Condition and level of damage to mangrove ecosystems in Birem Bayeun and Rantau Selamat Districts

Mangrove ecosystem in Segara Anakan Lagoon (SAL) Cilacap as a typical and specific semiclosed estuary. SAL is dominated by many species like as Rhizophora spp., Sonneratia spp., Bruguiera spp., Avicennia spp., and other species. The normalized different vegetation index (NDVI) and dominant vegetation index (DVI) are a suitable method to support the mapping analysis of mangrove structure and mangrove density. This research aimed to develop mapping of mangrove species distribution, density and dominated species using NDVI and DVI. The method of this research used NDVI analysis using satellite imagery 2017-2020 and domination vegetation with line and quadrat transect method. The results showed that West Segara Anakan had mangrove dense (25 %), moderate density (25 %), rare density (50%) and East Segara Anakan had mangrove dense (43,86 %), moderate density (47.99 %), rare density (8,24 %). Based on domination species showed that East Segara Anakan was dominated by Rhizophora stylosa (233-1633 trees ha-1), Rhizophora apiculata (100-1067 trees ha-1), Nypa frutican (50-2775 trees ha-1), whereas West Segara Anakan was dominated by Nypa frutican (565-2333 trees ha-1), Avicennia marina (198-933 trees ha-1), Sonneratia caseolaris (132-700 trees ha-1) and Avicennia alba (107-1000 trees ha-1). Keywords : Mangrove density, mapping analysis, Segara Anakan Lagoon, NDVI and NDWI

Reports indicated a global decline in mangrove forest coverage, with particularly high levels in Sumatera, Indonesia. To effectively conserve these ecosystems, additional research is essential to obtain comprehensive data. Specifically, investigating pollen variation in mangrove species in South Sumatera is critical due to the current lack of information. This study aimed to determine the pollen morphology of various mangrove species in South Sumatera. Fieldwork was conducted around mangrove ecosystem area of Musi Estuary in Tanjung Api-api and Payung Island, South Sumatra. Each mature flower was placed in an envelope and stored an airproof container with silica gel. Herbarium specimens were also used for identification purpose. Pollens of nine mangrove species (Avicennia alba, A. marina, Bruguiera gymnorhiza, B. sexangula, Excoecaria agallocha, Kandelia candel, Nypa fruticans, Rhizophora apiculata, and Sonneratia caseolaris) were observed with a scanning electron microscope (SEM). Pollen SEM images were measured and morphological characteristics of pollens were recorded. The pollen of mangroves in South Sumatera coastal area varied in size (small and medium), ratio of polar/equatorial (prolate, isodiametric and oblate), shape (ellipse, triangular, triangular pyramid and spheroidal shape), polar view (circular, open semi-angular and intruding semi-angular), equatorial view (prolate-circular oval, spherical-apiculate and spherical-circular oval), outline (lobate, triangular and circular), aperture (tricolporate, triporate and monosulcate) and ornamentation (perforate, psilate, echinate reticulate and gemmate). The pollen morphology has been demonstrated to be effective in distinguishing various mangrove species in South Sumatera, and it can be used to produce a species identification key.

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

Mangroves are intertidal plants found along tropical and non-tropical coastlines which is flooded by tides in brackish areas. Mangroves ecosystems have experienced a very large decrease in area especially in Madura region. This research was conducted in Taddan Village, Camplong District, Sampang. The objectives of this research were to identify mangrove vegetation, mangrove area and mangrove characteristics. The area of mangroves in the research location was 48 ha. There were 7 types of mangroves found, e.g Rhizophora apiculata, Rhizophora stylosa, Rhizophora mucronata, Sonneratia alba, Sonneratia caseolaris, Avicennia marina and Avicennia alba. The type of substrate in the mangrove research location was mainly mud. The distribution pattern of mangroves at the research location tends to spread in groups, with a low level of mangrove diversity. The uniformity index value is balanced, or in other words, there are individuals who dominate. The average sediment depth is 24.7 cm, the average salinity is 36.7 ppt, the average water pH is 5.3, the average DO is 5.9 mg / l, the average water temperature is 31, 70C, the average soil pH is 6.4. Further analysis concluded that environmental parameters in the area was unsuitable for marine tourism.

