Mangrove Ecosystem Management Research Articles

Dynamic Estimation of Mangrove Carbon Storage in Hainan Island Based on the InVEST-PLUS Model

Mangrove ecosystems are pivotal to the global carbon budget. However, there is still a dearth of research addressing the impact of regional mangrove land use and land cover change (LUCC) on carbon sequestration and its associated spatial distribution patterns. To investigate the impact of different development scenarios on the carbon storage capacity of mangrove ecosystems, we focused on Hainan Island. We used LUCC data from 2010 to 2020 from mangrove-inhabited regions. The Markov-PLUS model was applied to predict the spatiotemporal dynamics of mangrove coverage under the natural increase scenario (NIS) and the mangrove protection scenario (MPS) over the next 40 years. Carbon storage was estimated using the InVEST model based on field-measured carbon density data. The outcomes show the following: (1) The Markov-PLUS model, with an overall accuracy of 0.88 and a Kappa coefficient of 0.82, is suitable for predicting mangrove distribution patterns on Hainan Island. (2) Environmental factors were the main drivers of historical mangrove changes on Hainan Island, explaining 54% of the variance, with elevation, temperature, and precipitation each contributing over 13%. (3) From 2025 to 2065, the mangrove area on Hainan Island is projected to increase by approximately 12,505.68 ha, mainly through conversions from forest land (12.73% under NIS and 12.37% under MPS) and agricultural land (39.72% under NIS and 34.53% under MPS). (4) The carbon storage increment within Hainan Island’s mangroves is projected at 2.71 TgC over the whole island, with notable increases expected in the eastern, northern, and northwestern regions, and modest gains in other areas. In this study, we comprehensively investigated the spatiotemporal dynamics and future trends of carbon storage in the mangroves of Hainan Island, offering invaluable guidance for the long-term management of mangrove ecosystems and the realization of carbon neutrality goals by 2060.

Human activities altered the enrichment patterns of microplastics in mangrove blue carbon ecosystem in the semi-enclosed Zhanjiang Bay, China

Mangroves, as the key blue carbon ecosystem, are considered ‘potential sinks’ for microplastics (MPs) in the land-ocean interface zones. However, there is limited understanding of enrichment patterns of MPs in mangrove blue carbon ecosystem, particularly in relation to human activities. This study explored the abundance, composition, and diversity of MPs in mangrove and non-mangrove sediments in Zhanjiang Bay (ZJB) to investigate the effects of human activities on MPs enrichment patterns in the blue carbon system. The results showed that MPs were widely prevalent in all sediment samples, and the abundance of MPs was significantly higher in all mangrove sediments than in non-mangrove sediments (P < 0.05). Furthermore, the average abundance of MPs was found to be 263.67 ± 85.25 items/kg in non-mangrove sediment samples, whereas in mangrove sediment samples, it was 618.17 ± 71.75 items/kg. The average abundance of MPs in mangroves was about 1.6 times higher than that in non-mangroves, indicating that mangroves have an interception effect on MPs, and human activities are the key factor leading to the difference in MPs enrichment patterns between mangroves and non-mangroves. Furthermore, the predominant MPs shapes in both mangroves and non-mangroves are fragments, with multicolor and green being the most common colors and most MPs sizes ranging between 100 and 330 µm. Besides, there was no significant relationship found between MPs abundance and particulate organic carbon (P > 0.05), indicating that MPs pollution didn’t significantly alter the natural POC pool in ZJB. Overall, this study provided important baseline information on MPs pollution in the mangrove blue carbon ecosystems in ZJB, which was implications for future mitigation of MPs pollution and the management of mangrove ecosystem.

Mangrove Ecosystem Management Strategy to Support Sustainable Development Goal 14

Sustainable mangrove management plays a pivotal role in advancing various sustainable development goals (SDGs). These encompass poverty and hunger eradication, fostering livelihoods and economic growth, countering the impacts of climate change, and protecting biodiversity. To investigate this matter, our study employed participatory rural appraisal (PRA) and focus group discussion (FGD) techniques. The study engaged with local government officials, fishermen, farmers, non-governmental organizations, women leaders, community leaders, and the general public actively involved in mangrove forest regions. The purposive sampling method ensured a representative sample. A comprehensive analysis was conducted, integrating SWOT analysis and the analytical hierarchy process (AHP). The findings revealed several key strategies: promoting the development of the potential of economically and sustainably valuable mangrove ecosystems through environmentally friendly planting and harvesting; empowering communities through farmers, fishermen, and women’s groups to generate household-scale mangrove-based industries; providing all necessary facilities and infrastructure for mangrove ecotourism visitors; expanding the role of non-governmental organizations (NGOs) in improving community awareness and knowledge on the management of mangroves; and providing training to increase the diversification of mangrove economic products.

