Ecosystem Services Assessment for the Conservation of Mangroves in French Guiana Using Fuzzy Cognitive Mapping

In 2016, the French government adopted a law for biodiversity, setting an objective of protecting 55,000 hectares of mangroves. This objective is particularly important to French Guiana, which shelters almost 60% of French mangrove ecosystems, and where mangroves occupy three quarters of the coastline. The coast of French Guiana is also where issues associated with demographic and economic dynamics concentrate. There is thus a need to plan for an economic development that is compatible with the objective of protecting mangrove ecosystems. Ecosystem services (ES) assessment can support such decision-making, informing on the costs and benefits associated with alternative mangrove conservation strategies. While the many services provided by mangrove ecosystems are well documented worldwide, the extent to which these can be encountered in the specific case of French Guiana is currently only very partially known. Relying on the Fuzzy cognitive mapping (FCM) approach, we collected and compared the perception of multiple and heterogeneous groups of stakeholders, of the functioning of the mangrove social-ecological system at the scale of French Guiana. Results, allow to identify mangroves ES and threats particularly influenced by the high sedimentary dynamism of the shoreline. This generates two distinct components of the mangrove social-ecological system: mud banks where ecosystem services are spatially and temporally unstable, and associated with perceived constraints for key coastal activities, and estuarine mangroves where the ecosystem services usually described in the literature on mangroves can be found. Disservices associated with mangrove ecosystems were also identified as a key interaction. This can inform the research needs that should support sustainable development trajectories, fully accounting for the protection of French Guianese mangrove ecosystems.

Contrasting Effects of Local Environmental and Biogeographic Factors on the Composition and Structure of Bacterial Communities in Arid Monospecific Mangrove Soils

Mangrove ecosystems are increasingly being recognized for their potential to sequester atmospheric carbon, thereby mitigating the effects of anthropogenically driven greenhouse gas emissions. The bacterial community in the soils plays an important role in the breakdown and recycling of carbon and other nutrients.

Mangrove crab intestine and habitat sediment microbiomes cooperatively work on carbon and nitrogen cycling

Mangrove ecosystems, where litter and organic components are degraded and converted into detrital materials, support rich coastal fisheries resources. Sesarmid (Grapsidae) crabs, which feed on mangrove litter, play a crucial role in material flow in carbon-rich and nitrogen-limited mangrove ecosystems; however, the process of assimilation and conversion into detritus has not been well studied. In this study, we performed microbiome analyses of intestinal bacteria from three species of mangrove crab and five sediment positions in the mud lobster mounds, including the crab burrow wall, to study the interactive roles of crabs and sediment in metabolism. Metagenome analysis revealed species-dependent intestinal profiles, especially in Neosarmatium smithi, while the sediment microbiome was similar in all positions, albeit with some regional dependency. The microbiome profiles of crab intestines and sediments were significantly different in the MDS analysis based on OTU similarity; however, 579 OTUs (about 70% of reads in the crab intestinal microbiome) were identical between the intestinal and sediment bacteria. In the phenotype prediction, cellulose degradation was observed in the crab intestine. Cellulase activity was detected in both crab intestine and sediment. This could be mainly ascribed to Demequinaceae, which was predominantly found in the crab intestines and burrow walls. Nitrogen fixation was also enriched in both the crab intestines and sediments, and was supported by the nitrogenase assay. Similar to earlier reports, sulfur-related families were highly enriched in the sediment, presumably degrading organic compounds as terminal electron acceptors under anaerobic conditions. These results suggest that mangrove crabs and habitat sediment both contribute to carbon and nitrogen cycling in the mangrove ecosystem via these two key reactions.

Nutrient and physicochemical properties as potential causes of stress in mangroves of the central Red Sea

Mangrove ecosystems are some of the most productive and important sinks for sediment globally. Recently, there has been an increasing interest in possible causes of stress in mangroves, such as nutrient limitation, high salinity, solar radiation and temperature. We measured different factors casing stress and determined how they influenced oxidative stress and growth biomarkers in six study sites dominated by mangroves; Al Lith, South Jeddah, Dahban, Thuwal, Rabigh and Mastorah. Significant differences (P < 0.05) were recorded in water salinities and temperatures, nitrogen and phosphorus content in sediments, and antioxidant enzyme activities in different study sites. The highest salinity (40.75 ‰) and temperature (29.32°C) were recorded in the Rabigh mangrove stand, which corresponds to the lowest dissolved oxygen (5.21 mg/L). Total organic carbon, total nitrogen and total phosphorus in sediment across the study areas were in the order Rabigh>Thuwal>Dahban>Al Lith>South Jeddah>Mastorah. Total nitrogen in mangrove leaves at Rabigh was the highest and about 1.3 times higher than the total nitrogen in South Jeddah mangrove ecosystem, very different from the ratio of total nitrogen in the sediments at Rabigh and South Jeddah mangrove ecosystems. The average values of δ13C (-17.60‰) and δ15N (2.84‰) in the six mangrove ecosystems, and the highest δ13C (-13.62‰) and δ15N (4.39‰) at Rabigh in the sediments suggest that nutrient input differed among study sites. Higher nutrient levels at Rabigh mangrove ecosystem were attributed to restricted circulation, camel grazing and land runoff with agricultural waste during seasonal flooding events. However, N limitation and possibly salinity contributed to stress in Al Lith, South Jeddah, Dahban, Thuwal, Rabigh, and Mastorah mangrove ecosystems. Salinity (r = 0.9012) contribute more to stress at Rabigh.

