Mangrove Area Research Articles

Abundance and Distribution Patterns of Oysters (Saccostrea cucullata) in the Bagek Kembar Mangrove Area, West Lombok

An invertebrate critter called Saccostrea cucullata is typically found adhering to substrates like rocks and mangrove roots. The purpose of this study is to ascertain S. cucullata's abundance and distribution patterns. This study was carried out at West Lombok's Bagek Kembar Sekotong Natural Mangrove Area in February 2024. The samples were observed using the 5 x 5 m quadratic transect approach. To ascertain S. cucullata abundance and dispersion patterns, descriptive analysis was performed on the data. According to the study's findings, station I had the greatest abundance (1.81 Ind/m2), while station III had the lowest (0.95 Ind/m2). S. cucullata exhibits a clustered and uniform distribution pattern in certain areas. In the research region, temperature, salinity, and pH are the main factors affecting S. cucullata abundance and dispersion pattern, respectively.

A new species of Malacoceros (Annelida, Polychaeta, Canalipalpata, Spionidae) from urban waters in Gabon

A new species of Malacoceros is described from estuarine equatorial waters in Libreville (Gabon, West Africa). During a recent environmental study aimed to assess the urban impact on an estuarine ecosystem near Libreville, the collection of sediment samples from the area was undertaken. The local invertebrate macrofauna had not been previously well studied, and to document the biodiversity, specimens were examined in more detail. A new species of Malacoceros was discovered, occurring in mangrove areas. The new species is described and illustrated in detail, and information on three molecular markers was retrieved and partially used for species delimitation analysis. The new species resembles Malacoceros indicus (Fauvel 1928) described from India but is easily distinguished by a very conspicuous morphological character, the presence of 7–11 large tubercles along the anterior margin of the prostomium. The presence of such conspicuous tubercles has never been observed before in Malacoceros. Maximum likelihood trees for species of Malacoceros and the close genera of Rhynchospio, for which we have data, are also provided. The suitability of characters used for species delimitation in Malacoceros is discussed.

Spatial Distribution of Mangrove Density in Gili Gede, West Lombok Regency

Gili Gede hosts a vital mangrove ecosystem, essential for the community and protecting coastal areas from large waves. However, increasing development and human activities in and around the mangrove areas threaten their distribution and extent. This study aims to map the spatial distribution, density, and area of mangroves on Gili Gede. Sentinel-2A satellite imagery was utilized with the Normalized Difference Vegetation Index (NDVI) method, and the image data were validated using hemispherical photography. Environmental parameters measured included sediment salinity, temperature, pH, humidity, NPK nutrients, and substrate type. Additional data were gathered on slope, buffer distances, and through semi-structured interviews using purposive sampling. The findings revealed that the mangrove density on Gili Gede is predominantly sparse, covering 15.56 hectares or 77.07% of the total mangrove area. Medium-density mangroves span 3.45 hectares or 17.09%, while dense mangroves occupy the smallest area, 1.18 hectares or 5.84%. Mangroves are distributed across the northern, western, and eastern sides of Gili Gede. The study identified 22 species of mangroves, both true and associated, across 14 families. Environmental factors influencing the distribution, density, and extent of mangroves across three locations include sediment salinity, temperature, pH, humidity, and nutrient content (NPK), as well as substrate type, slope, and anthropogenic influences such as human activities and the proximity of settlements to the mangrove ecosystem.

Pengelolaan Permukiman Pesisir dan di Atas Air Berkelanjutan di Desa Teluk Sunting, Kabupaten Kepulauan Anambas Provinsi Kepulauan Riau