THE LEGAL CONSTRUCTION OF MANGROVE PROTECTION IN CLIMATE CHANGE MITIGATION: LEGAL STUDY ON THE SOUTH SULAWESI SCALE

Mangroves are coastal ecosystems that play a vital role in protecting the environment and the economy, as well as aiding climate change mitigation. The mangrove rehabilitation program in South Sulawesi is a strategic step by the government to ensure the sustainability of coastal environments. The success of these efforts depends on the participation of all stakeholders. The aim of this research is to identify the impacts and implications of constitutional legal protection on the conservation, restoration, and management of mangrove ecosystems as part of climate change mitigation strategies in South Sulawesi. This research utilizes normative legal research methods with a focus on the legal framework related to Mangroves and Climate Change in South Sulawesi, exploring legal sources such as laws, regulations, and relevant legal documents, and applying document content analysis techniques and constitutional legal approaches to identify potential legal improvements in protecting mangroves and addressing climate change in the region. The research findings indicate that legal protection in South Sulawesi plays a crucial role in preserving and restoring the mangrove ecosystem and mitigating climate change. The enforcement of Law No. 32 of 2009 and local regulations provides a strong legal foundation for safeguarding the mangrove ecosystem through land permit restrictions and the establishment of conservation areas. Mangrove preservation policies are also applied at the national level with the support of Indonesia's FOLU Net Sink 2030 Operational Plan. South Sulawesi, through its regional mangrove working group, plays a key role in coordinating mangrove preservation efforts at the regional level. Furthermore, the role of the Indonesian President in the G20 Presidency underscores Indonesia's commitment to climate change mitigation, highlighting the preservation of the mangrove ecosystem as an example for other countries. With collaboration and community awareness, South Sulawesi has the potential to become a successful model in mangrove preservation and climate change mitigation, despite challenges such as economic issues, public awareness, and climate change

Sustainable management model and ecosystem services of mangroves based on socio-ecological system on the coast of Batu Bara Regency, Indonesia

The coastal areas of Batu Bara Regency, Indonesia, face significant challenges due to the conversion of mangrove ecosystems into ponds and tourist destinations. This transformation not only results in the loss of natural coastal protection but also disrupts hydro-oceanography patterns, necessitating comprehensive management solutions that address ecological, economic, and social aspects. To this end, a research was carried out during June to August 2023 developing an integrated management model for sustainable preservation of mangrove ecosystems in Batu Bara Regency. The research aims to evaluate the economic benefits of mangrove ecosystems, particularly emphasizing on regulating, provisioning, and cultural services. The Analytic Network Process (ANP) method is employed to determine priority management strategies by considering the interrelationships between ecological, economic, social, and institutional factors. The model construction incorporates insights from literature reviews and expert interviews, facilitating the formulation of solutions for various aspects of mangrove ecosystem management. The economic value of mangrove ecosystems is estimated in three districts of Batu Bara Regency, with significant contributions to both provisioning and regulating services. In conclusion, the research underscores the importance of strategies such as mangrove area rehabilitation, ecotourism development, outreach and assistance, and community involvement in ensuring the sustainable management of mangrove ecosystems. These strategies hold the potential to preserve these valuable ecosystems, benefiting the environment and local communities alike.