This research was carried out in September 2022 at Muara Jenggalu, Bengkulu City. The mangrove vegetation in Muara Jenggalu, Bengkulu City consists of 8 (eight) true mangrove species : Avicennia alba, Avicennia marina, Bruguiera gymnorrhiza,Lumnitzera littorea, Rhizophora apiculata, Sonneratia alba, Sonneratia caseolaris and Xylocarpus granatum. Associated mangrove species consist of 3 (three) species, namely Nypa Fruticans, Hibiscus tiliaceus L, and Pandanus tectorius.The most common types of mangroves found in the Jenggalu Estuary, Bengkulu City, are Rhizophora apiculata and Sonneratia alba. The density of mangrove species in Muara Jenggalu, Bengkulu City, is categorized as rare, with a density value of mangrove species ≤ 1,000 ind/ha. Coverage of mangrove species in Muara Jenggalu is 69.59-86.27%. The lowest type of closure is 0.18-49.68%. The type of mangrove with the highest IVI in Muara Jenggalu, namely Sonneratia alba, plays an important role in the mangrove area of Muara Jenggalu with an IVI range of ≥ 121.55-163.28. The dominance index ranged from 0.45-0.78, and the diversity index (H') ranged from 0.34-0.93.

A total of 21 species of true mangroves, namely Rhizophora apiculata, R. mucronata, Bruguiera gymnorhiza, B. sexangula, B. cylindrica, B. parviflora, Ceriopstagal, C. decandra, Avicennia alba, A. officinalis, A. marina, Xylocarpus granatum Heritiera fomes, X. moluccensis, Sonneratia alba, S. graffithii, Heritiera forms, H. littoralis, Aegialitis rotundifolia, Aegiceras corniculatum, Excoecaria agallocha and Nypa fruticans were recorded from five study sites; Kapa, Masanpa, Panadoung, Kywekayan and Kyaukphyar in Myeik area from December 2017 to July 2018. Among these, 2 species were Near Threatened (NT), 1 species was Critically Endangered (CR) and 1 species was Endangered (EN) under the IUCN Red List. Rhizophora apiculata, R. mucronata,Avicennia officinalis, Sonneratia alba, Aegiceras corniculatum, and Nypa fruticans were distributed in all 5 study sites whereas Bruguiera gymnorrhiza and Heritiera littoralis are rarely found only in one study site. Kapa was designated as an area of the most abundant species composition representing 17 species, whereas Kyaukphyar representing 12 species as the least composition. The mangrove area in Kyaukphyar is the most degraded area among the study sites, due to urban development and industrialization. The environmental parameters such as salinity and temperature of seawater, and temperature and pH of soils of each study site were presented.

The mangrove forest ecosystem in Sungai Kayu Ara Village, Sungai Apit Subdistrict, Siak Regency, Riau Province has a unique or distinctive appeal, which has the potential to be developed as a mangrove forest ecotourism destination. The research objective was to analyze the potential for developing mangrove forest ecotourism in Sungai Kayu Ara Village in realizing sustainable mangrove forest conservation. The method used in this research is the survey method, which was carried out in May-July 2020. Mangrove density data was taken using the line transect plot technique, which consists of 3 observation transects. Each transect has 3 plots, each plot measuring 10 x 10 m2. The identification results found 6 types of mangroves that grow in the mangrove forest area of Sungai Kayu Ara Village, namely Rhizophora apiculata, Avicennia alba, Bruguiera gymnorrihiza, Sonneratia alba, Nypa fruticans, and Xylocarpus granatum. The mangrove density value is 1234 ind / ha. The average value of the Tourism Suitability Index (IKW) is 76.75%. (S2 category), which is suitable for development as a mangrove forest ecotourism area. Mangrove forest ecotourism development strategies based on SWOT analysis include 1) Increasing stakeholder cooperation for mangrove forest conservation; 2) Developing facilities and infrastructure for the development of mangrove forest ecotourism; 3) Provision of information and promotion of manrove ecotourism through print and electronic media; and 4) Increased quality of skilled and skilled human resources for the development of mangrove forest ecotourism.

