International Conference on Mangroves for Sustainability - 2026

Blue Carbon Stock Mapping of the Sundarbans Mangrove Ecosystem, Bangladesh (2000–2025): A Hybrid GeoAI Ensemble Framework

2026-09-09T10:00:50Z

Blue Carbon Stock Mapping of the Sundarbans Mangrove Ecosystem, Bangladesh (2000–2025): A Hybrid GeoAI Ensemble Framework Zubyer, S.; Hasan, M.R; Arabi, F.Z. The Sundarbans mangrove system constitutes a globally consequential blue carbon sink, yet vertically resolved soil organic carbon (SOC) inventories, particularly at depth, remain under- constrained. This study deployed a geospatial deep-learning pipeline integrating multi-source Earth observation data (optical, SAR, and DEM-derived covariates) to spatially upscale SOC stocks to 1m depth across the Bangladesh Sundarbans. Stratified coring across five sites positioned along the salinity-tidal inundation gradient to represent four major vegetation zones (n=25; one pit per site × five depth intervals: 0-20, 20-40, 40-60, 60-80, 80-100cm) captured physicochemical and SOC attributions. A Kruskal–Wallis test confirmed a positive SOC gradient with depth (H=21.7, df = 4, p<0.001); post-hoc Dunn's pairwise comparisons showed 60–100cm layers differed significantly from all shallower layers (p<0.01, Bonferroni-adjusted), with the dominant pool residing below 40cm, implying systematic underestimation by conventional shallow-core (≤30–40 cm) assessments. To partition total ecosystem carbon and establish soil-pool dominance, above and belowground biomass were parameterized using species-specific allometric equations, revealing high stem density but comparatively low basal area consistent with a regenerating stand structure dominated by Heritiera fomes and Sonneratia apetala. Analysis of a previously published Landsat-derived mangrove record (1988–2022) revealed net contraction in mangrove extent; loss-agent raster attribution, based on shoreline-proximity buffers, land-cover transition sequences and cyclone-track coincidence, identified chronic tidal abrasion and erosion as the primary driver rather than anthropogenic conversion or cyclonic disturbance. Benchmarking against a previously published global30m machine-learning SOC product revealed a 4.2 fold underestimation of SOC stocks in the Bangladesh Sundarbans, particularly in peat-enriched, anoxic substrata. Assimilation of deep-profile in situ observations with the pipeline significantly improves spatial prediction fidelity and establishes a robust baseline for Measurement, Reporting, and Verification for greenhouse gas inventories, highlighting the necessity of incorporating deep-soil carbon pools for inventorizing erosion-vulnerable seaward margins.

Microplastic Contamination in Mangrove Ecosystems in Sri Lanka: Policy Implications and Integration of Global Regulatory Frameworks

2026-09-09T09:58:55Z

Microplastic Contamination in Mangrove Ecosystems in Sri Lanka: Policy Implications and Integration of Global Regulatory Frameworks Wimalasekara, R.H.K. Mangrove ecosystems are vital coastal habitats that deliver critical ecosystem services. However, dense mangrove root systems efficiently entrap and accumulate microplastics (MPs), converting these ecosystems into long-standing sinks for MPs pollution. In Sri Lanka, growing microplastic pollution, linked with the lack of microplastic-specific policy and regulatory framework, inadequate environmental examining, insufficient scientific evidence, institutional fragmentation and poor coordination. These deficiencies have generated major policy and governance gaps, resulting in disintegrated management of MPs contamination across interconnected riverine, estuarine, and coastal ecosystems. This review synthesizes existing knowledge on mangrove microplastic pollution, critically evaluates Sri Lanka's National Environmental Policy and regulatory framework, and reviews the global policy framework on MP pollution control through a comprehensive literature review. The methodology is structured into three sections: (a) study of the plastic lifecycle and microplastic toxic contaminants affecting mangrove ecosystems; (b) an extensive review of microplastic contamination research trends in Sri Lanka, with specific attention on riverine, coastal and estuarine mangrove ecosystems; and (c) an evaluation of global microplastic policy and regulatory frameworks and adaptable policy responses for nationwide mangrove conservation. The review further examines the appropriateness of existing global regulatory mechanisms, including the European Union REACH Synthetic Polymer Microparticles (SPM) Restriction, the EU plastic pellet regulation-2025 on strict rules to prevent pellet losses, and the United Nations Global Plastics Treaty, to create a cohesive policy pathway for Sri Lanka’s MP pollution control. By examining these internationally recognized frameworks and mechanisms, this study identifies key policy implications, including the need to regulate globally generated microplastics, prevent industrial pellet loss into the environment, and develop standardized protocols for routine monitoring and assessments. Furthermore, the paper outlines future research and policy directions, emphasizing the importance of scientific monitoring, interdisciplinary research, and integrated river- to -mangrove management approaches. These measures are essential for fostering evidence-based policymaking and achieving effective control of microplastic contamination across interlinked freshwater, estuarine and mangrove ecosystems.

