A baseline study of the diversity and community ecology of crab and molluscan macrofauna in the Sematan mangrove forest, Sarawak, Malaysia

Mangrove forests are among the world’s most productive ecosystems situated at the interface between land and sea/backwaters in tropical and subtropical latitudes. Mangrove vegetation in three geographical regions of Kannur on the southwest coast of India was assessed for its community structure and diversity indices. Thirteen true mangrove species belonging to 9 genera and 7 families formed the mangrove vegetation of the region. Highest density was recorded for Acanthus ilicifolius (7953 stems/ha), followed by Rhizophora mucronata (3750 stems/ha). A. ilicifolius is the most common species with maximum important value index (IVI) of 49.19. Shannon-Weiner Index of diversity ranged from 2.249 to 2.527. Kunhimangalam region have more species richness with a Simpson dominance index of 0.920 and Shannon - Weiner index of 2.527. The sites selected were distinct from each other as the species diversity varied due to the climatic, biotic, anthropogenic stresses at each location. The need to gain further knowledge about the mangrove flora of the region to help the conservation of mangrove ecosystems is highlighted.

Mangrove Rehabilitation and Intertidal Biodiversity: a Study in the Ranong Mangrove Ecosystem, Thailand

Governance issues related to the management and conservation of mangrove ecosystems to support climate change mitigation actions in Indonesia

Gastropods are marine biota found in the waters of Pulau Terkulai, Tanjungpinang City and are one of the catch of fishermen. However, information on the structure of the gastropod community in these waters is not widely known. The purpose of this study was to determine the types of gastropods, gastropod community structure, and the relationship between gastropod community structure and environmental parameters in the waters of Terkulai Island. This research was conducted in April-August 2023. Determination of sampling points using random sampling method as many as 30 points with sampling plots measuring 1x1m2. The results of this study obtained 650 individuals with 15 species of gastropods. The highest density was found in Batillaria attramentaria species with a total of 12.20 ind/m2. Gastropod community structure diversity value (H') ranged from 1.512 which is classified as moderate. The uniformity value (E) ranges from 0.558 which is classified as moderate and the dominance value (D) ranges from 0.353 which is classified as moderate. The results of the measurement of the physicochemical parameters of the waters are still at a feasible threshold for gastropod life. The principal component analysis (PCA) shows that the density with water parameters has a positive correlation with temperature and organic matter.

A study of epiphytic gastropods associated with two submerged macrophytes (Myriophyllum spicatum and Vallisneria americana) was conducted at a soft and at a hard water site in the St. Lawrence River during two non-consecutive years in order to compare effects of macrophyte species and biomass, site and year in gastropod community structure. There was no effect of macrophyte species on total gastropod abundance nor on gastropod diversity, and few gastropod species showed a marked preference for either macrophyte species. Inter-site and inter-annual variations in diversity, total gastropod abundance and gastropod community structure were greater than variations among macrophytes. However, analysis of variations of epiphytic gastropod communities in one of the two sites shows that abiotic factors are important in explaining epiphytic gastropod distribution. Our results and results of other studies on gastropod population dynamics in the St. Lawrence River indicate that intra- and interspecific competition between gastropods is important on macrophytes and that they must be carefully considered in order to understand epiphytic community structure and population dynamics.

Mangrove ecosystem in the Segara Anakan (SA) has a high diverse vegetation. However this ecosystem acreage has been shrinking continues due to sedimentation and people intervention. A set of policies, including institutional development has been set up and implemented but these policies have not achieved their target goals. Weak community participation in the management of the ecosystem was due to low education level and welfare of the community in this area, limited community empowerment programs, and weak social institution arrangements. This condition causes continuation of encroachment and land-use changes of the mangrove ecosystem by the community. This research used a qualitative approach and its aims to analysis to what degree the community role has played and what policy option should be taken to strengthen the community role in the SA lagoon. Results of this study indicated that the existence of complexity problems of authorities arrangement between central and local governments, socio-cultural system, and frequent changes of officers in this mangrove ecosystem conservation have made some degree of difficulty to solve the problem. Policy alternatives recommended from this research in order to improve community role in this mangrove ecosystem management are empowerment of community role such as affirmative policy for the SA ecosystem management, empowerment of public and social institution on conservation activities, development of the lagoon as an ecotourism area with faster rate, and strengthening efforts to promote the importance of the mangrove ecosystem for the young generation in the surrounding SA Lagoon areas.

