Carbon content in different seagrass species in Andaman Coast of Thailand

Seagrass meadows have one of the highest carbon sequestration and storage capacities than any other ecosystems. Carbon that is stored in the ecosystem is accumulated in the deposited sediment as well as in the living, above and below ground biomass, with a different rate of carbon sequestration and storage between the species. The objective of this research was to investigate carbon storage in the living plants and in the sediment among species of different size in tropical waters. The samples were collected from Phuket province, Thailand, in the high density monospecific patches of different size species (Enhalus acoroides as a big, Thalassia hemprhicii as a medium and Halophila ovalis as a small size species). Total carbon and carbon stored in above and below ground, was significantly different between the species (p<0.05), with the highest values in below ground parts of E. acoroides and T. hemprichii 238.10±85.07 and 134±21.55 g Dw m-2, respectively. Average organic carbon in the sediment was significantly different (p<0.05) as well, with E. acoroides having highest organic carbon content in the deeper layers of the sediment 1.14±0.25 % Corg, while the other two species had higher organic carbon in the top and medium layers of sediment. The results of this preliminary research propose that big size species have higher carbon content than smaller species, which reflects in higher sequestration rates of carbon from the ocean, thus reducing the ocean carbon budget. Moreover, it provides necessary information on size of the species which is the key for the future carbon storage studies in the region

Seagrass in Southeast Asia: a review of status and knowledge gaps, and a road map for conservation

Southeast Asia has the highest diversity of seagrass species and habitat types, but basic information on seagrass habitats is still lacking. This review examines the known distribution, extent, species diversity, and research and knowledge gaps of seagrasses in Southeast Asia by biogeographic region of the Marine Ecoregions of the World (MEOW). The extent of seagrass meadows in Southeast Asia is ~36,762.6 km2 but this is likely an underestimate as some ecoregions were not well-represented and updated information was lacking. There is a paucity of information from the Western Coral Triangle Province, with no areal extent data available for the Indonesian regions of Kalimantan, Central and Southeast Sulawesi, the Maluku Islands, and West Papua. Regional research output has increased in the last two decades, with a trend towards more experimental, rather than descriptive research. However, there are knowledge gaps in socio-cultural-economic themed research, despite growing awareness of the importance of seagrass-human relationships in this region. Obstacles to advancing seagrass research, knowledge and conservation are rooted in either lack of expertise and training or the failure of effective management and policies. We propose a roadmap for seagrass conservation, with suggested solutions, including 1) encouraging collaboration between research institutions and scientists in the region to build capacity and share knowledge; 2) engaging with policymakers and governments to encourage science-based policies; 3) engaging with communities to raise awareness and foster stewardship of seagrass in the region

Coastal and estuarine blue carbon stocks in the greater Southeast Asia region: Seagrasses and mangroves per nation and sum of total

Climate Change solutions include CO2 extraction from atmosphere and water with burial by living habitats in sediment/soil. Nowhere on the planet are blue carbon plants which carry out massive carbon extraction and permanent burial more intensely concentrated than in SE Asia. For the first time we make a national and total inventory of data to date for “blue carbon” buried from mangroves and seagrass and delineate the constraints. For an area across Southeast Asia of approximately 12,000,000 km2, supporting mangrove forests (5,116,032 ha) and seagrass meadows (6,744,529 ha), we analyzed the region's current blue carbon stocks. This estimate was achieved by integrating the sum of estuarine in situ carbon stock measurements with the extent of mangroves and seagrass across each nation, then summed for the region. We found that mangroves ecosystems regionally supported the greater amount of organic carbon (3095.19Tg Corg in 1st meter) over that of seagrass (1683.97 Tg Corg in 1st meter), with corresponding stock densities ranging from 15 to 2205 Mg ha−1 and 31.3 to 2450 Mg ha−1 respectively, a likely underestimate for entire carbon including sediment depths. The largest carbon stocks are found within Indonesia, followed by the Philippines, Papua New Guinea, Myanmar, Malaysia, Thailand, Tropical China, Viet-Nam, and Cambodia. Compared to the blue carbon hotspot of tropical/subtropical Gulf of Mexico's total carbon stock (480.48 Tg Corg), Southeast Asia's greater mangrove–seagrass stock density appears a more intense Blue Carbon hotspot (4778.66 Tg Corg). All regional Southeast Asian nation states should assist in superior preservation and habitat restoration plus similar measures in the USA & Mexico for the Gulf of Mexico, as apparently these form two of the largest tropical carbon sinks within coastal waters. We hypothesize it is SE Asia's regionally unique oceanic–geologic conditions, placed squarely within the tropics, which are largely responsible for this blue carbon hotspot, that is, consistently high ambient light levels and year-long warm temperatures, together with consistently strong inflow of dissolved carbon dioxide and upwelling of nutrients across the shallow geological plates

Spatial and temporal variations in percentage cover of two common seagrasses at Sirinart National Park, Phuket; and a first step for marine base