Komunitas Gastropoda Mangrove di Sungai Perpat dan Bunting, Kecamatan Belinyu, Kabupaten Bangka

<strong>Mangrove gastropod community in Perpat and Bunting Rivers, Belinyu District, Bangka Regency</strong>. Perpat and Bunting in Bangka Regency have an adequate and natural mangrove ecosystems. However, studies on the structure of the gastropod community in this ecosystem is lacking. This study aimed to discover the structure of the gastropod community in the mangrove ecosystem. This study was carried out from October to November 2019 in riverine mangrove area located in Perpat and Bunting Rivers, District Belinyu, Bangka Regency. Samples were taken from 10 x 10 m plot from six observed stations. A total of 578 individuals of gastropoda were collected, comprised of seven families and 14 species. Number of species ranged from 4 to 9, while number of individuals ranged from 35 to 214. <em>Cerithidea quoyii</em> was a dominant species with 270 individuals (47%) and found in all stations. Gastropods community was in labile condition and prone to environmental change. Species composition of gastropods were similar in both rivers with nine identical species. However, epifaunal species were found separately from arboreal species

Multi-Stakeholder Approach in Natural Resources Management: The Case of Mida Creek and Gongoni-Marereni Mangrove Ecosystems in Kilifi County, Kenya

Multi-stakeholder approach has an overall improvement in conservation and management of mangrove forests resources, more so with a functional coordination framework among stakeholders. Mida creek and Gongoni-Marereni sites were compared in terms of the presence of the multi-stakeholders and the level of coordination and cooperation among stakeholders in conservation of mangrove forests. Data was gathered through a semi-structured interview questionnaire from Key Informants from the stakeholders present in the two sites. The data collected captured stakeholder presence on site, participation in mangrove conservation, and coordination and cooperation with others. There was a variation in multi-stakeholder participation in the two sites. Gongoni-Marereni site had less stakeholders compared to Mida creek which had more, with the latter having a greater participation of stakeholders. The Gongoni-Marereni site mangroves were degraded while in Mida creek had healthy mangroves.

Object-based image analysis (OBIA) for mapping mangrove using Unmanned Aerial Vehicle (UAV) on Tidung Kecil Island, Kepulauan Seribu, DKI Jakarta Province

Tidung Kecil Island is a conservation and mangrove cultivation area. Therefore, the potential of mangrove ecosystems on Tidung Kecil Island will have a direct role in coastal ecosystems. Accurate mangrove mapping is necessary for the effective planning and management of ecosystems and resources because mangroves function as protectors of ecological systems. The utilization of remote sensing technology that is near real-time can be used as an alternative in providing spatial data effectively. Mapping earth’s surface objects method is growing especially after the development of design, research, and production of flexible Unmanned Aerial Vehicle (UAV) platforms. The use of object-based classification methods is currently an alternative in classifying an object of the Earth’s surface using both satellite and aerial photo imagery data (orthophoto) that has a high accuracy value. This research aim is to map object based mangrove ecosystems using UAV technology on Tidung Kecil Island, Kepulauan Seribu, DKI Jakarta. The K-NN algorithm result was a good classification with 81.081% overall accuracy (OA) at the optimum value of the MRS segmentation scale 300;0,1;0.7 and divided into two classes which are mangrove and non-mangrove for 0.381 ha and 20.912 ha respectively.

Establishing community-wide DNA barcode references for conserving mangrove forests in China

Background Mangrove ecosystems have been the focus of global attention for their crucial role in sheltering coastal communities and retarding global climate change by sequestering ‘blue carbon’. China is relatively rich in mangrove diversity, with one-third of the ca. 70 true mangrove species and a number of mangrove associate species occurring naturally along the country’s coasts. Mangrove ecosystems, however, are widely threatened by intensifying human disturbances and rising sea levels. DNA barcoding technology may help protect mangrove ecosystems by providing rapid species identification. Results To investigate this potential, 898 plant specimens were collected from 33 major mangrove sites in China. Based on the morphologic diagnosis, the specimens were assigned to 72 species, including all 28 true mangrove species and all 12 mangrove associate species recorded in China. Three chloroplast DNA markers rbcL, trnH-psbA, matK, and one nuclear marker ITS2 were chosen to investigate the utility of using barcoding to identify these species. According to the criteria of barcoding gaps in genetic distance, sequence similarity, and phylogenetic monophyly, we propose that a single marker, ITS2, is sufficient to barcode the species of mangroves and their associates in China. Furthermore, rbcL or trnH-psbA can also be used to gather supplement confirming data. In using these barcodes, we revealed a very low level of genetic variation among geographic locations in the mangrove species, which is an alert to their vulnerability to climate and anthropogenic disturbances. Conclusion We suggest using ITS2 to barcode mangrove species and terrestrial coastal plants in South China. The DNA barcode sequences we obtained would be valuable in monitoring biodiversity and the restoration of ecosystems, which are essential for mangrove conservation.