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1.
Sci Total Environ ; 783: 146858, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088119

RESUMO

Seagrasses have the ability to contribute towards climate change mitigation, through large organic carbon (Corg) sinks within their ecosystems. Although the importance of blue carbon within these ecosystems has been addressed in some countries of Southeast Asia, the regional and national inventories with the application of nature-based solutions are lacking. In this study, we aim to estimate national coastal blue carbon stocks in the seagrass ecosystems in the countries of Southeast Asia including the Andaman and Nicobar Islands of India. This study further assesses the potential of conservation and restoration practices and highlights the seagrass meadows as nature-based solution for climate change mitigation. The average value of the total carbon storage within seagrass meadows of this region is 121.95 ± 76.11 Mg ha-1 (average ± SD) and the total Corg stock of the seagrass meadows of this region was 429.11 ± 111.88 Tg, with the highest Corg stock in the Philippines (78%). The seagrass meadows of this region have the capacity to accumulate 5.85-6.80 Tg C year-1, which accounts for $214.6-249.4 million USD. Under the current rate of decline of 2.82%, the seagrass meadows are emitting 1.65-2.08 Tg of CO2 year-1 and the economic value of these losses accounts for $21.42-24.96 million USD. The potential of the seagrass meadows to the offset current CO2 emissions varies across the region, with the highest contribution to offset is in the seagrass meadows of the Philippines (11.71%). Current national policies and commitments of nationally determined contributions do not include blue carbon ecosystems as climate mitigation measures, even though these ecosystems can contribute up to 7.03% of the countries' reduction goal of CO2 emissions by 2030. The results of this study highlight and promote the potential of the southeast Asian seagrass meadows to national and international agencies as a practical scheme for nature-based solutions for climate change mitigation.


Assuntos
Mudança Climática , Ecossistema , Sudeste Asiático , Carbono/análise , Sequestro de Carbono , Sedimentos Geológicos , Índia , Filipinas
2.
Mol Ecol ; 23(24): 6029-44, 2014 12.
Artigo em Inglês | MEDLINE | ID: mdl-25384848

RESUMO

Information on genetic diversity and differentiation of seagrass populations is essential for the conservation of coastal ecosystems. However, little is known about the seagrasses in the Indo-West Pacific Ocean, where the world's highest diversity of seagrasses occurs. The influence of sea currents on these populations is also unknown. We estimated the genetic diversity and population genetic structure and identified reproductive features in Enhalus acoroides populations from the Yaeyama Islands, Hainan Island and the Philippines. The Philippines are situated at the centre of the E. acoroides range, Yaeyama and Hainan are peripheral populations, and the Yaeyama population is at the northern limit of the species range. The powerful Kuroshio Current flows from the Philippines to Yaeyama. Genetic analyses using nine microsatellite markers indicated that reproduction of E. acoroides is mostly sexual. Clonal diversity does not decrease in northern populations, although genetic diversity does. However, the genetic diversity of the Yaeyama populations is greater than that of the Hainan populations. Significant genetic differentiation among most populations was evident; however, the Yaeyama and north-east Philippines populations were genetically similar, despite being separated by ~1100 km. An assignment test suggested that recruitment occurs from the north-east Philippines to Yaeyama. The strong current in this region is probably responsible for the extant genetic diversity and recruitment patterns.


Assuntos
Variação Genética , Genética Populacional , Hydrocharitaceae/genética , Movimentos da Água , China , DNA de Plantas/genética , Genótipo , Ilhas , Japão , Repetições de Microssatélites , Dados de Sequência Molecular , Filipinas , Análise de Sequência de DNA
3.
Mar Pollut Bull ; 88(1-2): 81-5, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25304738

RESUMO

Effects of fish culture can alter the adjacent ecosystems. This study compared seagrass species compositions in 2012 with those in 1995, when fish culture was less intensive compared to 2012 in the region. Observations were conducted at the same four sites around Santiago Island, Bolinao: (1) Silaqui Island, (2) Binaballian Loob, (3) Pislatan and (4) Santa Barbara, and by using the same methods as those of Bach et al. (1998). These sites were originally selected along a siltation gradient, ranging from Site 1, the most pristine, to Site 4, a heavily silted site. By 2012, fish culture had expanded around Sites 2, 3 and 4, where chlorophyll a (Chl a) was greater in 2012 than in 1995 by one order of magnitude. Enhalus acoroides and Cymodocea serrulata, which were recorded in 1995, were no longer present at Site 4, where both siltation and nutrient load are heavy.


Assuntos
Aquicultura , Ecossistema , Hydrocharitaceae , Animais , Clorofila/análise , Clorofila A , Ilhas , Estudos Longitudinais , Filipinas , Densidade Demográfica
4.
Mar Pollut Bull ; 83(2): 408-16, 2014 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-24746094

RESUMO

Seagrass systems of the Western Pacific region are biodiverse habitats, providing vital services to ecosystems and humans over a vast geographic range. SeagrassNet is a worldwide monitoring program that collects data on seagrass habitats, including the ten locations across the Western Pacific reported here where change at various scales was rapidly detected. Three sites remote from human influence were stable. Seagrasses declined largely due to increased nutrient loading (4 sites) and increased sedimentation (3 sites), the two most common stressors of seagrass worldwide. Two sites experienced near-total loss from of excess sedimentation, followed by partial recovery once sedimentation was reduced. Species shifts were observed at every site with recovering sites colonized by pioneer species. Regulation of watersheds is essential if marine protected areas are to preserve seagrass meadows. Seagrasses in the Western Pacific experience stress due to human impacts despite the vastness of the ocean area and low development pressures.


Assuntos
Alismatales/fisiologia , Ecossistema , Biodiversidade , Mudança Climática
5.
PLoS One ; 8(8): e65735, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23976940

RESUMO

Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010-2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Peixes/fisiologia , Animais , Antozoários/fisiologia , Recifes de Corais , Filipinas , Dinâmica Populacional , Áreas Alagadas
6.
Mar Genomics ; 11: 27-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23751211

RESUMO

Ten novel polymorphic nuclear microsatellite simple sequence repeat (SSR) markers were isolated from an Indo-Pacific horned starfish, Protoreaster nodosus. The isolated SSR markers provided polymorphisms of 2-9 alleles per locus in three populations obtained from Indonesia and the Philippines. The expected and observed heterozygosities ranged from 0.049 to 0.691 and from 0.050 to 0.800, respectively. Pairwise FST values among three populations ranged from 0.018 to 0.050 (global FST=0.031). All P. nodosus individuals collected from three populations exhibited different genotypes for the ten identified SSR markers, indicating that P. nodosus reproduces sexually. Then the developed SSR markers will be useful for studying the population and conservation genetics of P. nodosus.


Assuntos
Repetições de Microssatélites , Estrelas-do-Mar/genética , Animais , Genética Populacional , Heterozigoto , Indonésia , Filipinas , Polimorfismo Genético , Análise de Sequência de DNA
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