Macro-epibiont assemblages of mangrove forests in the Persian Gulf and Gulf of Oman

In mangrove ecosystems, trees and aerial roots provide a hard substrate for the attachment of several groups of epibiont species. However, the diversity and abundance of epibionts varies in different geographic areas and has not been studied in many regions. Here, we studied the species composition, abundance, and biomass of macro-epibionts on Avicennia marina tree surfaces and pneumatophores along the northern coasts of the Persian Gulf and Gulf of Oman. A total of four species of epibionts were recorded, including an oyster Crassostrea sp., two barnacles Amphibalanus amphitrite and Microeuraphia permitini, and a snail Littoraria intermedia. Species composition did not show significant differences among sites, while abundance and biomass differed significantly. Oysters accounted for the largest proportion of biomass in the epibiont assemblages. In contrast to the distinct vertical distribution of epibionts on tree surfaces, there was no clear geographic distribution pattern of species from the Persian Gulf to the Gulf of Oman. We suggest that the differences in mangrove epibiont assemblages are largely determined by local hydrographic conditions. These baseline data will contribute to the management and conservation of valuable mangrove ecosystems.

Pelatihan Metode Dan Analisis Studi Ekosistem Mangrove Pada Mahasiswa Ilmu Kelautan Universitas Pattimura

Mangroves provide various ecosystem services such as ecological, economic and social benefits for humans and the surrounding environment. As agents of future change, students have an important role in contributing new knowledge and innovative solutions for the preservation and management of mangrove ecosystems. Training activities are carried out to increase student perceptions of mangrove ecosystems and participation in research activities on current mangrove topics, namely blue carbon dynamics. Activities are evaluated through an open questionnaire with a Likert scale and analysis of the perception index. The results of the activity showed that the training activities on methods and analysis of mangrove ecosystem studies were very effective in increasing students' perceptions and understanding of mangrove ecosystems (IP = 0.71). In particular, training on the dynamics of blue carbon in mangroves can spark student interest, thereby increasing participation in research in this field. It can be seen from the seriousness of the students to determine the title that will be carried out as the final assignment in completing the study.

Understanding carbon storage dynamics in Ayeyarwady delta's mangrove ecosystem in Myanmar: insights for restoration efforts

Mangroves are highly valued for their ecosystem services, providing a wide range of ecological, social, and economic benefits, including their role as carbon-rich ecosystems. Recent research suggests that preserving mangrove forests can offer a cost-effective strategy for mitigating CO2 emissions. However, extensive deforestation has placed mangrove ecosystems under severe global threats. Currently, the assessment of mangrove restoration outcomes, particularly regarding soil carbon stocks, is inadequate. Therefore, this study aims to investigate the impact of restoration on soil organic carbon (SOC) in Shwe Thaung Yan, Ayeyarwady coastal region of Myanmar. The study aimed to quantify and compare carbon stocks in different soil layers, examine the carbon sequestration potential of various mangrove species, and evaluate the effectiveness of mangrove restoration efforts. Soil samples were collected in 2015 (pre-restoration) and 2021 (post-restoration) at various soil depths and analyzed for SOC concentration, organic matter content, and bulk density using the Loss on Ignition (LOI) procedure. Significant changes in soil properties were observed between 2015 and 2021, with higher SOC and carbon concentrations observed in 2021. The average soil carbon stocks in 2021 (1954.43 ± 33.24 Mg C ha−1) were approximately 2.7 times higher than the estimated carbon stocks in 2015 (732.26 ± 6.99 Mg C ha−1). Furthermore, the study revealed variations in SOC accumulation among different soil depths, with higher carbon stocks found in the upper soil layers. This study highlights the positive impact of mangrove restoration on SOC accumulation and emphasizes the significance of considering soil carbon dynamics in restoration initiatives. The findings offer valuable insights for the conservation and management of mangrove ecosystems, especially concerning their potential for carbon sequestration and their contribution to mitigating climate change.

Implementation of Mangrove Forest Rehabilitation in Urumb Village, Semangga District, Merauke Regency

In the Presidential Regulation of the Republic of Indonesia Number 73 of 2012 concerning the National Strategy for Mangrove Ecosystem Management, it is explained that the life support system and natural resources are of very high value, therefore efforts are needed to protect, preserve and use sustainably for the welfare of the community. The purpose of this study is to determine the implementation of the community in mangrove forest rehabilitation in Urumb village, Semangga District, Merauke Regency. The research was conducted from September to November 2022, in Urumb Village. The research method used was qualitative descriptive with Purpusive sampling technique by determining the number of samples using the Slovin formula with a tolerance degree of 10%, so that a sample of 92 respondents from 1020 populations was obtained. The data collected in this study are primary and secondary data. The data analysis used in the study used qualitative data analysis of the Miles and Huberman model. The implementation of mangrove rehabilitation in Urumb Village consists of four activities, namely; Enrichment of biological resources consisting of mangrove planting activities and mangrove habitat improvement. Habitat improvement carried out in Urumb village in habitat improvement activities is a ban on sand excavation. Protection of mangroves so that they grow and develop naturally and are environmentally friendly.
 Keywords: Implementation of Mangrove Rehabilitation; Urumb Village; Merauke