Abstract. Taher MM, Kamal MM, Zairion. 2012. Potential and management of mangrove ecosystem in South Jailolo Sub-district of West Halmahera, North Moluccas. Bonorowo Wetlands 2: 19-30. Mangrove ecosystem in South Jailolo District has many functions for the coastal area. This is a concern because the extent of mangrove ecosystems decreases from year to year due to the exploitation and conversion for various purposes without considering the ecological and physical functions of mangrove ecosystems. This research aims to describe the potential and existing conditions of the mangrove ecosystem and give a directive policy strategy for managing the mangrove ecosystem in this area. This study aims to determine the condition of mangrove ecosystems in the District of South Jailolo, assessing the potential ecological and economic impacts of mangrove ecosystems and how significant a reduction in mangrove area over the past 17 years, and then set the strategy of sustainable management of mangrove ecosystems This research using primary and secondary data. Primer data gathering is done by sampling, field observation, questioner, the open interview ended, and in-depth interview in the research area—secondary data gathering by unraveling various literature and related institutions. Although the reduction in mangrove forest area is still in small quantities, to maintain sustainability and ecological function, it needs management strategies. Results of analysis for management strategies found that is conservation to preserve the mangrove ecosystem area (34%), managing the mangrove ecosystem as ecotourism (32%), conservation of mangrove land as aquaculture area (21%), and make local regulations for the management of mangrove ecosystems (13%).

The distribution of mangrove area, density, and species diversity on the North Coast of Jakarta indicate the mangrove adaptation to live and grow in permanent water inundation areas. Therefore, this research aimed to analyze the distribution and mapping of the mangrove ecosystem in permanent water inundation area using the index of mangrove density, diversity, and geographical information system. The results showed that soil water salinity ranged from 5.6 to 7.0 ppt, water salinity ranged from 0.1 to 9.8 ppt, soil water pH ranged from 6.25 to 7,0, water pH ranged from 5.83 to 6.5, soil nitrate ranged from 12.2 to 22.8 mg/L, soil phosphate ranged from 1.7 to 14.8 mg/L, soil pyrite ranged from 0.12 to 0.3 mg/L, and soil texture varied from silt loam to silty clay loam. The mangrove ecosystem on the North Jakarta was dominated by a very rare density and low–moderate diversity, with a density between 440–1,250 trees/ha. The distribution of mangrove area also showed a very rare density from 0.18 ha (2000) to 166.95 ha (2020), a rare from 197.03 ha (2000) to 359,72 ha (2020), the moderate from 263.65 ha (2000) to 351.09 ha (2020), the dense from 591.78 (2000) to 273.92 ha (2020), and the very dense from 486.35 ha (2000) to 98.91 ha (2020). The mangrove ecosystem in the North Coast Jakarta was dominated by Avicennia marina, Rhizophora mucronata, Rhizophora apiculata, Rhizophora stylosa, Nypa frutican, Sonneratia alba and Sonneratia caseolaris. The conclusions of this research showed that the mangrove ecosystem inJakarta is degraded because it is dominated by rare- very rare of mangrove density Keywords: mangrove distribution, mangrove density and diversity, North Coast of Jakarta, permanent water inundation

Analysis of mangrove distribution using satellite images in Rembau River, Negeri Sembilan, Malaysia