Percentage cover and distribution of two common seagrasses, Thalassia hemprichii (Ehrenb.) Aschers. and Cymodocea rotundata Ehrenb. Et Hempr. Ex Aschers., were studied in the dry and wet seasons. The study was carried out at three levels on sheltered, moderately exposed and very exposed sites on the coastline of Sirinart National Park, Thailand. One hundred and twenty samplings were investigated and recorded. Analysis of variance (ANOVA) revealed that there were significant differences in the percentage cover of C. rotundata among different degrees of wave exposure (P<0.01); and T. hemprichii was significantly influenced by interactions between seasons, shore levels and degrees of wave exposure (P<0.05). High sediment disturbance on the very exposed site was likely to influence the percentage cover and distribution of both seagrasses. This study provided baseline data for further work on ecological study and long term monitoring; and a first step to building up a ‘marine base’

Population ecology of a turf-forming red alga, Osmundea pinnatifida from the Isle of Man, British Isles

Available from British Library Document Supply Centre- DSC:DXN057729 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Preliminary report on the diversity and community structure of macroalgae before and after the 2004 Tsunami at Talibong Island, Trang Province, Thailand

The diversity and community of macroalgae were investigated at 3 sites at Talibong Island, Trang Province, Thailand, from April 2004 to May 2005. Preliminary studies revealed a high diversity of macroalgae on the west coast of the island. Therefore, it was decided that these were good sites to set up fifteen of 0.5m×0.5m permanent plots to monitor macroalgae community changes. Physical factors such as salinity, seawater temperature, NO3-, NO2- and Po4^<2-> were also measured. Eighteen species of macroalgae were found. Sargassum stolonifolium and Laurencia composita were the most abundant species, covering 90% and 39%, respectively, on the rocky substrate. Padina sanctae-crucis and Caulerpa taxifolia were the most dominant species on the sandy substrate. Thirteen species varied among the sites and seasons. Eleven species were strongly influenced by the 26 December, 2004 tsunami. L. composita and Padina sanctae-crucis, for example, were washed up to the shores by the strong tsunami wave, and clearly resulted in a decrease in percentage cover. In addition, many permanent plots were covered by sediment causing anoxic conditions. Multivariate analysis revealed that most macroalgae and sites were randomly spread out on the axis before the tsunami; but they were grouped after the tsunami hit these sites. We have not found any seasonal pattern or recovery of macroalgae after 5 months after the tsunami

Ecosystem Services and Vulnerability Assessments of Seagrass Ecosystems: Basic Tools for Prioritizing Conservation Management Actions Using an Example from Thailand

Seagrass habitats are among the most valuable coastal ecosystems. They provide a wide array of ecosystem services (ES) that support the livelihoods of many people. However, seagrass habitats worldwide are at risk of being lost due to the alteration of coastal areas by many causes. Seagrass meadows around Thailand were assessed to evaluate their ecosystem services and vulnerability (VU) status. The ES and VU analyses could be used as basic tools to assess the status of individual seagrass meadows and to prioritize the action needed among several meadows. From 82 seagrass sites, the ES of seagrass habitats tended to be varied based on the areas of the seagrass beds. The vulnerability of the seagrass habitats was mainly influenced by the threat of boating accidents and the incidence of sedimentation. The final combined analysis suggested that a seagrass site at Ban Don (BD), in Surat Thani Province, should be the priority for intervention due to the importance of the ES provided at the site and the existence of a degree of threat from poor land-use management. This work allows us to understand more about the targeted management of seagrass ecosystems, which is very important for conservation and restoration because of its significant potential carbon offset

Ecosystem Services and Vulnerability Assessments of Seagrass Ecosystems: Basic Tools for Prioritizing Conservation Management Actions Using an Example from Thailand

Seagrass habitats are among the most valuable coastal ecosystems. They provide a wide array of ecosystem services (ES) that support the livelihoods of many people. However, seagrass habitats worldwide are at risk of being lost due to the alteration of coastal areas by many causes. Seagrass meadows around Thailand were assessed to evaluate their ecosystem services and vulnerability (VU) status. The ES and VU analyses could be used as basic tools to assess the status of individual seagrass meadows and to prioritize the action needed among several meadows. From 82 seagrass sites, the ES of seagrass habitats tended to be varied based on the areas of the seagrass beds. The vulnerability of the seagrass habitats was mainly influenced by the threat of boating accidents and the incidence of sedimentation. The final combined analysis suggested that a seagrass site at Ban Don (BD), in Surat Thani Province, should be the priority for intervention due to the importance of the ES provided at the site and the existence of a degree of threat from poor land-use management. This work allows us to understand more about the targeted management of seagrass ecosystems, which is very important for conservation and restoration because of its significant potential carbon offset

Wave exposure changes reproductive output and timing on Padina boryana Thivy (Dictyotales, Phaeophyceae)

Different environments can affect the reproduction on marine organisms. Along the coastline, wave action is seemed to be the strongest stress factor that influences seaweed populations. Seaweed can grow under two different conditions of wave action. The life phases, reproduction and quantity of reproductive cells were recorded for each individual in Padina boryana. Both populations had the highest percentage of reproduction in May and dominance of sporophytes. The number of spore and time of production were different at the two sites. Increasing temperature, day length and emersion time enhanced desiccation and high temperature influencing the spore production and maturation of life phases at both locations. More wave exposure decreased the number of reductive cell and changed the pattern of production time in difference scenarios. Energy allocations can play an important role for explaining the cycle of reproduction time in a year on different populations under different wave exposure