• Ocean and Polar Research
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• v.35 no.4
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• pp.427-439
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• 2013

Carbon cycling and productivity within Weno Island of Micronesia enclosed by the coral reef may be likely self-maintained and insignificantly affected by the open ocean. Therefore, it is important to understand the role of the mangrove known as providing the organic matter and habitats for many organisms in this enclosed area. In order to trace the nutritional source of fauna (mostly invertebrates) in the mangrove forest of Weno island, we analyzed the fatty acid (FA) and carbon and nitrogen stable isotopes of potential nutritional sources (mangrove leaf & pneumatophore, seagrass leaf & root, surface sediment, and particulate organic matter (POM) in water) and consumers (4 gastropods and anomura). The mangrove and seagrass contained the abundance of 18:2${\omega}$6, and 18:3${\omega}$3, whereas FAs associated with phytoplankton and bacteria were accounted for a high proportion in the surface sediment and POM. FA composition of consumers was found to be similar to those of the surface sediment, mangrove, and seagrass. These were also confirmed through the mixing model of stable isotope for contribution of nutritional sources to consumers. Overall results with the feeding types of investigated mangrove fauna indicate that investigated mangrove fauna obtained their nutrition from the various sources, i.e. the mangrove for Littorina cf. scabra, the microalgae for Strombus sp., and omnivorous Pagurus sp. and Terebralia cf. palustris. However, it is obvious that the nutrition of most species living in the mangrove ecosystem is highly dependent on the mangrove, either directly or indirectly. More detail food-web structure and function of the mangrove ecosystem would be established with the analysis of additional fauna and flora.

• Journal of Forest and Environmental Science
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• v.31 no.3
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• pp.225-234
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• 2015

Mangroves are important coastal ecosystems and are located at the inter-tidal zones of tropical and sub-tropical belts. The global mangrove forests are declining dramatically because of the conversion of forests to shrimp farming, over-exploitation, pollution and freshwater diversion. The Bangladesh Forest Department initiated mangrove afforestation throughout the coastal belts of Bangladesh in 1966 to provide better protection for the coastal communities. Up to 1990, 120,000 ha of mangroves had been planted and it is one of the largest coastal afforestaton programs in the world. The objective of this study is to exploit the spatial extent of mangrove plantation and their dynamics of changes over the last two decades using multispectral Landsat imagery. The study area covers the coastal areas of Bangladesh that is extended over the eastern part of Sundarbans up to Teknaf, the southern tip of mainland Bangladesh. Mangrove plantations were interpreted visually on computer screen and interactive delineation of forest boundary was done. The mangrove plantation area has been estimated as 32,725, 47,636 and 43,166 ha for the year of 1989, 2000 and 2010, respectively. Mangrove deforestation by human activity has increased almost six times in the recent decade in comparison to the previous one. The mangrove forest loss due to coastal erosion has slightly declined in the 2000s. Mangroves have been lost primarily because of agricultural expansion. The result of this investigation will be helpful to understand the dynamics of mangrove plantation and the main drivers of changes in this coastal ecosystem.

• Proceedings of the KSRS Conference
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• v.2
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• pp.676-679
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• 2006

Mangrove crowns were delineated using active sensor LIDAR (LIght Detection And Ranging) data by a crown delineating model developed in this study. LIDAR data were acquired from airborne survey by a helicopter for the estuary of Macouria in the northeast coast of French Guiana. The canopy height image was derived from LIDAR vector data by calculating the difference between ground and non-ground data. The mangrove site in the study area was classified to three sectors by the time of mangrove settlement; Mangrove 1986, 2002 and 2003. The estimated crown of Mangrove 1986 was reliable defined for their size, number and volume because of larger crown size and bigger variation of crown height. The tree crown size of Mangrove 2002 and 2003 by the model was overestimated and the number of trees was much underestimated. The estimated crown was not for single crown but a crown group due to homogenous crown height and spatial resolution of LIDAR data. However the canopy height image derived from LIDAR data provided three-dimensional information of mangroves.

• Journal of Microbiology
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• v.44 no.5
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• pp.566-571
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• 2006

An archaeal 16S rRNA gene library was constructed from mangrove soil. Phylogenetic analysis revealed archaea in mangrove soil including the Crenarchaeota (80.4%) and Euryarchaeota (19.6%) phyla. The archaeal community in mangrove soil appears to be a mixture of organisms found in a variety of environments with the majority being of marine origin.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.183-190
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• 2019

Background: In the Philippines, the practice of planting mangroves over seagrass has been a practice done to promote coastline protection from damages done by storms. Despite the added protection to the coastline, the addition of an artificial ecosystem gradually inflicts damage to the ecosystem already established. In this study, seagrass communities that had no history of mangrove planting were compared with those that had mangrove planting. The percent substrate cover of seagrass in the sampling areas was determined, and the macroinvertebrates present in the sampling areas were also observed. The study was conducted based on reports of mangrove planting activity that disrupted seagrass functions on Santa Fe, Bantayan Island, Cebu. Transect-quadrat method sampling was done to assess the chosen sites. Results: Six species of seagrass was found on the site without mangrove planting which was barangay Ocoy (Cymodocea sp., Thalassia sp., Halodule sp., Enhalus sp., Halophila sp., and Syringodium sp.) and had a higher percent cover, while only four were found on the site with mangrove planting (barangay Marikaban). It was also found that barangay Marikaban had a lesser Shannon-Wiener and Simpson's index compared to barangay Ocoy. Jaccard's index of similarity between the two sites was low. Conclusion: With the results of the assessment, we recommend proper monitoring of future mangrove planting activities and that these activities should not disrupt another ecosystem as all ecosystems are important.

