgC, and 56.6014 tC, respectively. The spatial distributions exhibited significant heterogeneity, influenced by substrate type, nutrient concentrations, and fishing activities. The total marine carbon storage capacity in Shanghai's offshore waters was estimated at 2.045 × 105 tC, highlighting a pathway for achieving regional carbon neutrality goals. This study enriches baseline data, elucidates carbon sequestration functions and spatial patterns, and provides scientific support for marine ecological protection and blue carbon resource utilization. Future research should investigate spatiotemporal variation mechanisms and potential regulation pathways.

Mapping the evolution of seawater desalination research (2000–2024): Bibliometric and co-word analysis of 11,000+ publications

Seawater desalination (SWD) can partially mitigate the increasing freshwater needs globally. Although, SWD is multifaceted and involves processes with environmental and economic challenges, research is often analyzed through Literature Reviews (LRs) in specific contexts that may miss general trends. Bibliometric Analyzes (BAs), however, provide researchers with an overview through Co-occurrence Networks (CNs), Strategic Diagrams (SDs), Thematic Subnetworks (TSs), and Thematic Evolution Diagrams (TEDs). Nevertheless, their use in SWD research has been limited, with minimal attention given to them. Thus, we created a bibliometric dataset, compared it with other BAs, and developed CNs, SDs, TSs, and a TED for SWD. Furthermore, key term searches (Energy, Solar, Reverse Osmosis, Modeling and Optimization, Membrane Distillation, Environmental, Economics, Fouling, Nanofiltration, and Ultrafiltration) and their literature are discussed. Geographical analysis shows China and the US lead SWD research, shifting from process design to membrane fabrication and solar energy. Furthermore, RO remains the leading technique despite high energy demands. Solar desalination shows promise but faces cost and scalability challenges. Environmental and economic concerns are discussed, as well as emerging solutions regarding, solar desalination, blue energy, “blue carbon”, and zero liquid discharge. Research gaps include fouling effects and pretreatment incorporation in optimizations are also highlighted.

Fatty acids and stable isotopes distribution in the mangrove dominated Parnaíba River Delta

Characterizing the origin and quality of the organic matter (OM) present in estuaries, as well as its export toward the ocean, is a key issue to better understanding the carbon cycle and its impact on global change. In this study, fatty acid markers and δ13C and δ15N values were used to characterize the particulate and sedimentary organic matter composition in the large mangrove-dominated Parnaíba Delta, known as a large reservoir of blue carbon. The presence of some long-chain fatty acids and other mangrove OM markers, such as the 18:2ω6 and 18:3ω3, indicated that the material produced in mangroves contributed largely to the particulate organic matter of water and sediments of the delta. Their presence in further oceanic stations also reveals the mangrove material is exported to the adjacent coastal ocean. In the main river channel, the higher contribution of 18:2ω6 in the sediments than in the mangrove regions, indicated an additional source related to anthropogenic activities, probably agriculture. The branched fatty acids found in the samples point to the presence of bacteria and indicated the intense modifications of the organic matter in the region, reflecting the heterotrophic nature of the delta. In addition, the predominance of saturated fatty acids in the delta suggests that the organic matter exported to the coastal ocean is dominated by detrital material.

Methylotrophic substrates stimulated higher methane production than competitive substrates in mangrove sediments

Although mangrove forests can uptake atmospheric CO2 and store carbon as organic matter called “blue carbon”, it is also an important natural source of greenhouse gas methane. Methanogens are major contributors to methane and play important roles in the global carbon cycle. However, our understanding of the key microbes and metabolic pathways responsible for methanogenesis under specific substrates in mangrove sediments is still very limited. Here, we set an anaerobic incubation to evaluate the responses of methanogens in mangrove sediments from South China to the addition of diverse methanogenic substrates (H2/CO2, acetate, trimethylamine (TMA), and methanethiol (MT)) and further investigated the dynamics of the whole microbial community. Our results showed that diverse substrates stimulated methanogenic activities at different times. The stimulation of methanogenesis was more pronounced at early and late periods by the addition of methylotrophic substrates TMA and MT, respectively. The amplicon sequencing analysis showed that genus Methanococcoides was mainly responsible for TMA-utilized methanogenesis in mangrove sediment, while the multitrophic Methanococcus was most abundant in H2/CO2 and MT treatments. Apart from that, the bacteria enrichments of Syntrophotalea, Clostridium_sensu_stricto_12, Fusibacter in MT treatments might also be associated with the stimulation of methane production. In addition, the metagenomic analysis suggested that Methanosarcinaceae was also one of the key methanogens in MT treatments with different genomic information compared to that in TMA treatments. Finally, the total relative abundances of methanogenesis-related genes were also highest in TMA and MT treatments. These results will help advance our understanding of the contributions of different methanogenesis pathways and methanogens to methane emissions in mangrove sediments.