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.

Mangrove ecosystem valuation can be used as a reference for decision making for management and conservation of mangrove ecosystems in a sustainable manner. The range of activities and interests conducted in coastal areas is not expected to negatively impact the ecology, economic and social. Carat Cape mangrove areas provide enormous benefits to the surrounding community, especially Sungsang IV village. From the results of the study illustrate the provosioning ecosystem service utilized community Sungsang IV village consists of materials construction (timber and nypa leaves), a source of livelihood or subsistance (nypa fruit, fish, shrimp, crab, and scallops). The total value of provosioning ecosystem services mangrove Carat Cape utilized by the Sungsang IV village Rp. Rp. 1.715.590.000, - per year dominated by income generated by marine species of fish which is the main livelihood of the fishermen Sungsang IV village reached Rp. 1.302.600.000,- per year.

Bali is an island situated among the Indonesian archipelago with huge potential to host mangrove forests. Using remote sensing technology advances, satellite images, such as Landsat images, might be employed to analyse mangrove forest distribution and density. This paper presents an analysis of mangrove distribution in Badung Regency and Denpasar City, Bali, as a basis for the management and conservation of mangrove ecosystems. This study used Landsat 8 OLI images and a vegetation index to analyse the mangrove forest distribution and density in this area. It started by identifying mangrove forests using the RGB 564 band and continued to distinguish between mangrove and non-mangrove objects using unsupervised classification, before analysing mangrove density using the NDVI formula. The results show that the mangrove forest area in 2020 was 1,269.20 ha, with an accuracy rate of 83%. Mangroves were found on the deepest or most curved coastline of the Benoa Bay area, on enclosed waters. This distribution follows the river network in the lower reach, which has thick deposits and is uninfluenced by large currents and waves. Based on the vegetation index analysis results, the mangrove forest area observed mainly had a moderate density, with a total area of 510.85 ha (40%), followed by high density (413.15 ha/ 33%) and low density (340.51 ha/ 27%).

Crabs appear as the most important group of mangrove epifauna. Their distribution seems influenced by some biotic and abiotic parameters. To verify the interactions between crab populations and relevant environmental components, six mangrove sites around the city of Douala (3°40' - 4°11'N and 9°16' - 9°52'E) were selected. During six months, four 25-min independent time-biased samples methods were conducted in the plot of 4 × 4 m2 delimited inside each zonation throughout transect. The distance from plot to water and its groundwater salinity, temperature, conductivity and pH were measured. The individual sex, fresh weight and carapace size were determined. 3016 individuals were harvested (57% of females). Perisesarma kamermani was the most abundant (29%) while Chiromates angolense was the most frequent (13.47%). Cardisoma armatum was only found in Pandanus zone. Crab species number was positively correlated with tree, suggesting that the mangrove vegetation is important to the crab fauna as a habitat and food supply. Sex ratio showed a significant difference for Chiromates buetikoferi 1:2.34 (χ2 = 33.21) and for Perisesarma huzardi 1.36:1 (χ2 = 39.98). Portunus validus live closer to water between 5 - 20 m while Cardisoma armatum was found 70 m away from water. Portunus validus was present exclusively in high salinity zones whereas Perisesarma kamermani dominate in low salinity zone. This baseline ecological study of crab mangroves is important for monitoring, management and conservation of mangrove ecosystems.

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.