Coastal settlements are highly vulnerable because they are greatly affected by global climate change. Population growth will further increase the use of unorganized built space in the coastal area of Teluk Sunting Village which in the future could lead to conflict as a result of regulations and policies regarding coastal areas. This research was conducted in the coastal residential area of Teluk Sunting Village, Central Siantan District, Anambas Islands Regency. The research method consists of data collection techniques, sampling techniques, data requirements, data presentation, analysis methods and data analysis techniques. The results obtained are that the administrative area of Teluk Sunting Village contains cultivation and protected areas according to the RTRW Spatial Pattern Plan. The area is 5.29 Ha of mangrove ecosystem area and 34.83 Ha of protected forest area. Area of 19.22 Ha cultivation area. The environmental quality results obtained in RT 1 settlements are low quality settlements, RT 3 is medium quality settlements and RT 2 and RT 4 settlements are high quality settlements. The conclusions obtained from the four approaches taken to identify land use patterns, namely land use patterns, land use and use with land tenure, conformity with the RTRW and conformity with the zoning of Aquatic Tourism Parks, are in accordance with the designation. The involvement of stakeholders in the management of coastal and water areas in Teluk Sunting Village is very appropriate to support and ensure the sustainability of the area in the future.

Semi-automated mangrove mapping at National-Scale using Sentinel-2, Sentinel-1, and SRTM data with Google Earth Engine: A case study in Thailand

Mangroves are a crucial part of the coastal ecosystem; thus, precise and up-to-date monitoring is essential to guide regional policies and inform conservation strategies. This study investigates the capabilities of semi-automated remote sensing approaches within a Google Earth Engine framework for national-scale mangrove mapping in Thailand. Remote sensing data from 2018—10,000 data points acquired from Sentinel-1, Sentinel-2, and the Shuttle Radar Topography Mission (SRTM)—was used to train several machine learning models. The Gradient Tree Boost (GTB) proved to be the most reliable, with the least variation in validity (the lowest IQR) and the highest average Overall Accuracy of 96.75 ± 0.63 % compared to the others—96.64 ± 0.72 % for Random Forest (RF); 96.12 ± 0.80 %for Classification and Regression Trees (CART); and 95.43 ± 0.74 % for Support Vector Machines (SVM). Thus, the GTB was instrumental in mapping mangrove distribution with 10-m spatial resolution across Thailand from 2016 to 2022, the period in which the mangrove areas increased by 11 %, reflecting successful conservation efforts over the past decade. The developed framework establishes the foundation for semi-automated mangrove mapping that can be developed for other geographical contexts.

Circulation in a tropical embayment with two inlets and complex geometry: The Itamaracá-Itapessoca system, Brazil

Along the northeast coast of Brazil, numerous estuaries with intricate morphologies, characterized by multiple channels, islands, and intertidal areas, are found. These estuaries undergo significant seasonal variations, experiencing pronounced wet and dry periods. While some of these systems have small drainage basins with minimal freshwater inflow and sediment production, they boast extensive intertidal mangrove areas. This study focuses on assessing the hydrodynamics and residual circulation of the Itamaracá-Itapessoca Estuarine System (IIES) to elucidate the impact of residual circulation on estuary-shelf exchange dynamics. The IIES comprises two main islands and two inlets surrounded by extensive intertidal areas. Field observations collected during the wet season were used to calibrate and validate a numerical model. Two model scenarios were examined: a 'dry' scenario, considering hydrodynamics driven solely by interactions between morphology and tides, and a 'wet' scenario, incorporating freshwater inflow. Key findings include: (a) the inclusion of freshwater inflow minimally alters system dynamics; (b) tidal dynamics are amplified within the system, resulting in a null zone between the inlets; and (c) residual circulation circulates around the islands, with net importation through the larger inlet and net exportation through the smaller one. The intensity of exchange is heightened under wet conditions.

Assessing changes in land cover, NDVI, and LST in the Sundarbans mangrove forest in Bangladesh and India: A GIS and remote sensing approach