Analisis Persepsi Masyarakat Terhadap Pengelolaan Ekosistem Mangrov di Kawasan Mangrov Biringkassi Kabupaten Pangkep

This study aims to analyze public perception of mangrove management in the Biringkassi mangrove area of Pangkep regency. This research is important because the surrounding community does not get more education and attention from the government. This research is a descriptive research with a qualitative approach. Researchers conducted in-depth interviews with 45 purposively selected respondents using thematic category content analysis techniques to identify themes or patterns in the interview. The result: The level of understanding and knowledge of the community is low. Community participation is in the moderate category even though it is known that public perception of the benefits of mangrove ecosystems for them is quite good. Therefore, citizen involvement in maintaining mangrove ecosystems that are still at the middle level needs to be increased, and implementing programs such as: (1) increasing public awareness of the importance of mangrove ecosystems, (2) educating the public about mangrove ecosystem management, (3) intensifying government policies on planting and conservation, and (4) establishing effective communication between the government and the community

Evaluating Feature Selection Methods and Machine Learning Algorithms for Mapping Mangrove Forests Using Optical and Synthetic Aperture Radar Data

Mangrove forests, mostly found in the intertidal zone, are among the highest-productivity ecosystems and have great ecological and economic value. The accurate mapping of mangrove forests is essential for the scientific management and restoration of mangrove ecosystems. However, it is still challenging to perform the rapid and accurate information mapping of mangrove forests due to the complexity of mangrove forests themselves and their environments. Utilizing multi-source remote sensing data is an effective approach to address this challenge. Feature extraction and selection, as well as the selection of classification models, are crucial for accurate mangrove mapping using multi-source remote sensing data. This study constructs multi-source feature sets based on optical (Sentinel-2) and SAR (synthetic aperture radar) (C-band: Sentinel-1; L-band: ALOS-2) remote sensing data, aiming to compare the impact of three feature selection methods (RFS, random forest; ERT, extremely randomized tree; MIC, maximal information coefficient) and four machine learning algorithms (DT, decision tree; RF, random forest; XGBoost, extreme gradient boosting; LightGBM, light gradient-boosting machine) on classification accuracy, identify sensitive feature variables that contribute to mangrove mapping, and formulate a classification framework for accurately recognizing mangrove forests. The experimental results demonstrated that using the feature combination selected via the ERT method could obtain higher accuracy with fewer features compared to other methods. Among the feature combinations, the visible bands, shortwave infrared bands, and the vegetation indices constructed from these bands contributed the greatest to the classification accuracy. The classification performance of optical data was significantly better than SAR data in terms of data sources. The combination of optical and SAR data could improve the accuracy of mangrove mapping to a certain extent (0.33% to 4.67%), which is essential for the research of mangrove mapping in a larger area. The XGBoost classification model performed optimally in mangrove mapping, with the highest overall accuracy of 95.00% among all the classification models. The results of the study show that combining optical and SAR remote sensing data with the ERT feature selection method and XGBoost classification model has great potential for accurate mangrove mapping at a regional scale, which is important for mangrove restoration and protection and provides a reliable database for mangrove scientific management.

Determination of Health Index Classification and Management Sustainable Mangrove Ecosystems Using a Combination of Fuzzy and ISM Methods