The hidden acceleration pump uncovers the role of shellfish in oceanic carbon sequestration

Whether shellfish mariculture should be included in the blue carbon profile as a strategy to combat climate change has been controversial. It is highly demanding not only to provide calibration quantitation, but also to provide an ecosystem-based mechanism. In this study, we chose mussel farms as a case study to evaluate their contributions to carbon sinks and their responses to sedimentary carbon fixation and sequestration. First, we quantified the air–sea CO2 flux in the mussel aquacultural zone and observed a weak carbon sink (−0.15 ± 0.07 mmol·m−2·d−1) during spring. Next, by analyzing the carbon composition in the sediment, we recorded a noticeable and unexpected increase in the sedimentary recalcitrant carbon (RC) content in the mussel farming case. To address this surprising sedimentary phenomenon, a long-term indoor experimental test was conducted to distinguish the consequences of mussel engagement with sedimentary RC. Our observational data support the idea that mussel engagement promotes accumulation of RC in sediments by 2.5-fold. Furthermore, the relative intensity of carboxylic-rich alicyclic molecule (CRAM)-like compounds (recalcitrant dissolved organic matter (RDOM)) increased by 451.4 % in the mussel-engaged sedimentary dissolved organic matter (DOM) in comparison to the initial state. Mussel engagement had a significantly positive effect on the abundance of sedimentary carbon-fixing genes. Therefore, we definitively conclude that mussel farming is blue carbon positive and propose a new alternative theory that mussel farming areas may have high carbon sequestration potential via an ecologically integrated “3 M” (microalgae–mussel–microbiota) consortium. The “mussel pump” accelerates carbon sequestration and enhances climate-related ecosystem services.

Enhancing Magnetic Micro- and Nanoparticle Separation with a Cost-Effective Microfluidic Device Fabricated by Laser Ablation of PMMA.

Superparamagnetic iron oxide micro- and nanoparticles have significant applications in biomedical and chemical engineering. This study presents the development and evaluation of a novel low-cost microfluidic device for the purification and hyperconcentration of these magnetic particles. The device, fabricated using laser ablation of polymethyl methacrylate (PMMA), leverages precise control over fluid dynamics to efficiently separate magnetic particles from non-magnetic ones. We assessed the device's performance through Multiphysics simulations and empirical tests, focusing on the separation of magnetite nanoparticles from blue carbon dots and magnetite microparticles from polystyrene microparticles at various total flow rates (TFRs). For nanoparticle separation, the device achieved a recall of up to 93.3 ± 4% and a precision of 95.9 ± 1.2% at an optimal TFR of 2 mL/h, significantly outperforming previous models, which only achieved a 50% recall. Microparticle separation demonstrated an accuracy of 98.1 ± 1% at a TFR of 2 mL/h in both simulations and experimental conditions. The Lagrangian model effectively captured the dynamics of magnetite microparticle separation from polystyrene microparticles, with close agreement between simulated and experimental results. Our findings underscore the device's robust capability in distinguishing between magnetic and non-magnetic particles at both micro- and nanoscales. This study highlights the potential of low-cost, non-cleanroom manufacturing techniques to produce high-performance microfluidic devices, thereby expanding their accessibility and applicability in various industrial and research settings. The integration of a continuous magnet, as opposed to segmented magnets in previous designs, was identified as a key factor in enhancing magnetic separation efficiency.

Regional mangrove vegetation carbon stocks predicted integrating UAV-LiDAR and satellite data