Mangrove ecosystems, although limited in diversity and area compared to tropical forests, provide essential ecological and economic services, such as carbon sequestration and coastal protection. The Sundarbans mangrove forest, shared by Bangladesh and India, is one of the largest mangrove ecosystems in the world and is crucial for biodiversity, economy, and climate regulation. Unfortunately, this ecosystem has been under severe stress over the years, with alarming rates of deforestation leading to habitat loss and a decline in ecosystem services. This study analyzes the spatiotemporal changes in the Sundarbans mangrove forest coverage from 1973 to 2023 using supervised image classification on Landsat images. It also assesses the relationship between the Normalized Difference Vegetation Index and Land Surface Temperature in the Sundarbans using MODIS data which were extracted in Google Earth Engine. It finds that, despite the loss of denser mangrove areas, an improvement in overall vegetation health is visible, which suggests a natural resilience within the Sundarbans mangrove forest. The Land Surface Temperature result shows a weak but statistically significant negative correlation with the Normalized Difference Vegetation Index, indicating that the depletion of the Sundarbans mangrove forest could have an impact on the area's surface temperature. As such, the study regressed the Normalized Difference Vegetation Index on Land Surface Temperature. The results confirm that although the Normalized Difference Vegetation Index has a statistically significant negative impact on Land Surface Temperature, the Coefficient of Determination is low. This suggests that other factors such as water bodies that intersect with the mangrove forest in the area may play an important role in influencing Land Surface Temperature. The paper reveals a nuanced picture of the Sundarbans' ecological state, with both declining mangrove densities and signs of vegetation recovery. It highlights the need for comprehensive conservation strategies to mitigate further ecosystem degradation.

Isolation of Alpha-Glucosidase Inhibitors from the Panamanian Mangrove Plant Mora oleifera (Triana ex Hemsl.) Ducke.

Panama boasts an expansive mangrove area and stands as one of the most biodiverse countries in America. While mangrove plants have long been utilized in traditional medicine, there are still unstudied species whose potential medicinal applications remain unknown. This study aimed to extract bioactive compounds from Mora oleifera (Triana ex Hemsl.) Ducke, an understudied mangrove species. Through bioassay-guided fractionation of the crude extract, we isolated seven active compounds identified as lupenone (1), lupeol (2), α-amyrin (3), β-amyrin (4), palmitic acid (5), sitosterol (6), and stigmasterol (7). Compound structures were determined using spectroscopic analyses, including APCI-HR-MS and NMR. Compounds 1-7 displayed concentration-dependent inhibition of the alpha-glucosidase enzyme, with IC50 values of 0.72, 1.05, 2.13, 1.22, 240.20, 18.70, and 163.10 µM, respectively. Their inhibitory activity surpassed acarbose, the positive control (IC50 241.6 µM). Kinetic analysis revealed that all compounds acted as competitive inhibitors. Docking analysis predicted that all triterpenes bonded to the same site as acarbose in human intestinal alpha-glucosidase (PDB: 3TOP). A complementary metabolomic analysis of M. oleifera active fractions revealed the presence of 64 compounds, shedding new light on the plant's chemical composition. These findings suggest that M. oleifera holds promise as a valuable botanical source for developing compounds for managing blood sugar levels in individuals with diabetes.

Mangrove Cover and Extent of Protection Influence Lateral Erosion Control at Hybrid Mangrove Living Shorelines

Erosion poses a significant threat to coastal and estuarine environments worldwide and is further exacerbated by anthropogenic activities and increasing coastal hazards. While conventional engineered structures, such as seawalls and revetments, are commonly employed to protect shorelines from wave impact and erosion, they can also cause detrimental environmental effects. By creating/restoring coastal habitats with engineered structures, hybrid living shorelines offer coastal protection and other co-benefits. Using aerial imagery, we studied the rates of shoreline change before and after living shoreline installation, and between living shorelines and adjacent bare shorelines in three estuaries in New South Wales, Australia. Mangroves had established behind most rock fillets and displayed a trend of increasing canopy cover with fillet age. In the first 3 years since installation, the rates of lateral shoreline change reduced from − 0.20, − 0.16, and − 0.10 m/year to − 0.03, − 0.01, and 0.06 m/year in living shorelines in Hunter, Manning, and Richmond Rivers, respectively. However, when compared to control shorelines, the effectiveness in reducing erosion varied among living shorelines with mean effect sizes of 0.04, − 0.28, and 1.74 across the three estuaries. A more positive rate of shoreline change was associated with an increasing percentage of mangrove canopy area and an increasing length of protected shoreline at wide channels. While hybrid mangrove living shorelines are a promising solution for mitigating erosion and creating habitats at an estuary-wide scale, they may also contribute to downdrift erosion, emphasising the importance of considering site-specific hydrogeomorphology and sediment movement when installing living shorelines.