The area of mangrove forests in Indonesia in 2021, according to the Ministry of Environment and Forestry, is around 3,364,080 Ha; this amount is equivalent to 23% of the world’s mangrove ecosystem, which is from a total of 16,530,000 Ha (FAO, 2005). Information on the condition of mangrove ecosystems is important to know whether or not an area is good. Studies related to the condition of mangrove ecosystems based on environmental quality and mangrove health index to determine the environmental quality and mangrove health are needed for ecosystem management in the future. This article describes the health parameters of mangrove ecosystems that will be analyzed with the help of a combination of decision support software such as fuzzy and ISM so that priority mangrove ecosystem locations can be determined, mangrove health index values to determine the health status of mangrove ecosystems and determine alternative sustainable mangrove ecosystem management policies that will be applied to the object of study. In addition, the study also discusses the concept of determining standard criteria for the level of damage to mangrove ecosystems and determining the status of mangrove ecosystems. Based on fuzzy logic, data analysis shows that the output of the Mangrove Health Index can be determined with 3 variables and 27 rules, with key factors in Mangrove Density, Canopy Cover and Number of saplings. The results of ISM show that management institutions that must be actively involved in supporting the success of sustainable mangrove forest ecosystem management in Batam City are KLHK, DLHK Riau Islands Province, and BPDAS Sei Jang Duriangkang. Proper handling of constraints and management institutions that are actively involved in mangrove forest ecosystem management will ultimately encourage budget effectiveness and efficiency to meet the main goal, namely sustainable mangrove forest ecosystem management in Batam City.

Mangrove Ecosystem Management Strategy In Biringkassi Mangrove Area Pangkep Regency

The mangrove ecosystem has an important role in the balance of the coastal area and the living things that surround it. The magnitude of the role of the mangrove ecosystem as a multifunctional resource and its existence which is very vulnerable to pressure requires a mangrove ecosystem management by integrating all aspects so that the existence of the mangrove ecosystem can be managed and its sustainability can be increased. This study aims to assess the condition and potential of mangrove forests in the Biringkassi mangrove area and determine sustainable management strategies for mangrove ecosystems based on influencing factors. This study uses an ecological analysis of mangrove ecosystems and SWOT analysis to determine sustainable management strategies. The results showed that the identification of Biringkassi mangroves in the three sample areas found 3 families of 3 species, Rhizopora mucronata, Sonneratia alba, And Avicennia alba. The type of Rhizopora mucronata had the highest density among all species found at 3 sample locations. The total density is 293 ind./hectare. Management strategies that are a priority in sustainable management of the Biringkassi mangrove area are: Developing a mangrove data bank through cooperation with the government, communities, and NGOs, strengthening institutional coordination that is more measurable and structured in the context of ecological sustainability, through conservation the establishment and arrangement of the Biringkassi mangrove management area, developing community-based management such as nursery and ecotourism management, improving the quality of human resources and maximizing the role of the community local communities in maintaining mangroves. The condition of the density of the Biringkassi mangrove ecosystem is categorized as less dense.

Molecular barcoding of the Persian Gulf mangrove associated brachyuran crabs

Brachyuran crabs constitute the dominant fauna in intertidal and supratidal coasts of mangrove forests. We sampled the most commonly occurring crab species from the biodiversity rich Persian Gulf mangrove forest. We identified crabs from Camptandriidae, Dotillidae, Ocypodidae, Macrophthalmidae, and Sesarmidae as the most common species in the sampled regions. Molecular barcoding was applied to determine 11 species (29 specimens) of the mangrove crabs. Two mitochondrial genes were used to barcode the specimens and these were included in a larger phylogenetic data set. Many of the analyzed species showed a close phylogenetic relationship with species from the Northern Arabian Sea. The results provide the first steps to study the genetic diversity of the mangrove crab community along the Iranian coasts to support protection and management of mangrove ecosystems and its associated taxa.

Carrying capacity of mangrove ecotourism area in Pantai Indah Kapuk, North Jakarta, Indonesia

