Mangroves have among the highest carbon densities of any tropical forest. These ‘blue carbon’ ecosystems can store large amounts of carbon for long periods, and their protection reduces greenhouse gas emissions and supports climate change mitigation. Incorporating mangroves into Nationally Determined Contributions to the Paris Agreement and their valuation on carbon markets requires predicting how the management of different land‐uses can prevent future greenhouse gas emissions and increase CO2 sequestration. We integrated comprehensive global datasets for carbon stocks, mangrove distribution, deforestation rates, and land‐use change drivers into a predictive model of mangrove carbon emissions. We project emissions and foregone soil carbon sequestration potential under ‘business as usual’ rates of mangrove loss. Emissions from mangrove loss could reach 2391 Tg CO2 eq by the end of the century, or 3392 Tg CO2 eq when considering foregone soil carbon sequestration. The highest emissions were predicted in southeast and south Asia (West Coral Triangle, Sunda Shelf, and the Bay of Bengal) due to conversion to aquaculture or agriculture, followed by the Caribbean (Tropical Northwest Atlantic) due to clearing and erosion, and the Andaman coast (West Myanmar) and north Brazil due to erosion. Together, these six regions accounted for 90% of the total potential CO2 eq future emissions. Mangrove loss has been slowing, and global emissions could be more than halved if reduced loss rates remain in the future. Notably, the location of global emission hotspots was consistent with every dataset used to calculate deforestation rates or with alternative assumptions about carbon storage and emissions. Our results indicate the regions in need of policy actions to address emissions arising from mangrove loss and the drivers that could be managed to prevent them.
Tag: coastal areas
Assessment of coastal vulnerability to support mangrove restoration in the northern coast of Java, Indonesia
The northern coast of Java has been more severely affected by sea level rise (SLR) than other islands in the Indonesian archipelago. This warrants a coastal area risk assessment to ascertain the multiple hazards that could impact on this densely populated island. Using environmental and physical variables – including geomorphology, rate of shoreline change, sea level rise, wave height, coastal slope, bathymetry, tidal range, and mangrove density – the main objective of this study is to determine a coastal vulnerability index (CVI) and mangrove vulnerability index (MVI) in the northern Javanese coastline. Assessment was carried out for three regencies – Banten, Demak, and Banyuwangi regency – with the goal of helping to identify areas where mangrove restoration efforts can be prioritized. Using line and 1 × 1 km2 grid representation of the entire coastline, the research found that in terms of CVI, Demak coast is most vulnerable (with 82% of grids and 89% of coastline falling into the highly vulnerable categories), Banten coast ranked as moderately vulnerable (43% of grids and 35% of coastline fall into the moderately vulnerable categories), while 91% of grids and 93% of coastline in Banyuwangi fall into the least vulnerable category. Assessment of mangrove vulnerability revealed that Banten and Banyuwangi regency were low vulnerability as respectively, 100% and 94% of grids fell into this category, while Demak coast was highly vulnerable (with 46% of grids falling into highly vulnerable categories). This vulnerability mapping provides useful information to assist planners and managers to deploy resources for mangrove restoration and the long-term sustainable management of these coastal ecosystems.
Dietary diversity and fish consumption of mothers and their children in fisher households in Komodo District, eastern Indonesia
Small-scale coastal fisheries contribute directly and indirectly to the food and nutrition security of marine-dependent households. Fishers can apportion part of their catch for household consumption or use the income earned to purchase staples and other desired foods. Fish are an important animal-source food rich in micronutrients essential for cognitive development of children and for adult health, and a valuable addition to rice-based diets. Furthermore, the engagement of women in fisheries value chains and increased control over income may facilitate decision-making which improves nutrition outcomes for women and their children. Despite these contributions, food insecurity remains prevalent in many low and middle income fish-producing countries. This paper reports findings from an exploration of the interplaying factors leading to food and nutrition insecurity in three marine-dependent coastal communities in eastern Indonesia, focusing on the consumption pathway, that is, the contribution of fish to the diets and nutrition of women and children. The research was undertaken as a mixed-methods case study. The study found that over 50% of mother-child pairs failed to meet the minimum recommended dietary diversity, and, while fish was the main animal-source food in diets, the introduction of fish to infant and young child diets was delayed due to fears of allergies and illnesses. Moreover, access to nutrient-dense foods was affected by variable and insufficient income from fisheries-based livelihoods, isolation from markets, and the broader food environment. Given the shift towards ‘nutrition-sensitive interventions’ to improve the livelihoods and well-being of fisher households, these results highlight the need for analysis of the intra-household sharing of fish within fisher households, culturally-appropriate strategies to improve the quality of family and especially complementary foods, and efforts to increase physical access to nutrient-dense foods.
Assessment of coastal and mangrove vulnerability in the Andaman Island, Indian Ocean
Coastal regions are highly susceptible to the effects of global warming, including rising atmospheric and sea surface temperatures, increased cyclone frequency, and sea level rise. Thus, it is imperative to examine coastal vulnerability to minimize the impact of multiple hazards and protect coastal resources, such as mangroves. Particularly in India studying the vulnerability of coastal zones of Andaman and Nicobar Islands which fall in seismic zone V is critical for conservation efforts. We conducted vulnerability analysis of coastal zones impacted by the 2004 earthquake, causing varying degrees of ground upliftment and subsidence. We compared coastal vulnerability among sites that experienced uplift, no change, and subsidence (the southern portion). Our analysis utilized the Coastal and Mangrove Vulnerability Index (CVI and MVI) to measure and compare vulnerability in six zones distributed along uplift and subsidence gradient. High-resolution satellite imagery including WorldView-2, 3, and GeoEye-1 from year 2022 are utilized on this study. The CVI and MVI offers a good way to measure and compare vulnerabilities across sites and offer insights for better management. The CVI and MVI results indicate that approximately 34% of coastal grids and over 23% of mangrove grids across all zones are highly to extremely highly vulnerable. Subsided zones were found to be more vulnerable than uplifted zones. These findings suggest that large-scale natural disturbances such as tectonic displacement have the potential to impact coastal vegetation and mangrove cover can become even more vulnerable. In conclusion, our study emphasizes the importance of vulnerability analyses in coastal regions, especially in areas prone to seismic activity. Our findings have direct implications for conservation and restoration efforts and underscore the need for continued monitoring and mitigation efforts to safeguard coastal resources for long-term sustainability.