USG matrix analysis and power interest to improve community environmental awareness: A case study of mangrove land cover to support community and environmental education

This study employed a mixed-method approach to analyze the composition of mangrove forests. The transect method and remote sensing through supervised classification using Google Earth Engine (GEE) were utilized to assess changes in mangrove areas in 2017, 2019, and 2021. The findings suggest that this study should be included in population and environmental education courses. The results revealed that Avicennia marina mangroves had the highest importance index (INP) values at three different locations. Between 2017 and 2019, mangrove areas decreased from 30.62 hectares to 27.98 hectares. However, from 2019 to 2021, the mangrove area increased from 27.98 hectares to 29.18 hectares, largely due to reforestation efforts in the Pulau Dua Nature Reserve. The NDVI (Normalized Difference Vegetation Index) values indicated "bushy" criteria, ranging from 0.43 to 1.00. The Normalized Difference Mangrove Index (NDMI) values fell into the "Rare" (-1.00 to 0.32) and "Medium" (0.33 to 0.43) categories. The Urgency, Seriousness, and Growth (USG) matrix analysis and Power Interest assessment identified illegal logging, erosion, and waste as significant causes of mangrove decline. Stakeholders, including village chiefs, religious leaders, traditional leaders, and youth leaders, must focus on preserving the mangrove ecosystem in the CAPD. The study's results are vital for educational purposes, particularly in population and environmental education courses. These courses should address environmental issues, prevention strategies, and conservation activities, which can be integrated into the curriculum. This will enable youth to contribute effectively to environmental awareness programs.

ANALYSIS OF MANGROVE DAMAGE AND DIVERSITY IN THE MANGROVE FOREST AREA OF TANJUNG SOLOK VILLAGE, KUALA JAMBI SUB-DISTRICT

Mangrove forests are tropical coastal vegetation communities consisting of several species that are able to grow and develop in muddy tidal areas. Coastal areas have a variety of community activities in utilizing coastal natural resources in the economic sector. Social condition factors and lack of understanding of the functions and benefits of mangroves also affect the damage to mangrove ecosystems. This directly causes ecological impacts that threaten the sustainability of mangrove forests. The purpose of this study was to analyze the damage and diversity of mangroves in the mangrove ecosystem area of Tanjung Solok Village. This research method uses indepth interview techniques, and observation in the field with data collection including documentation and sample identification. The results showed that the damage to mangrove ecosystems in Tanjung Solok Village, Kuala Jambi District was categorized as low or damaged, because the results obtained tree density <1000 trees/ha. This is caused by activity factors and lack of knowledge of the surrounding community. As well as the level of diversity (H') obtained in Tanjung Solok Village, Kuala Jambi District, obtained a value of 2.033. This shows that the level of diversity of mangrove vegetation in Tanjung Solok Village, Kuala Jambi Subdistrict is in the medium category. Keyword: Mangrove diversity, coastal ecosystems, mangrove malfunction

Phytoplankton Community Structure in Bun-Bun River Waters, Kubu Raya Regency, West Kalimantan