Abstract. Pasa AE, Solano VJD, Figueroa SMS, Valenzona EO, Buhay AFV, Buot Jr IE. 2024. Floristic diversity of Naungan mangrove ecosystem in Ormoc, the largest port city in Leyte, Philippines. Biodiversitas 25: 2093-2103. Assessing the floristic diversity of the Naungan mangrove ecosystem in Ormoc, the largest port city in Leyte and a highly susceptible area to geologic and natural hazards, extreme weather events and human disturbances, is vital to determine available resources and ecosystem services for communities. This study aimed to evaluate the present state of the mangrove ecosystem in Naungan by analyzing its floristic diversity, composition, and structural characteristics. A total of 55 nested quadrats were established as observation points, measuring 10 m x 10 m and 5 m x 5 m to document the upper canopy and understorey vegetation, respectively. Mangroves with a diameter of 10 cm and above were recorded for the upper canopy while plants with diameter below 10 cm were recorded for the understorey. Results showed that the upper canopy vegetation has a total of 331 individuals of which are 10 tree species belonging to 8 families while the understorey canopy has a total of 1,310 individuals of which are 23 species belonging to 15 families. The diversity of upper canopy vegetation, as measured by the Shannon index, is notably low at 1.492. Similarly, the understorey diversity, with a value of 2.198, falls into the low category. When considering the combined diversity of both upper and lower canopies, the overall score remains low at 2.176. Avicennia marina is the most dominant upperstorey species with a relative abundance of 0.39275 followed by Sonneratia alba with 0.27492 and Avicennia officinalis with 0.16012. The understorey is also dominated by Avicennia marina with a relative abundance of 0.352672 followed by Nypa fruticans with 0.118321 and Rhizophora apiculata with 0.10229. Aegiceras floridum and Ceriops decandra are “nearly threatened” while the other species are under the “least concern” category. The area is managed by a people’s organization but threats such as fishpond establishment, road construction, and subsistence farming remain and are expected to affect mangrove diversity and ecosystem services. A mangrove ecosystem conservation framework is proposed, incorporating the importance of policy intervention and local participation in realizing sustainable mangrove ecosystems and stable provisions of the ecosystem services.

Aceh Singkil west coast of Northern Sumatra was affected by natural catastrophes both tsunami and coastal deformation. Apparently most of the inter-tidal vegetation communities suffered because of the inundation intensity and duration changed. Investigation was carried on the structure and composition of littoral and mangrove forests in Singkil coast for 52 and 49 months after the 2004 and 2005 natural catastrophes, respectively. In each vegetation type, data were collected from four sampling plots, each measuring 30 m x 30 m. The sampling plots were separated into 10 m x 10 m sub-plots for matured trees and 5 m x 5 m sub-plots for smaller trees or shrubs. All plants within the subplots were identified and counted. Pure stand of littoral forests were dominated by Casuariana equisetifolia in the mature stage and Cerbera manghas in regeneration stages as natural regeneration. In the mangrove area, most of the mangrove trees such as Bruguiera gymnorrhiza, B. parviflora, and Rhizophora apiculata dead. Sonneratia caseolaris was higher survival rate compared than mangrove trees. B. gymnorrhiza seedlings were growing well. Mangrove palm Nypa fruticans populations were recorded growing well and with a good resiliency and persistence. In fact some of coastal vegetations both in coastal dry lands and in wetland forests have a good capacity to naturally restore and grow after the environmental destruction. From ecological point of view, these plant species should be selected for rehabilitation program in the natural catastrophes both tsunami and coastal subsidence as the impact of large earthquake could be reduced.