All tidal wetlands are blue carbon ecosystems
Managing coastal wetlands is one of the most promising activities to reduce atmospheric greenhouse gases, and it also contributes to meeting the United Nations Sustainable Development Goals. One of the options is through blue carbon projects, in which mangroves, saltmarshes, and seagrass are managed to increase carbon sequestration and reduce greenhouse gas emissions. However, other tidal wetlands align with the characteristics of blue carbon. These wetlands are called tidal freshwater wetlands in the United States, supratidal wetlands in Australia, transitional forests in Southeast Asia, and estuarine forests in South Africa. They have similar or larger potential for atmospheric carbon sequestration and emission reductions than the currently considered blue carbon ecosystems and have been highly exploited. In the present article, we suggest that all wetlands directly or indirectly influenced by tides should be considered blue carbon. Their protection and restoration through carbon offsets could reduce emissions while providing multiple cobenefits, including biodiversity.
Mangrove vegetation response to alteration in coastal geomorphology after an earthquake in Andaman Islands, India
The 2004 Sumatra-Andaman earthquake caused a devastating tsunami and shifts in land elevations, which had an instantaneous as well as the long-term impact on the ecology of Andaman Islands. Especially, the coastal uplift and subsidence has altered the tidal regime, leading to mass mortality and degradation of mangroves (~150 sq. km). The tectonic shift in the Andaman archipelago has created three broader geographical units: North Andaman with coastal uplift (~1.3 m)– sea level drop (SLD) scenario; Middle Andaman with minor to no change in coastal geomorphology – no change scenario; and South Andaman with coastal subsidence (~1.1 m)– sea level rise (SLR) scenario. How these changes in tidal regime has influenced mangrove vegetation remain less understood. Therefore, we assessed mangrove vegetation characteristics across the Andaman Islands to examine mangrove response to coastal uplift and subsidence after 16 years since the disturbance. The uplifted sites mimicking SLD scenario appeared more destructive to vegetation (tree density – 771/ha) in comparison to subsided sites mimicking SLR scenario (tree density – 937/ha), while no change sites with highest tree density (1288/ha) showed lowest impacts to vegetation. The species diversity (H’=Shannon-Wiener index) within recruitment cohorts (seedlings: <1 cm DBH and saplings: ≥1 cm and <5 cm DBH) sapling (H’=1.57), and seedling (H’=1.48) was significantly higher than the trees (H’=1.2). Rhizophora apiculata and Ceriops tagal were the dominant species (cumulative IVI 60%) found in survived mangrove forests demonstrating their high resilience for sudden changes in tidal regime. Our study provided a comprehensive account of mangrove vegetation response after a major disruptive event in 2004. Long-term monitoring of these novel sites would enhance our understanding of mangrove response to sea level change, which can also provide significant insights for restoration and management of mangroves.
Mangrove Monitoring for Climate Change Mitigation in India
Mangroves are recognized as one of the prominent naturebased solutions to climate change due to their capacity to store high levels of carbon and for enhancing resilience of ecosystems and living organisms to increased vulnerability. Global extent of mangroves is estimated to be ~ 150,000 square kilometers, distributed across more than 100 tropical countries. The mangroves have reduced by ~40% from their historical extent due to direct pressures caused by anthropogenic demands on mangrove resources and indirectly by the destruction of conditions suitable for mangrove survival.
Strengthening Ecological Monitoring for Mangrove Management in West Bengal: Sundarbans
Coastal ecosystems and their diverse biodiversity are under threat due to the impacts of global climate change, specifically due to rising sea levels. Mangroves, crucial as socio-ecological systems, play a vital role in combating climate change, safeguarding coastlines, and sustaining the livelihoods of coastal communities.
Strengthening Ecological Monitoring for Mangrove Management in Andhra Pradesh: Coringa Wildlife Sanctuary
Coastal ecosystems and associated biodiversity are under severe threat due to global climate change and subsequent sea level rise (SLR). Mangroves, as a socio-ecological system, are of paramount importance for combating climate change, ensuring the sustainability of coastlines, and supporting coastal communities. Despite providing numerous ecosystem services and tangible benefits to society, these ecosystems are facing immense pressure from both anthropogenic and natural causes.
Influence of Earthquake Induced Geo-tectonic Shift on Coastal Mangrove Forests of Andaman Islands, India
Conservation and sustainable management of the blue carbon ecosystems form a significant part of our strategies for mitigating the impacts of climate change. Mangroves are one such socio-ecological system that ensures the sustainability of coastlines and the sustenance of coastal communities in response to changing climate. However, accelerated climate change events (e.g., Sea level rise) present a challenge for natural adaptation processes. A lack of site-specific information and scientific data on these vulnerable zones limits our ability to respond to such challenges and apply appropriate nature-based solutions.