The Bun-bun River was located in a mangrove forest area in Kubu Raya Regency and empties into the sea. As the main producers at the trophic level of waters, phytoplankton has an important role in assessing river quality. This study aims to find out phytoplankton community structure including abundance, diversity, uniformity, and dominance indexs in relation to Bun-bun River quality. The observations were made in the dry and rainy seasons at three stations starting from the initial end of the mangrove forest (Station 1), the middle (Station 2), and the final end which also empties into the sea (Station 3). Sampling was carried out at three points (left edge, center, right edge). Measurements of physico-chemical factors include brightness, current velocity, temperature, pH, DO, dissolved CO2, salinity, nitrate and phosphate. Phytoplankton sampling used a 30 µm plankton net mesh size and identification down to the species level. The calculated index values include abundance, diversity, uniformity, and dominance. The Bun-bun River was characterized by brackish waters with calm surface currents (<0.1 m.s-1) and a salinity between 5.4-9.48 ppt. Dissolved CO2 levels are relatively high, namely 22-30.8 mg.L-1 in the dry season and 35.2 mg.L-1 in the rainy season. During the dry season, the pH of the water becomes slightly acidic (6.51-6.76) and relatively neutral during the rainy season (7.08-7.52). Nitrate and phosphate levels were low in both seasons and all three stations. The brightness of the water was higher in the dry season than in the rainy season (20-44 cm). A total of 52 types of phytoplankton were found belonging to four classes, namely Class Bacillariophyceae (25 species), Dinophyceae (14), Chlorophyceae (12), and Chrysophyceae (1). Phytoplankton abundance index was low to moderate. The diversity index was moderate at almost all stations except for the low at Station 3 in the rainy season. The uniformity index at Station 3 was low in the dry season but high in the rainy season, and moderate in other locations. The dominance index was high at Station 3 during the dry season and moderate at other locations. Physico-chemical factors such as salinity, dissolved CO2, nitrate and phosphate levels are most likely to influence abundance, while diversity was influenced by dominance.

Population dynamics of spotted scat, Scatophagus argus (Linnaeus 1766) from the Sundarbans of Bangladesh

In Bangladesh, the mangrove areas of the Sundarbans are a hotspot for the spotted scat (Scatophagus argus), as the estuarine tributeries are significant zones for fishing, local marketing and foreign trading. Due to the widespread capture of spotted scats in the wild for a variety of uses, parameters of population were estimated using length-frequency and body weight data gathered from various sites in the southwestern forest areas of the country to comprehend the stock's status. Between May 2022 and April 2023, 1280 S. argus individuals were sampled from Khulna, Bagerhat and Satkhira. To gain insight into the population dynamics of S. argus, estimations of the growth parameters, recruitment pattern, mortalities, and level of exploitation (E) were made. For S. argus, a bit of negetive allomentric growth (b = 2.95) was observed. Moreover, the growth performance index (φ′), the asymptotic length (TL∝) and the growth coefficient (K) were 2.83, 34.65, cm and 0.56 yr−1, respectively. Natural mortality (1.08 yr−1) was lower than fishing mortality (1.12 yr−1). In the wild, this species recruits throughout the year, reaching its peak between October and January. By fishing gear, 50 % of the S. argus were caught between 7.71 cm and 9.43 cm. Moreover, high fishing mortality was assumed in both the small group (11–15 cm) and the large group (29–33 cm) of S. argus by virtual population analysis (VPA). It was discovered that the E for S. argus was 0.51, over the maximum permissible limit (Emax = 0.48). In summary, it is discovered that the S. argus population is overexploited. Therefore, in order to preserve this popular fish species and avoid local extinction, spotted scat resources should be taken into account under appropriate fisheries management guidelines. These findings will guide policymakers to manage the species accordingly.

THE EFFECT OF COASTAL AND CHANNEL MANGROVES SEDIMENT ON BIOTURBATION DISTRIBUTION

Mangroves are a type of tropical tree that thrives and flourishes in harsh conditions where most vegetation struggles. Despite their resilience, mangrove ecosystems face significant threats from deforestation, pollution, and human activities. As an exceptionally efficient habitat for the capture and stabilization of sediment, the mangrove region is also supported by the bioturbation activity where organisms burrow and play an important role in the carbon and nutrient cycle while shaping soil geomorphology within the ecosystem. Many discoveries on the distribution of bioturbation have been carried out in coastal areas regarding grain size, soil density, and others. However, the difference in bioturbation activities on different physical attributes such as coastal, channels, and creeks areas has not yet been well addressed especially in Malaysia. Thus, this study proposes to elucidate the difference in bioturbation distribution between coastal and channel regions in the mangrove areas. The aim is to determine bioturbation distribution within coastal and channel regions by investigating the sediment characteristics and bioturbation frequencies along these two regions. The stratified random quadrat sampling method has been used for bioturbation frequencies, inhabitant species, and population richness. The sediment was characterized with a standard soil dry-sieving method and further analysed by laser diffraction method for fine particle distribution. In examining the effect of physical attribute influence on the bioturbation distribution, a two-way ANOVA assessment was carried out. This study has found that coastal and channel had different sediment distribution and the bioturbation frequencies were influenced by different inhabitants in both regions. Thus, the result of this study supports that coastal and channel regions have significant differences in the bioturbation process. The outcome of this study perhaps will increase awareness among the community members and their involvement in the enrichment and nurturing of ground areas, especially mangrove forests (SDG14).