Using satellite RS data predicting mangrove vegetation carbon stock (MVC) is the popular and efficient approach at a large scale to protect mangroves and promote carbon trading. Satellite data have performed poorly in predicting MVC due to saturation issues. UAV-LiDAR data overcomes these limitations by providing detailed structural vegetation information. However, how to cross-scale integration of UAV-LiDAR and satellite RS data and the selection of features and machine learning methods hampered the practitioner in making a lightweight but efficient model to predict the MVC. Our study integrated UAV-LiDAR, Sentinel-1, and Sentinel-2 to extract spectral, structural, and textural features at the regional scale. We estimated the influences of different combinations between three vegetation features and machine learning methods (Support Vector Machine (SVM), Random Forest (RF), Gradient Boosting Regression Tree (GBDT), and Extreme Gradient Regression Tree (XGBOOST)) on the results of MVC prediction, and constructed a framework for estimating mangrove vegetation aboveground (ACG) and belowground (BCG) carbon storage in Zhanjiang, the largest mangrove area of China. Our research shows: 1) Compared to using satellite remote sensing (RS), integrating UAV and satellite RS data and fusing multiple vegetation features significantly improved the accuracy of mangrove vegetation carbon stock (MVC) predictions. 2) Structural features, particularly canopy height retrieved from UAV and satellite RS, are essential indicators for predicting MVC. Combined with spectral and structural features, regional MVC was precisely predicted. 3)Although the influence of different machine learning methods on MVC prediction was not significant, XGBOOST demonstrated relatively high precision. We recommend that mangrove practitioners integrate UAV and satellite RS data to predict MVC at a regional scale. Importantly, governments should prioritize the application of UAV-LiDAR in forestry monitoring and establish a long-term mangrove monitoring database to aid in estimating blue carbon resources and promoting blue carbon trading.

Widespread crab burrows enhance greenhouse gas emissions from coastal blue carbon ecosystems

Fiddler crabs, as coastal ecosystem engineers, play a crucial role in enhancing biodiversity and accelerating the flow of material and energy. Here we show how widespread crab burrows modify the carbon sequestration capacity of different habitats across a large climatic gradient. The process of crab burrowing results in the reallocation of sediment organic carbon and humus. Crab burrows can increase more greenhouse gases emissions compared to the sediment matrix (CO2: by 17–30%; CH4: by 49–141%). Straightforward calculations indicate that these increased emissions could offset 35–134% of sediment carbon burial in these two ecosystems. This research highlights the complex interactions between crab burrows, habitat type, and climate which reveal a potential lower carbon sink function of blue carbon ecosystems than previously expected without considering crab burrows.

Can coastal and marine carbon dioxide removal help to close the emissions gap? Scientific, legal, economic, and governance considerations

In this Policy Bridge, we present the key issues regarding the safety, efficacy, funding, and governance of coastal and marine systems in support of climate change mitigation. Novel insights into the likely potential of these systems for use in mitigating excess carbon dioxide emissions are presented. There may be potential for coastal blue carbon and marine carbon dioxide removal (mCDR) actions to impact climate change mitigation significantly over the rest of the 21st century, particularly post 2050. However, governance frameworks are needed urgently to ensure that the potential contribution from coastal and ocean systems to climate change mitigation can be evaluated properly and implemented safely. Ongoing research and monitoring efforts are essential to ensure that unforeseen side effects are identified and corrective action is taken. The co-creation of governance frameworks between academia, the private sector, and policymakers will be fundamental to the safe implementation of mCDR in the future. Furthermore, a radical acceleration in the pace of development of mCDR governance is needed immediately if it is to contribute significantly to the removal of excess carbon dioxide emissions by the latter half of this century. To what extent large-scale climate interventions should be pursued is a decision for policymakers and wider society, but adaptive legal, economic, policy, research, and monitoring frameworks are needed urgently to facilitate informed decision-making around any implementation of mCDR in the coming decades. Coastal and ocean systems cannot be relied upon to deliver significant carbon dioxide removal until further knowledge of specific management options is acquired and evaluated.

Interconnectivity can be as important as habitat type in explaining carbon stocks in the coastal lagoons of arid regions

Coastal blue carbon ecosystems, typically comprising interconnected habitat mosaics, are globally important pathways of carbon sequestration and play a significant role in climate change regulation and mitigation. Current coastal management strategies often rely on simplified regional carbon stock estimates, that overlook the geographical variability and intricate ecological dynamics within these ecosystems. This study adopts a seascape ecology approach to evaluate the role of multiple seascape characteristics on carbon storage in two arid region coastal lagoons. We show that seascape location is the most influential driver of carbon stocks. Additionally, carbon isotopic variability, a proxy for connectivity, can be as influential as habitat type, particularly in the UAQ lagoon. This challenges the conventional reliance on data from individual habitat types (e.g., seagrass, mangrove, or tidal marsh) and highlights the context-dependency of carbon stocks. Moreover, the specific characteristics driving carbon stocks vary between seascapes: in Khor Faridah, connectivity to seagrass and mangrove habitats is crucial, while in the UAQ lagoon, sheltered and elevated areas are more influential. Our findings suggest that the interconnectivity between different habitat types, such as mangroves and saltmarshes, significantly enhances carbon storage. This is especially pronounced in large, sheltered mangrove habitat types within upper intertidal zones. Notably, small patches of mangroves, up to 10 ha, are associated with an approximate 10 % increase in carbon stocks. These results underscore the need for a more holistic, context-specific approach to designing nature-based solutions for coastal management and ecosystem restoration. By considering the specific characteristics and connectivity of seascape mosaics, we can more effectively enhance carbon stock potential in coastal ecosystems. This study contributes to a deeper spatially explicit understanding of the complex factors influencing carbon stocks in blue carbon ecosystems, highlighting the importance of tailored management strategies that reflect the unique ecological patterns of each seascape.