Abstract. Hilmi E, Sari LK, Cahyo TN, Dewi R, Winanto T. 2022. The structure communities of gastropods in the permanently inundated mangrove forest on the north coast of Jakarta, Indonesia. Biodiversitas 23: 2699-2710. The permanently inundated mangrove ecosystem support gastropods communities to live and grow. The gastropods communities require a mangrove ecosystem for feeding, spawning, nursing, distributing, and breading. The distribution of gastropod communities is shown by the number, association, and clustering of gastropods and is influenced by the potential of permanent water inundation. This research used association, clustering, and correlation methods to describe the distribution of gastropod communities. The results of this research showed that the mangrove ecosystem on the north coast of Jakarta was dominated by Avicennia marina, Bruguiera gymnorrhiza, Calophyllum inophyllum, Cerbera manghas, Excoecaria agallocha, Nypa fruticans, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Sonneratia caseolaris, Terminalia catappa, and Thespesia populnea with density between 20-2800 trees/ha. However, the gastropods communities in the mangrove ecosystem were dominated by Cassidula angulifera, Cassidula aurisfelis, Cassidula plecotrematoides, Cassidula rugata, Ellobium aurisjudae, Ellobium gangeticum, Pythia plicata, Cerithidea obtusa, Cerithidea quoyii, and Melanoidessarius tuberculata with abundance between 0.36 to 6.68 ind/m2, 12 pairs positive association from 78 pairs, had uniform distribution (Moroshita index 0-0.87), and two clusters.

Background : Mangrove is a complex ecosystem that is unique and has a large enough carrying capacity for the surrounding environment. Mangrove ecosystems have ecological and economic functions. The ecological function is to protect the coastline, habitat, feeding ground, spawning ground and nursery ground for aquatic biota as well as controlling the microclimate. Meanwhile, its economic function is to produce raw materials for charcoal and medicines. Mangrove ecosystems have high biological productivity, but about 5% are consumed directly by terrestrial animals, and as much as 95% as debris from litter or leaf fall. In the Dokyar Hamlet area of Kaibobu Village, the mangrove forest ecosystem plays a very important role in maintaining the environmental balance in the area, because it is close to the villages. This area has unspoiled mangrove forests. However, there is no information regarding the types of mangroves in Dokyar Hamlet, Kaibobu Village, so it is necessary to conduct research on an identification of mangrove species found in the waters of Dokyar Hamlet, Kaibobu Village. Methods: This research was conducted in October 2020 with a sampling location taking place in Dokyar Hamlet, Kaibobu Village, Kairatu District, West Seram Regency, Maluku. The observation method used in the research and the sampling of mangroves used the line transect method, while the identification of mangroves was by observing the roots, stems, leaves, flowers and fruits. Results: Mangrove found 7 species from 6 genera: Bruguiera gimnorrhiza, Ceriops tagal, Nypa fruticans, Rhizophora apiculata, Rhizhopora mucronata, Sonneratia alba and Xylocarpus granatum Conclusion: The results of research in the mangrove ecosystem area of Dokyar Hamlet, Kaibobu Village, found 7 mangrove species belonging to 6 genera. Keywords: ecosystem, identification, mangroves

Mangrove forests are one of the most important coastal ecosystems as they support many local communities. However, over the last two decades harvesting of mangrove forests has been extensive with effects on mangrove biodiversity and ecosystem services. We investigate the effect of mangrove harvesting on tree biodiversity in South Sulawesi, Indonesia. Using two line transects each in ten mangrove forests, mangrove composition, species dominance, density, frequency, coverage, and stem diameter and diversity were recorded. Interviews detailing provisioning ecosystem services were also conducted with local forestry and fishery workers to determine the level of exploitation. Ten mangrove species were recorded (Avicennia alba, Bruguiera gymnorrhiza, Ceriops tagal, Excoecaria agallocha, Lumnitzera racemosa, Nypa fruticans, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, and Sonneratia alba) belonging to six families (Avicenniaceae, Rhizophoraceae, Euphorbiaceae, Combretaceae, Arecaceae and Sonneratiaceae). Mangrove forests are now dominated by saplings and seedlings, with few trees above 15 cm diameter at breast height. Rhizophora sp. were found to be the most important and dominant species. Rhizophora sp. was the most widely used as it was deemed the most suitable for firewood and charcoal. In addition, it is the main species planted in mangrove restoration projects, which have focused on establishing production forest rather than restoring natural species composition and structure. Despite the decrease in biodiversity, the mangroves still provide a wide range of ecosystem services to the communities in the area.