Karakterisasi dan Identifikasi Rhizobakteri Asal Mangrove Tanjung Pilawang sebagai Biokontrol dan Agen Hayati Pertumbuhan Tanaman

Rhizobacteria are a type of microbe that has an important role in providing nutrients to plants. Rhizobacteria live in symbiosis with plant roots, where their activity has a significant influence on plant growth and development. Various microbes that have the potential to stimulate plant growth are thought to reside in mangrove root areas. The aim of this research is to determine the type of rhizobacteria of the Tanjung Pilawang mangrove, Gura Village, Tobelo District, North Halmahera Regency which is capable of inhibiting the growth of the fungus Collectotricum capsici and dissolving phosphate to be used as a biocontrol and biological agent for plant growth. The research methods used include the isolation stage, selection and characterization stages, and identification stages. The results of the research showed that 11 isolates of rhizobacteria were isolated from Tanjung Pilawang mangrove soil, of these 11 isolates there were two isolates that had the potential to inhibit the growth of the pathogenic fungus Colletotricum capsici and were able to dissolve phosphate, where each isolate was able to provide a Dissolution Index (IP) value. the highest is 2.85 mm and 1.91 mm. After identification, the two isolates were identified as Bacillus subtilis (RTM 10) and Pseudomonas sp (RTM 06), so that these two bacteria have potential as biocontrol and biological agents for plant growth.

Inventarisasi tumbuhan mangrove di Hutan Lindung Tanjung Prapat Muda, Kecamatan Batu Ampar, Kalimantan Barat

Each mangrove ecosystem is diversed which constituted of different vegetations. This also apply for the mangrove area in the Tanjung Prapat Muda Protected Forest, Tanjung Harapan Village, Batu Ampar District. A study of an inventory of mangrove plants was carried out to identify species make up the Tanjung Prapat Muda Protected Forest area. Data collection is conducted alongside the lanes which created by applying the combination of transect and grid lines (transect-plots design). There are 3 lanes with each line consist of 10 plots placed in a zig-zag (right-left) manner. Each plot had sub-plots of different sizes starting from the levels of seedlings (2×2 m), saplings (5×5 m), poles (10×10 m), and trees (20×20 m). Identification was carried out in the field and laboratory. Any unidentified species in the field is documented as herbarium to help identification in the laboratory later. The results shows that there are 7 mangrove species. Five of them are major mangroves (true mangroves), 1 is minor mangrove, and the other 1 are classified as associated mangroves. All the 7 species of plants are belong to 3 families: the Rhizophoraceae, Pteridaceae, and Moraceae families. Five species belong to Rhizophoraceae, namely Rhizophora apiculata, Rhizophora mucronata, Bruguiera gymnorrhiza, Bruguiera parviflora, and Ceriops tagal. The Pteridaceae family consists of one species, namely Acrostichum speciosum, while the Moraceae family only consists of one species, namely Ficus retusa.

An Interdisciplinary Approach to Understand the Resilience of Agrosystems in the Sahel and West Africa