Multi-deformable interpenetrating network thermosensitive hydrogel fluorescent device for real-time and visual detection of nitrite

Functionalized thermosensitive hydrogel materials exhibit excellent properties for the fabrication of sensing devices that enable real-time visual detection of food safety duo to their good plasticity and powerful loading capacity. Here, a ratiometric fluorescent device based on an interpenetrating network (IPN) thermosensitive hydrogel was designed to embed functionalized Au nanoclusters (Au NCs) and Blue Carbon dots (BCDs) composites in a multi-network structure to build a sensitive hazardous material nitrite (NO2-) chemsensor. The hydrogel was utilized poloxamer 407 (P407), lignin and cellulose to form stable IPN structure, which resulted in complementation and synergy, thereby strengthening its porous network structure. The combination of fluorescent nanoprobes with the porous network structure has the potential to enhance stable fluorescence signals and improve sensing sensitivity. Moreover, the thermosensitive liquid-solid transition characteristics of the hydrogel facilitate its preparation into diverse sensing devices following curing at room temperature. The hydrogel device, when combined with a smartphone system, converted image information into data information, thereby enabling the accurate quantification of NO2- with a detection limit of 9.38 nM in 2 s. The designed multi-functional hydrogel device is capable of real-time differentiation of NO2- dosage with the naked eye, offering a high-contrast, rapid-response sensing methodology for visual assessment of food freshness. This research contributes to the expansion of hydrogel materials applications and the detection of hazardous materials in food safety.

Net evaporation-induced mangrove area loss across low-lying Caribbean islands

Abstract Although mangroves provide many beneficial ecosystem services, such as blue carbon storage and coastal protection, they are currently under threat due to changes in climate conditions, such as prolonged drought exposure. Under drought conditions, evaporation exceeds precipitation and high soil salinities can lead to stunted growth and die-back. To quantify this interplay, we developed a database for low-lying and uninhabited mangrove islands in the Caribbean under various evaporation and precipitation regimes. We extracted physical and biological information from each island using remote sensing techniques and coupled it with a process-based model. We used this database to develop a model that explains both the spatial variability in vegetated area across the Caribbean—as a function of rates of evaporation and precipitation—and porewater salinity concentration and dispersion from island edge towards the interior of mangrove islands. We then used this validated model to predict mangrove area loss associated with increases in evaporation to precipitation rates by 2100 for different Shared Socioeconomic Pathways (SSP). Less wealthy Caribbean regions such as Belize, Puerto Rico, and Venezuela are disproportionally affected, with mangrove area losses ranging from 3%–7% for SSP 2.6 and 13%–21% for SSP 7.0. Furthermore, foregone carbon sequestration in lost biomass under SSP 4.5 and 7.0 scenarios could compromise the ability of low-lying Caribbean mangrove islands to vertically adjust to sea level rise.

Harnessing the potential: exploring development opportunities and charting strategic pathways for China’s enhanced engagement in international blue carbon cooperation

Abstract In light of the urgent need to combat climate change and attain carbon neutrality, the development of blue carbon has emerged as a pivotal strategy for the global community. This approach offers significant potential for both mitigating and adapting to the impacts of climate change. As a result, international collaboration on blue carbon initiatives has become a focal point in the worldwide response to the climate crisis. China, blessed with extensive blue carbon resources, recognizes the development of these ecosystems as a critical component in its efforts to make a substantial contribution to the global endeavor to curb climate change and achieve sustainable environmental goals. This article offers a comprehensive analysis of China’s opportunities and challenges in international blue carbon collaboration. Despite its vast potential, China faces significant hurdles, including the degradation of blue carbon ecosystems, a delayed start in implementing blue carbon practices, and inconsistencies in the blue carbon standard system. To enhance its participation in global blue carbon initiatives, China should pursue several key strategies, including preserving and restoring its blue carbon ecosystems, strengthening domestic protection and application mechanisms, promoting the construction of an international blue carbon system, establishing a scientific cooperation platform to facilitate capacity building and technology transfer and advocating for an international blue carbon market trading mechanism. By prioritizing these key areas, China can simultaneously foster domestic blue carbon conservation and development while solidifying its role as a pivotal contributor to global climate change mitigation efforts.