The objective of this research is to designed and developed a system known as Mangrove Simulation: Attenuation of Storm Surges in Protecting Coastal Area and Geospatial Simulation Model of Mangrove Forest in Palsabangon Mangrove Swamp Forest Reserve Pagbilao, Quezon. The system incorporates various functionalities including web-based application and geographical information system for administrator and staff of Palsabangon Mangrove Swamp Forest Reserve. To utilize the Agent-Based model that simulate and predict the growth and spatial distribution of various mangrove species with regards to the environment. To evaluate of the accuracy of the algorithm in mangrove simulation with geographic information system mapping aims to improve they understanding of the ecological dynamics and spatial patterns of mangroves, and provide useful information for the management and conservation of mangrove ecosystems. The system underwent a comprehensive testing process to assess its functionality, suitability, reliability, performance efficiency, operability, security, compatibility, and maintainability. The results revealed that the system achieved an overall mean score of 4.09, indicating a "Very Satisfactory" rating. This signifies that both experts and clients were very satisfied with the system's characteristics. Moreover, it passed on the standard rating level of ISO/IEC 25010. This remark indicates that the system performed effectively and achieved its goals.

The purposes of the present study were to analyze the community structure of gastropods and bivalves as well as to analyze the relationship between the abundance of gastropods and bivalves within mangrove density in Pusung Cium Island, Seruway, Aceh Tamiang Regency. The research was conducted from October to November 2019. The method used in determining the location of the research station was Stratified Random Sampling based on the density of mangrove vegetation, the station 1st, 2nd, 3rd were dense, medium, and rare categories, respectively. There were 4.67 ind/m2 consisted of 3 species for bivalves class and 143.33 ind/m2 species of gastropods class consisted of 41 species. The highest abundance was in station three, and the highest gastropods species abundance was Littorina angulifera (51.33 ind / m2) and Saccostrea cucculata (1.33 ind / m2) for bivalves class. Biological indices showed that the diversity index of gastropods and bivalves was high and ranged from 4.24 to 2.35, evenness and dominance indices were ranged from 0.44 to 0.79 and 0.20 to 0.21. Furthermore, the distribution pattern of gastropods and bivalves were uniform, random, and clumped. The correlation between the density of mangrove and abundance of gastropods-bivalves was weak and moderate and there was no significant correlation between the density of mangrove and abundance of biota aquatic (gastropods and bivalves) where Psig > 0.05. In conclusion, the community structure of gastropods and bivalves was in stable condition showed by high diversity index, moderate evenness index, and low dominance index.

We investigated the community structure of ectomycorrhizal fungi under varying overstory tree compositions in the southern mixed-wood boreal forest of Quebec. Sampling took place at two locations of differing postfire ages and nine 100-m2 plots were sampled per location. The dominant overstory tree species in the plots were trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.) or white spruce [Picea glauca (Moench) Voss], and balsam fir [Abies balsamea (L.) Mill.]. Mycorrhizae were analyzed using morphological as well as molecular methods, employing fungal-specific primers to amplify ribosomal DNA for subsequent cloning and sequencing. A total of 1800 mycorrhizal root tips collected from the 18 plots were morphologically classified into 26 morphotypes, with Cenococcum geophilum dominating (36% of root tips). A second set of root tips, selected from the same 18 samples on which the morphological analysis was based, were analyzed using molecular methods. From this analysis, 576 cloned polymerase chain reaction products were screened by restriction fragment length polymorphism analysis and a total of 207 unique types were found. No one type dominated the system and 159 occurred only once. Sequence analysis of the types that occurred more than once revealed that Piloderma sp., Russula sp., Cortinarius sp., and Lactarius sp. were the most common mycorrhizae. The ectomycorrhizal fungal community structure revealed by the rDNA analysis differed from that observed using morphological methods. Canonical correspondence analyses of the sequenced restriction types and % overstory composition indicate that the distributions of ectomycorrhizal fungi are influenced by the relative proportions of host tree species. The distinct fungal assemblages found in the different plots supported by the different combinations of host tree species provides further support for the need to conserve stand diversity in the southern boreal forest.

Transitions in Ancient Inland Freshwater Resource Management in Sri Lanka Affect Biota and Human Populations in and around Coastal Lagoons