Assessment of Macro Debris in Selected Mangrove Ecosystems in Batticaloa Lagoon, Sri Lanka

2026-09-09T09:57:55Z

Assessment of Macro Debris in Selected Mangrove Ecosystems in Batticaloa Lagoon, Sri Lanka Wijethunga, W.M.K.D.R.; Analuxshana, N.; Dilthara, R.M.O.; Ranathunge, S.N.; Mathushan, R.; Mahagamage, M.G.Y.L. Mangrove ecosystems serve as a vital coastal buffer and biodiversity conservation, yet they are vulnerable to anthropogenic debris accumulation. The present study identified the composition, abundance and spatial distribution of macro debris within the mangrove ecosystem of Batticaloa Lagoon. The belt transect method (25m × 2m) was used perpendicular to the shoreline to collect macroplastics in five selected locations within the Batticaloa lagoon during June 2026, with each transect subdivided into 0-5m, 5-15m, and 15-25m segments from the shoreline to capture the crossshore distribution of debris. Macro debris was classified into Polyethylene Terephthalate (PET), Highdensity polyethylene (HDPE), Low-density polyethylene (LDPE), Polypropylene (PP), Polystyrene (PS), Other plastics, and Synthetic rubber. Debris count (items/m2) and Plastic Abundance Index (PAI) were calculated, while item color, original purpose, and manufacturing/expiration dates were recorded. A total of 582 debris items (20.09 kg) were recorded across all locations, with an overall average debris density of (0.78±0.21 items/m2). Debris density showed a marked decline with increasing distance from the shoreline; the 0-5 m zone recorded the highest average density (3.51±1.05 items/m2), followed by the 5-15m zone (0.10±0.04 items/m2), while the 15-25 m zone recorded the lowest density (0.01±0.02 items/m2). PET was the most dominant polymer by mass, accounting for 24.35 % of the total weight. Plastic abundance was highest at location 1 (PAI=0.12) and lowest at location 5 (PAI=0.10). PET bottles were the most common items; mainly transparent and green colors bottles were recorded compared to other colors. Study results revealed macro debris accumulation in mangrove ecosystems, and they emphasize the need of targeted waste management strategies to protect mangrove ecosystems in Batticaloa Lagoon.

Assessment of Total Ecosystem Carbon Stock Dynamics in Natural, Restored Mangrove and Abandoned Shrimp Pond Areas in the Pubudugama Accelerated Natural Regeneration of Mangroves Site, Sri Lanka

2026-09-09T09:55:59Z

Assessment of Total Ecosystem Carbon Stock Dynamics in Natural, Restored Mangrove and Abandoned Shrimp Pond Areas in the Pubudugama Accelerated Natural Regeneration of Mangroves Site, Sri Lanka Wijerathna, D.K.G.K.D.; Kekulandara, K.M.H.G.N.S.B.; Gajanayakage, H.G.W.; Tissera, P.M.W.S.R.; Kumarasiri, H.N.T.M.; Dilshara, K.K.; Jayakody, S. Mangroves act as critical blue carbon sinks and play a vital role in climate change mitigation. Mangroves in Pubudugama, Puttalam district, have been extensively destroyed for aquaculture. Currently, abandoned shrimp ponds in the area are being restored through the Accelerated Natural Regeneration of Mangroves (ANRM) project. This study aimed to determine the Total Ecosystem Carbon Stocks (TECS) in natural mangroves, degraded areas, and areas under restoration, commenced in 2019, 2020, 2020/2021, and 2024. TECS were quantified by measuring four primary pools: aboveground, below-ground, soil, and downed wood carbon. The stratum consists of three 50 m Ẋ 50 m main plots, each containing five 7m radius subplots (one central, four at corners). Soil samples were collected to a depth of 1 m across four intervals, yielding 5 samples per main plot for a total of 15 samples per strata. Other carbon pool data were collected from these same locations. Soil organic carbon was determined by loss on ignition (LOI), and vegetation biomass was estimated using allometric equations. Mean TECS values varied significantly across the six sites, according to the one-way ANOVA. Mean TECS was highest at the natural site (860±201 Mg ha-1), next at the 2019 restoration site 625±17.4 and the lowest at the 2020/2021 and 2020 sites (136±17.6 Mg ha-1, 131±67.2 Mg ha-1). The degraded area contained only soil organic carbon and exhibited no above and below-ground carbon pools. All forms of carbon were present only in the natural environment. The 2019 restoration site recorded the highest mean above-ground (123±68.2 Mg ha-1) and below-ground (92.3±52 Mg ha-1) carbon stocks. These findings show that natural mangroves in Pubudugama possess significantly higher carbon stocks than degraded or actively restored areas, with restoration efforts able to recover lost carbon reserves gradually. The results serve as a baseline for adaptive management of the ANRM project and inform blue carbon accounting in Sri Lanka.