Climate change mitigation strategy through blue carbon in seagrasses ecosystem, Red Sea Coast, Egypt

Climate change mitigation strategy through blue carbon in seagrasses ecosystem, Red Sea Coast, Egypt

Construction of carbon quantum dots/riboflavin fluorescent probe and its application in the detection of ciprofloxacin.

The research outlined a novel approach for creating a sensitive and efficient ratio fluorescent probe for ciprofloxacin (CIP) detection. The method used the biomass materials passionfruit shell and diethylenetriamine as carbon and nitrogen sources, respectively, to prepare blue fluorescent carbon quantum dots (b-CQDs) with an average size of 3.29 nm and a quantum yield of 19.6% by a hydrothermal method. The newly designed b-CQDs/riboflavin ratio fluorescent probe demonstrates a distinct advantage for CIP monitoring, exhibiting a marked increase in fluorescence intensity at 445 nm upon interaction with CIP, while maintaining a stable intensity at 510 nm. In the water system, the I445 nm/I510 nm ratio of the fluorescent probe showed a significant linear relationship with CIP at the concentrations of 0-250 μmol·L-1, and the probe boasts a low detection limit of 0.86 μmol·L-1. The outstanding selectivity, broad detection range, low detection limits, and high quantum yield of the b-CQDs highlight their significant potential in the development of advanced sensing probes for efficient detection of ciprofloxacin, offering promising insights for future sensor technology advancements.

Luminous blue carbon quantum dots employing Anisomeles indica (catmint) induce apoptotic signaling pathway in triple negative breast cancer (TNBC) cells.

Herein, luminous blue carbon quantum dots (CDs) employing Anisomeles indica (Catmint) were reported with imaging, self-targeting, and therapeutic effects on triple-negative breast cancer (TNBC, MDA-MB-231) cells. The salient features of CDs generated from catmint are as follows: i) optical studies confirm CDs with excitation-dependent emission; ii) high-throughput characterization authenticates the formation of CDs with near-spherical shape with diameter ranging between 5 and 15 nm; iii) CDs induce cytotoxicity (3.22 ± 0.64 μg/ml) in triple-negative breast cancer (TNBC, MDA-MB-231) cells; iv) fluorescence microscopy demonstrates that CDs promote apoptosis by increasing reactive oxygen species (ROS) and decreasing mitochondrial membrane potential; v) CDs significantly up-regulate pro-apoptotic gene expression levels such as caspases-8/9/3. Finally, our work demonstrates that catmint-derived CDs are prospective nanotheranostics that augment cancer targeting and imaging.

Modelling the spatiotemporal dynamics of blue carbon stocks in tidal marsh under Spartina alterniflora invasion

Spatial quantification of blue carbon ecosystem stocks is crucial for developing policies to mitigate climate change, especially in regions experiencing ongoing wetland disturbance from biological invasions. We integrated multiple machine learning models with the space-for-time substitution method to quantify the spatiotemporal impact of Spartina alterniflora invasion on tidal marsh sediment blue carbon (soil organic carbon – 'SOC') stocks at 100 cm depth in the Yangtze Estuary. Our results show that the invasive S. alterniflora contributed more than half of the total SOC stocks (2,056 ± 379 Gg C, 1 Gg = 106 kg) in the 27,600 ha tidal marshes of the Yangtze Estuary, which were estimated to be 1,107 ± 176 Gg C. S. alterniflora increased the SOC stocks in the Yangtze Estuary within the first 15 years, but this gain was not sustained in the long term, with a gradual decline (by 13.14 Mg C/ha) observed after 15 years of S. alterniflora growth. We found that sediment salinity, tidal range, and human accessibility were strong indicators for modeling and predicting SOC stocks, with Random Forest providing the best simulation of tidal marsh SOC stocks (R2 = 0.894, RMSE=7.646 Mg C/ha, and MAPE=9.469 %). Our study provides much needed information on blue carbon stocks in the Yangtze Estuary under biological invasion stress, and offers guidance for targeted S. alterniflora management actions in the future.