Distribution patterns and biogeography of Sargassum (Fucales, Phaeophyceae) along the coast of Vietnam

2020 ◽  
Vol 63 (5) ◽  
pp. 463-468 ◽  
Author(s):  
Tu Van Nguyen ◽  
Sung Min Boo
Keyword(s):  
Endemic Species ◽  
Distribution Patterns ◽  
Ecological Disturbance ◽  
North Central ◽  
Southern Group ◽  
The North ◽  
South West ◽  
Asian Medicine ◽  
Coast Of Vietnam ◽  
Sargassum Swartzii

AbstractSargassum species form large beds that play an important role in coastal ecosystems. The beds are abundant and Sargassum is often used as food and in Asian medicine in Vietnam. As a base for future use and conservation, we surveyed 14 species of Sargassum at eight locations during April-May of 2018 and 2019. Sargassum species from Vietnam were divisible into northern and southern groups; the northern group comprised Sargassum graminifolium, Sargassum herklotsii, and Sargassum cotoense, which occur in the North and North Central zones. The southern group comprised Sargassum bicorne, Sargassum feldmannii, Sargassum ilicifolium, Sargassum swartzii, and two endemic species, Sargassum phamhoangii and Sargassum quinhonense, which occur in the Central to South West zones. Three species, Sargassum aquifolium, Sargassum oligocystum, and Sargassum polycystum, were widespread along the long coast of Vietnam. This is the first report on distribution patterns of Sargassum species along the long coast of Vietnam. Our study provides baseline data for evaluating ecological disturbance and risks of Sargassum-associated ecosystems.

scholarly journals PHYLOGENETIC ANALYSIS AND SPECIES IDENTIFICATION OF 11 GORGONIAN CORALS (OCTOCORALLIA: ALCYONACEA) IN THE NORTH CENTRAL COAST OF VIETNAM BASED ON MSH1MTDNA AND 28S RDNA MARKERS

2021 ◽  
Vol 9 (08) ◽  
pp. 505-514
Author(s):  
Nguyen Chi Mai ◽  
◽  
NinhThi Ngoc ◽  
Nguyen Xuan Cuong ◽  
Nguyen Hoai Nam ◽  
...  
Keyword(s):  
Species Identification ◽  
Phylogenetic Analyses ◽  
28S Rdna ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Traditional Classification ◽  
Gorgonian Corals ◽  
Coast Of Vietnam

Vietnam contains diverse marine ecosystems with the high biodiversity of marine organisms, including gorgonian corals of Alcyonacea order. In order to support traditional classification of these corals, in this study mitochondrial barcoding markers msh1 and nuclear 28S rDNA were developed for analysis of 11 specimens collected in 2015 and 2016 from different islands and bays along the North Central coast of Vietnam. Phylogenetic analyses based on msh1 and 28S sequence polymorphism showed that all specimens belonged to Anthozoa class, Octocorallia sub-class and Alcyonacea order. At lower taxa levels, they were divided into 4 sub-orders, 7 families and 7 genera according to 7 distinct clades with bootstrap values from 99-100%.The identifications of 7 out of 11 specimens including Sinularia brassica (2 specimens)and Sinularialeptoclados, Dichotellagemmacea, Annella reticulata, S. conferta and S. nanolobata were in concordance between morphological and molecular methods. The other 4 specimens were only identified at genus levels of Astrogorgia sp., Melithaea sp. Scleronephthya sp. and Muricella sp. by either msh1-morphology or msh1-28S markers. These results highlight the importance of molecular markers to elucidate patterns of biodiversity and species identification of soft coral.

The Intermediate Depth Waters of the Tasman and Coral Seas. II.The 26.80σt surface

1960 ◽  
Vol 11 (2) ◽  
pp. 148 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Distribution Patterns ◽  
Intermediate Depth ◽  
The North ◽  
Winter Distribution ◽  
South West ◽  
Tasman Sea ◽  
Antarctic Convergence ◽  
Horizontal Mixing ◽  
The Antarctic ◽  
The Western Pacific

The distribution of salinity, dissolved oxygen, and phosphates on the 26.80 σt surface of the Tasman and Coral Seas is examined. The distribution patterns of these properties and the relations of salinity and phosphate and salinity and oxygen values are explained by horizontal mixing of three water types. These originated, one to the north of the Antarctic Convergence, one in the south-west Tasman, possibly in the Australian Bight, and one at the equator in the western Pacific. The major sinking regions and the circulation paths of subtropical waters in the Tasman Sea are deduced from their summer and winter distribution and from the topography of the 26.80 σt, surface.

Phytogeography of the tropical north-east African mountains

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 525-532 ◽  
Author(s):  
I. Friis
Keyword(s):  
Distribution Patterns ◽  
The South ◽  
East African ◽  
North East ◽  
The North ◽  
South West ◽  
Unpublished Studies ◽  
Mountain System ◽  
Mountain Chain ◽  
The Individual

The tropical north-east African mountains are tentatively divided into four phytochoria, the formal rank of which is not defined. The division is based on patterns of distribution and endemism in the region. The recognition of a distinct Afromontane phytochorion is now well established (Chapman White, 1970; Werger, 1978; White, 1978). However, there is still very little information on the phytogeography of the individual mountains or mountain systems. This study hopes to fill a little of the gap by analysing distribution patterns and patterns of endemism in the flora of the tropical north-east African mountains. The north-east African mountain system is the largest in tropical Africa (see e.g. map in White, 1978). At the core of this system is the large Ethiopian massif, around which are located various mountains and mountain chains. These include the Red Sea Hills in the Sudan, the mountain chain in northern Somalia, the south-west Arabian mountains, and the Imatong mountains of south-east Sudan. The latter are often referred to the East African mountain system (White, 1978) but. as I will point out later, they also have a close connection with the south-west highlands of Ethiopia. The paper presents some results of my study of the mountain flora of tropical north-east Africa, particularly the forest species. Where no source is indicated, the data are from my own unpublished studies.