Sub-Saharan African farmers have long been portrayed with very negative representations, at least since the beginning of coordinated European colonialism in the late 19th century. In the Sahel-Sudan area, agrosystems have been described as overgrazed, forests as endangered, and soils as overexploited, with local and traditional “archaic” practices. Against this background, the objective of this article is to focus on these agrosystems’ resilience, for which several criteria have been monitored. The approach used in this research was to synthesize observations from a large amount of material gathered over multiple years by the authors, drawing on our long-term commitment to, and inter-disciplinary study of, the evolution of surface hydrology, ecosystems, and agrosystems of West Africa. The positive trends in rainfall and streamflows, reinforced by farmer’s practices, confirm the overall regreening and reforestation of the Sahel-Sudan strip, especially in areas with high population densities, including the mangrove areas. The intensification of agricultural systems and the recovery of the water-holding capacity of soils and catchments explain the recorded general increase in terms of food self-sufficiency in the Sahel, as well as in crops yields and food production. Finally, we compare the neo-Malthusian discourse to the actual resilience of these agrosystems. The article concludes with a recommendation calling for the empowerment of smallholder farmers to take greater advantage of the current wet period. Overall, the speed of change in knowledge and know-how transfer and implementation, and the farmers’ ability to adapt to ecological and economic crises, must be highlighted. Far from being resistant to change, West African agriculturalists innovate, experiment, borrow, transform, and choose according to their situation, projects, and social issues.

Ecology, distribution, and recruitment of conch (Gastropoda: Strombidae) in intertidal zones

Macroinvertebrates from Family Strombidae locally known as ‘’sikad-sikad’’ are some of the major gleaned species in the intertidal areas. This study investigated the ecology, abundance, distribution, and recruitment of conch species of Family Strombidae in the three coastal barangays (Pandaraonan, Dolores, and Tando) of Guimaras Island. The ecological aspects were assessed for three habitat types (seagrass beds, bare sand, and edges of mangrove areas) within each barangay. A total of 319 conch individuals were identified belonging to seven species (Canarium erythrinum, Canarium labiatum, Canarium mutabile, Canarium urceus, Conomurex luhuanus, Gibberelus gibbosus, and Laevistrombus canarium). The distribution of these species varied across habitats but were found most abundant in Enhalus acoroides and Thalassia hemprichii seagrass beds with patchy distribution exhibited by regular or clumping patterns. Shell lengths ranged from 15–50 mm with C. mutabile being the smallest and C. luhuanus and L. canarium as the largest species. Temporal assessment at one site (i.e., seagrass beds of Dolores) showed no significant variation in the abundance and size of adult conch species across monitoring months. However, conch juveniles assessed showed increasing trend in shell length (5, 8, and 12 mm) but with decreasing density (103, 104, and 90 individuals/m2) from February to April, and June 2023, respectively. This study provides relevant information in the development of policies to ensure sustainability of conch as a valuable fisheries commodity.

PARTISIPASI MASYARAKAT DALAM PENGELOLAAN HUTAN MANGROVE DI DESA BUANO SELATAN KABUPATEN SERAM BAGIAN BARAT

This study aims to determine the form of mangrove forest management and the level of community participation and community supervisory groups in mangrove management in South Buano village. The research was conducted in February - March 2023. Samples were taken using the purposive sampling method and data analysis was carried out descriptively qualitatively and quantitatively. The research results show that the form of mangrove management by the community is carried out based on community knowledge to protect and maintain mangroves. There is a Community Monitoring Group (Pokmaswas) organization that was formed for mangrove management with activities including planning, seeding, maintenance, monitoring and trash cleaning activities in mangrove areas. The level of community participation in mangrove forest management in South Buano village has the highest incentive participation category in seeding, planting and maintenance activities.

Diversity of Gastropods in The Mangrove Forest Area of Ujung Kulon National Park

Various kinds of reseources in coastal areas are very important for us to maintain sustainability. We can find coastal area with varios kinds of ecosystems in Ujung Kulon National Park. This study aims to determine the diversity of gastropods in the mangrove forest area of Ujung Kulon National Park. Sampling used the line transect method and the purposive sampling method with low tide conditions. Sampling was carried out at three stations which are divided into three transects at each station. The transect line was drawn along 50 m with each transect made 5 plots with a size 1 x 1 m2 with a distance between plots of 10 m. This research was held in May-June 2021. The data analysis includes the index values of diversity, dominance, evenness, and abundance. The results of the gastropod obtained consist of 20 species from 7 different families so that diversity index value were included in the medium category with the highest diversity index value owned by station 1 with a diversity index value of 2,03 and the lowest diversity index value owned by station 3 with a value of 1,56. The gastropod abundance index value has an average value of 273 ind/m2.