Abstract. Ewaldo K, Karuniasa M, Takarina ND. 2023. Carrying capacity of mangrove ecotourism area in Pantai Indah Kapuk, North Jakarta, Indonesia. Biodiversitas 24: 5809-5820. Mangroves are crucial in providing various ecological and economic benefits to local communities. This study focuses on the economic aspect of mangroves by analyzing their potential as a tourist attraction in the Mangrove Ecotourism, Pantai Indah Kapuk (PIK). The objective of this study is to analyze the carrying capacity of the mangroves as a tourist attraction to ensure sustainable tourism development. The study was conducted in the Mangrove Ecotourism area, Pantai Indah Kapuk, from January to March 2023, utilizing a quantitative approach. The carrying capacity of the mangrove ecosystem was assessed using the Physical Carrying Capacity (PCC), Real Carrying Capacity (RCC), and Effective Carrying Capacity (ECC) methods. The calculated values for PCC, RCC, and ECC were 107, 16, and 313 visitors/day, respectively. The analysis revealed that the number of visitors at the PIK Mangrove Ecotourism in 2022 had exceeded the PCC and RCC limits, indicating potential ecological impacts. However, the number of visitors had remained within the ECC limits, suggesting that with proper management, the site could accommodate the current visitor levels sustainably. To achieve long-term sustainability, several initiatives are recommended, such as creating zoning in tourist areas to distribute visitor pressure, increasing the number of field officers to monitor the site, and implementing an online ordering system to manage visitor flow efficiently. The findings of this study contribute to the understanding of the carrying capacity concept in ecotourism and provide valuable insights for the management and conservation of mangrove ecosystems as tourist attractions.

Using Multisource High-Resolution Remote Sensing Data (2 m) with a Habitat–Tide–Semantic Segmentation Approach for Mangrove Mapping

Mangrove wetlands are hotspots of global biodiversity and blue carbon reserves in coastal wetlands, with unique ecological functions and significant socioeconomic value. Annual fine-scale monitoring of mangroves is crucial for evaluating national conservation programs and implementing sustainable mangrove management strategies. However, annual fine-scale mapping of mangroves over large areas using remote sensing remains a challenge due to spectral similarities with coastal vegetation, tidal periodic fluctuations, and the need for consistent and dependable samples across different years. In previous research, there has been a lack of strategies that simultaneously consider spatial, temporal, and methodological aspects of mangrove extraction. Therefore, based on an approach that considers mangrove habitat, tides, and a semantic segmentation approach, we propose a method for fine-scale mangrove mapping suitable for long time-series data. This is an optimized hybrid model that integrates spatial, temporal, and methodological considerations. The model uses five sensors (GF-1, GF-2, GF-6, ZY-301, ZY-302) to combine deep learning U-Net models with mangrove habitat information and algorithms during low-tide periods. This method produces a mangrove map with a spatial resolution of 2 m. We applied this algorithm to three typical mangrove regions in the Beibu Gulf of Guangxi Province. The results showed the following: (1) The model scored above 0.9 in terms of its F1-score in all three study areas at the time of training, with an average accuracy of 92.54% for mangrove extraction. (2) The average overall accuracy (OA) for the extraction of mangrove distribution in three typical areas in the Beibu Gulf was 93.29%. When comparing the validation of different regions and years, the overall OA accuracy exceeded 89.84% and the Kappa coefficient exceeded 0.74. (3) The model results are reliable for extracting sparse and slow-growing young mangroves and narrow mangrove belts along roadsides. In some areas where tidal flooding occurs, the existing dataset underestimates mangrove extraction to a certain extent. The fine-scale mangrove extraction method provides a foundation for the implementation of fine-scale management of mangrove ecosystems, support for species diversity conservation, blue carbon recovery, and sustainable development goals related to coastal development.

The nexus between stakeholders’ role, eco-empowerment, and community perceptions on mangrove ecosystem management’s sustainability

Managing coastal ecosystem resources and mangrove forests in Sayung District, Demak Regency faces many challenges if it does not involve the community’s active role and stakeholders. Ecological empowerment faces the abrasion, erosion, and sedimentation of coastal areas that mangrove stands have not covered. On the other hand, the revitalization and rehabilitation program is still not optimal, so it requires the participation of many institutions, not only from the government but also from non-government, so that all management programs run in tandem are integrated and is following regulations. This study aims to determine the relationship between the role of stakeholders, eco-empowerment, and community perceptions of the sustainability of mangrove ecosystem management. The location selection used the purposive method. While the sample selection used the purposive and snowball random sampling methods. Data analysis used the partial least square method. The study’s results indicate that the stakeholders’ role has a direct positive and significant impact on eco-empowerment and perceptions of sustainability. Eco-empowerment has a direct positive and significant effect on the perception of sustainability. The role of stakeholders has a positive and indirect influence on the perception of sustainability through eco-empowerment activities.