• Advances in environmental research
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• v.8 no.1
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• pp.39-54
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• 2019

This paper presents comprehensive scientific details about mangrove soil in Gulf of Kachchh, Gujarat. A total of ten sites were studied during November, 2011 to December, 2014 in order to know the physico-chemical characteristics of mangrove soil. The results indicated that the soil in GoK had silty loam texture. Other physico-chemical parameters ranged as; pH: 7.39-7.61, Bulk Density: 0.30 g/㎤-0.54 g/㎤, Particle Density: 1.26 g/㎤-1.76 g/㎤, Organic Carbon: 0.70%-1.13%, Organic Matter: 1.01%-1.74% and Moisture Content: 33.45%-56.38%. The paper would be useful to the stakeholders, coastal managers and scientific communities to know the mangrove soil conditions of Gulf of Kachchh for management and planning for conservation of mangrove ecosystem.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.465-475
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• 2021

The aim of this study was to characterize potential fungal species affecting mangrove species in Mexico. The phytopathogens were identified based on morphological and molecular characteristics using internal transcribed spacer (ITS1/ITS4) primers then sequenced and compared with the other related sequences in GenBank (NCBI). Three fungal species were identified as Colletotrichum queenslandicum (Weir and Johnst, 2012) from black mangrove (Avicennia germinans); Colletotrichum ti (Weir and Johnst, 2012) from white mangrove (Laguncularia racemosa) and buttonwood mangrove (Conocarpus erectus); Fusarium equiseti (Corda) from red mangrove (Rhizophora mangle). In addition, C. ti and F. equiseti were identified from mango Mangifera indica L. sampled close by the mangrove area. This study provides first evidence of anthracnose on four mangrove species caused by Colletotrichum and Fusarium species in the "Términos" coastal lagoon in Campeche State southern Mexico. This is the first time that C. queenslandicum and C. ti are reported in Mexico. F. equiseti has not been reported affecting M. indica and R. mangle until the present work. Little is known regarding fungal diseases affecting mangroves in Mexico. These ecosystems are protected by Mexican laws and may be threatened by these pathogenic fungus. This is the first report of the effect of Trichoderma harzianum TRICHO-SIN as an effective biological control against of Colletotrichum and Fusarium species.

• Ocean and Polar Research
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• v.28 no.1
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• pp.13-23
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• 2006

This study was conducted to investigate the community structure and distributional pattern of meiobenthos on the sediment of the mangrove forest and seagrass bed in the Chuuk lagoon. The samples were collected by an acryl corer at 14 stations. Nematodes were the most abundant meiobenthos, followed by ciliophorans and polychaetes; these taxa comprised more than 70% of the total abundance at all stations. The meiofuuna sampled in seagrass bed were more diverse than those of mangrove substrates. Total densities were higher in mangrove stations than other sites, averaging 1,671 to $2,967inds/10cm^2$. Densities in seagrass area ranged between 605 and $1,053inds/10cm^2$. Biomasses, however, were higher in seagrass bed $(975-2,167{\mu}g\;free\;dry\;weight/10cm^2)$ than in mangrove area $(1,064-1,180{\mu}g\;free\;dry\;weight/10cm^2)$. Ordination chart by MDS of major meiofaunal density in each station showed difference between mangrove area and seagrass area in terms of habitat of meiobenthos.

• Ocean and Polar Research
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• v.35 no.4
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• pp.415-425
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• 2013

In order to understand phytoplankton and bacterial distribution in tropical coral reef ecosystems in relation to the mangrove community, their biomass and activities were measured in the sea waters of the Chuuk and the Kosrae lagoons located in Micronesia. Chlorophyll a and bacterial abundance showed maximal values in the seawater near the mangrove forests, and then steeply decreased as the distance increased from the mangrove forests, indicating that environmental conditions for these microorganisms changed greatly in lagoon waters. Together with chlorophyll a, abundance of Synechococcus and phototrophic picoeukaryotes and a variety of indicator pigments for dinoflagellates, diatoms, green algae and cryptophytes also showed similar spatial distribution patterns, suggesting that phytoplankton assemblages respond to the environmental gradient by changing community compositions. In addition, primary production and bacterial production were also highest in the bay surrounded by mangrove forest and lowest outside of the lagoon. These results suggest that mangrove waters play an important role in energy production and nutrient cycling in tropical coasts, undoubtedly receiving large inputs of organic matter from shore vegetation such as mangroves. However, the steep decrease of biomass and production of phytoplankton and heterotrophic bacteria within a short distance from the bay to the level of oligotrophic waters indicates that the effect of mangrove waters does not extend far away.

• Journal of Forest and Environmental Science
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• v.26 no.2
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• pp.103-111
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• 2010

Wetlands perform various functions of vital socio-ecological significance playing fundamental role in moderating monsoon tidal floods and coastal protection and generate goods and products such as fish and forest resources. The depletion of mangroves is a cause of serious environmental and economic concern to many developing countries. Problems of sustainability of mangrove ecosystems are not only technical but also socio-economic. Functions played by mangrove wetlands are of fundamental importance for society. The present study aims to identify the challenges of the mangrove wetlands of Southeast coast of Chittagong, their uses and socio-economic influence on local people, and the value of ecosystem services, and to suggest how to conserve this ecosystem in a more equitable way.