scholarly journals Hydrodynamic Condition Modeling along the North-Central Coast of Vietnam

2020 ◽  
Vol 10 (3) ◽  
pp. 5648-5654
Author(s):  
D. D. Cham ◽  
N. T. Son ◽  
N. Q. Minh ◽  
N. T. Hung ◽  
N. Tien Thanh
Keyword(s):  
Sediment Transport ◽  
River Flow ◽  
Morphological Changes ◽  
Main Channel ◽  
Low Flow ◽  
Hydrodynamic Condition ◽  
Central Coast ◽  
North Central ◽  
The North ◽  
Coast Of Vietnam

An extremely dynamic morphology of the estuary is observed in the coastal regions of Vietnam under the governing processes of tides, waves, and river system flows. The primary target of this paper is to provide insight into the governing processes and morphological behavior of the NhatLe estuary, located in the north-central coast of Vietnam. Based on measured data from field surveys and satellite images combined with numerical model simulations of MIKE and Delft3D, the influences of seasonal river flow, tides, and wave dynamics on the sediment transport and morphological changes are fully examined. The study showed that freshwater flow in the flood season plays a central role in cutting off the southern sandspit, maintain and shaping the main channel. The prevailing waves in winter and summer induce longshore drift and sediment transport in the southeast to northwest direction. In the low flow season, this longshore sediment transport is dominant, causing sediment to deposit on the southern side of the ebb tidal delta and elongating the southern sandspit which narrows the estuary entrance and reorients the main channel.

Strong win by Nigeria's Buhari may prove deceptive

2019 ◽  
Keyword(s):  
The South ◽  
North Central ◽  
Content Type ◽  
The North ◽  
South West ◽  
Public Pressure ◽  
Strategic Changes ◽  
Security Crises

Significance Buhari’s victory largely replicated the scope of his 2015 win, with high margins in northern states and victories across most of the south-west and parts of the north-central ‘Middle Belt’. However, the margins in the north are lopsided enough to raise serious questions about tampering by the ruling All Progressives Congress (APC), suggesting that Buhari’s mandate could be much weaker than at first glance. Impacts Buhari’s re-election could reduce the chances of widespread post-election clashes, although some gubernatorial contests could turn violent. Despite likely renewed public pressure for Buhari to address northern security crises, fundamental strategic changes may prove elusive. New divisions may appear in the APC, with south-western politicians pushing for a presidential pick from their zone for the 2023 polls.

scholarly journals Risk management and logistical performance: A case of the fishery supply chain north central coast of Vietnam

2021 ◽  
Vol 9 (3) ◽  
pp. 739-744 ◽  
Author(s):  
Tho Nguyen Gia ◽  
My Mai Bac ◽  
Vien Le Van
Keyword(s):  
Supply Chain ◽  
Central Coast ◽  
North Central ◽  
Operational Risks ◽  
The North ◽  
Market Risks ◽  
Study Results ◽  
Supply Risks ◽  
Coast Of Vietnam ◽  
The Impact

In any given supply chain, risks can occur, and it can reduce the performance of an entire production line. To maintain a competitive advantage, manufacturers should anticipate and manage risks. This paper aims to assess the impact of risks associated with the fishery supply chain on logistics performance. The research was conducted with 297 seafood producers on the North Central Coast of Vietnam. The study results show that risk factors such as supply risks, market risks, operational risks, environmental risks, and financial risks have a direct impact on the logistical performance of firms in the fishery supply chain. The study also proposes solutions to limit risks for businesses.

scholarly journals Assessment of Soil Liquefaction Potential Based on SPT Values at Some Ground Profiles in the North Central Coast of Vietnam

2021 ◽  
pp. 2222-2238
Author(s):  
Nguyen Thi Nu ◽  
Nguyen Thanh Duong ◽  
Bui Truong Son
Keyword(s):  
Standard Penetration Test ◽  
Wide Distribution ◽  
Soil Liquefaction ◽  
Traffic Load ◽  
Engineering Practice ◽  
Central Coast ◽  
Liquefaction Potential ◽  
North Central ◽  
The North ◽  
Coast Of Vietnam

     The North Central Coast of Vietnam has a wide distribution of loose sand which is often exposed on the surface. The thickness changes from a few meters to over ten meters. This sand with the loose state can be sensitive to the dynamic loads, such as earthquakes, traffic load, or machine foundations. It can be liquefied under these loadings, which might destroy the ground and buildings. The Standard Penetration Test (SPT) is widely used in engineering practice and its values can be useful for the assessment of soil liquefaction potential. Thus, this article presents some ground profiles in some sites in the North Central Coast of Vietnam and determines the liquefaction potential of sand based on SPT and using three parameters, including the Factor of Safety against Liquefaction (FSLIQ), Liquefaction Potential Index (LPI), and Liquefaction Severity Number (LSN). The research results show that the FSLIQ, LPI, and LSN values depend on the depth of sand samples and the SPT values. In this study, the sand distributed from 2.0 to 18.0m with (N1)60cs value of less than 20 has high liquefaction potential with FSLIQ<1, LPI is often higher than 0.73, and LSN is often higher than 10. The results also show that many soil profiles have high liquefaction potential. These results should be considered for construction activities in this area.

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