Analysis of mangrove dynamics and its protection effect in the Guangdong-Hong Kong-Macao Coastal Area based on the Google Earth Engine platform

Mangroves are rapidly disappearing in several places of the world, and mangrove dynamics are becoming important evidence of ecological restoration and protection along the coast. Mangrove populations in the Guangdong-Hong Kong-Macao Coastal Area (GCA) have experienced a substantial impact of anthropogenic pressure in the 20th century. Monitoring its spatio-temporal variation and protection effect has been regarded as an important task in coastal management. In this study, we provided the comprehensive assessment of mangrove dynamics in the GCA and typical sites from 1988 to 2020 at eight-year intervals. At this time interval, mangrove ecosystems changed significantly as a result of global warming and human impacts. The geographical distribution of mangroves was obtained by applying the Random Forest (RF) classifier on Landsat images with a 30 m spatial resolution on the Google Earth Engine (GEE) platform, based on relevant indices such as Normalized Difference Mangrove Index (NDMI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Suspended Sediment Index (NDSSI), Normalized Difference Built-up Index (NDBI) and Soil Adjusted Vegetation Index (SAVI). Quantitative evaluation indicated that overall accuracy of over 88% was achieved with RF classifier for mangrove extraction. In the GCA, mangrove area was 95.4 km2 in 1988, dropped to 71.4 km2 in 1996, then expanded to 127.5 km2 in 2020, with an overall dynamic rate of 1.02%. In typical sites, mangroves show a similar trend to the overall area. The subsequent mangrove growth is attributed to reserve establishment, accompanied by the expansion of replanted mangrove areas. In the GCA, provincial-level and county-level reserves show a high rate of mangrove dynamic, while national-level reserves display a low rate of mangrove dynamic. The dynamic rate in reserves of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is higher than other parts of the GCA, indicating that the effect of mangrove protection is better in the GBA. The results of this study will provide scientific foundations for the sustainable management and conservation of mangrove ecosystem, the quantification of ecosystem services (such as coastal protection and carbon storage), as well as the formulation of strategies for mitigating and adapting to climate change.

Length – Weight Relationship of Bivalves and Gastropods from Mangrove Forest of Brgy. Nabago, Surigao City, Philippines

Bivalves and gastropods are among the most important food resource in coastal communities. The destructive ways of harvesting these mangrove associate fauna may cause a threat to the forest and may alter the physiological condition of these organisms. The length-weight relationship of two bivalves (Anodontia edentula and Saccostrea cuccullata) and 11 gastropods (Littoraria angulifera, Littoraria melanostoma, Littoraria scabra, Chicoreus capunicus, Tenguella musiva, Nerita exuvia, Nerita lineata, Cerithidea decollate, Terebralia palustris, and Terebralia sulcata) species collected from the mangrove forest of Barangay Nabago, Surigao City was assessed in this study. A. edentula exhibits positive allometry (b=3.7002) while S. cuccullata shows negative allometry (b=2.6145). The 11 gastropod species demonstrate a negative allometric pattern (b<3). The negative allometric pattern of these species indicates that the length increased faster than the weight, which could be attributed to the different environmental factors in the area. The data obtained in this study is essential for the monitoring of these organisms and management of the entire mangrove ecosystem in the area.

Mangrove Ecosystem Management for Sustainable Renewable Energy Production: A Multi-Dimensional Analysis

Mangrove ecosystems have become a critical habitat for sustaining renewable energy production, and their management is essential to maintain their ecological, economic, and social functions. This study aimed to analyze the multidimensional aspects of mangrove ecosystem management for sustainable renewable energy production in the Tebing Tinggi, Kepulauan Meranti, Riau. This study formulates sustainable management schemes for the mangrove ecosystem in the Tebing Tinggi, Kepulauan Meranti, Riau by analyzing the ecological, economic, social, legal-institutional, and technological aspects of the ecosystem. To conduct this analysis, researchers used the Multidimensional Scaling (MDS) approach, which relies on an algorithm called the MDS algorithm. The findings from the study reveal that the use of mangroves can increase people's income, but the level of community education is still low, and there is a lack of community participation in mangrove ecosystem management activities. Based on the Rap-Mangrove analysis, the multidimensional index of mangrove ecosystem management is considered sufficiently sustainable. The findings emphasized the significance of community participation and education in managing mangrove ecosystems. The study concludes that sustainable management schemes for mangrove ecosystems are necessary to ensure their continued contribution to renewable energy production.