Con Dao Island Research Articles

Assessment of groundwater vulnerability and risk to pollution in Con Dao island, Ba Ria - Vung Tau, Vietnam

Abstract The assessment of groundwater vulnerability has been widely used to manage and prevent groundwater from contamination risk. This study applied the model of GIS-based GALDIT was for groundwater vulnerability and risk assessment in a coastal district of Con Dao island, Ba Ria-Vung Tau, Vietnam. The Groundwater Risk Assessment Model (GRAM) was used to assess the risk of groundwater pollution in the study region. The GALDIT model used six hydrogeological components to generate a GALDIT Index map, which illustrates how vulnerable the local groundwater is to contamination. The platform of GIS-based GRAM was exploited to construct risk maps related to salinity intrusion, hazard release, and hazard consequences. According to the findings, more than 80% of the groundwater in Con Dao district is vulnerable to saltwater intrusion, with the greatest concentration in the district’s central section. Only 18.12% of the district, in the Co Ong region to the northeast of the Con Dao district, has low or very low susceptibility. However, after accounting for contamination barriers and the capacity to identify and detect risks, it was shown that most areas, or around 87% of the study area, had transitioned to a low-risk level of groundwater pollution. The groundwater vulnerability and risk maps created serve as baseline information for decision-makers in governance and planning to effectively monitor and protect groundwater resources from pollution.

Phylogenetic diversity patterns of woody species across different tree sizes and spatial scales in a tropical forest community on Con Dao Islands

Understanding the maintenance of diversity and the assembly of communities is a primary concern in community ecology. This study explored the phylogenetic structure of an evergreen broadleaved tree community in Con Dao National Park, Vietnam. The survey, conducted in December 2023, encompassed all tree individuals with a diameter at breast height (DBH) ≥ 2.5 cm within a 4-ha study plot. These individuals were identified by species name, and their DBH was measured. Subsequently, a community phylogenetic tree was constructed using the Phylomatic online platform. The 4-ha study plot was subdivided into there different subplots based on three spatial scales (25 m × 25 m, 50 m × 50 m, and 100 m × 100 m) and all trees were classified into three different DBH classes (2.5 cm ≤ DBH < 10 cm representing small trees; 10 cm ≤ DBH < 20 cm as medium trees; and DBH ≥ 20 cm as large trees). The net relatedness index (NRI) and net nearest taxon index (NTI) were utilized to evaluate the phylogenetic structure and infer ecological processes. Our findings revealed a consistent decrease in both NRI and NTI with increasing spatial scales and tree sizes. These results suggest an overdispersed phylogenetic structure within the community across different spatial scales and tree sizes. Additionally, negative density dependence was found to have a pronounced effect on the phylogenetic structure, with a more significant impact on tree individuals from small and medium DBH classes than large ones. This study underscores the significance of phylogenetic density dependence as a primary mechanism governing species diversity and shaping the community structure of evergreen broadleaved forests in Vietnam.

Genetic diversity, variation, and structure of two populations of bigfin reef squid (Sepioteuthis lessoniana d’Orbigny) in Con Dao and Phu Quoc islands, Vietnam

BackgroundBigfin squid is one of the economically important seafood resources in Vietnam’s fisheries and the waters around Con Dao and Phu Quoc islands are two major fishing grounds where this species has been actively exploited. The start codon targeted polymorphism (SCoT) and CAAT box–derived polymorphism (CBDP) techniques were used to generate DNA fingerprinting data to analyze the genetic diversity, variation, and structure of the two populations in the waters surrounding Phu Quoc and Con Dao islands together with mitochondrial cytochrome C oxidase subunit I (COI) gene sequence data. ResultsCon Dao population possessed a higher diversity [expected heterozygosity (He) = 0.2254, Shannon index (I) = 0.3459, percentage of polymorphic bands (PPB) = 80.14%, nucleotide diversity (π) = 0.0336, haplotype diversity (h) = 0.910 with 16 haplotypes] than Phu Quoc population (He = 0.1854, I = 0.2873, PPB = 70.38%, π = 0.0246, h = 0.838 with 14 haplotypes). The genetic diversity at species level in the investigated region was at level of He = 0.2169, I = 0.3399, PPB = 86.41, π = 0.0289, and h = 0.892 with 24 haplotypes. Based on DNA fingerprinting data, the pairwise genetic similarity coefficients among individuals of the Con Dao population were lower (average of 0.7977) than the Phu Quoc population (average of 0.8316). Based on mitochondrial COI data, the pairwise genetic distances among individuals of the Con Dao population were higher (average of 0.0361) than the Phu Quoc population (average of 0.0263). Gene differentiation (GST) between two investigated populations was 0.0316 and 0.0310 leading to the genetic distance was 0.0573 and 0.0213 and the gene flow between them was Nm = 8.2209 and 11.4700 migrants per generation among populations based on DNA fingerprinting and based on COI gene sequence data, respectively. Genetic variation within individuals of both populations (WP) played the key role in total genetic variation at species level in surveyed region. ConclusionsFor the bigfin reef squid species in the surveyed region, the Con Dao population had the higher genetic diversity than the Phu Quoc population, between them existed a low to moderate genetic differentiation and a genetic exchange via gene flow. The DNA fingerprinting data better revealed the genetic differentiation between the two surveyed populations while the mitochondrial COI gene sequence data could show the phylogenetic relationship among the surveyed individuals and the other from the sea regions in Southeast Asia. Based on the results obtained, fisheries management strategies are suggested toward the conservation and sustainable exploitation of this species.

Between a Rock and a Hard Place: Controversies over Contested Intangible Heritage in Vietnam Seen from the Case Study of Lady Phi Yen

Le Thi Ram, or Phi Yen the Imperial Concubine as she is more commonly known, is a divisive figure in the folklore of Vietnam. The inhabitants of Con Dao Island have held Phi Yen in high esteem for many years because of her noble deeds in the nineteenth century. A memorial service was organized in her honour by the Con Dao community and was added to the register of Vietnam’s intangible cultural treasures in early 2022. However, this prompted debate about the veracity of the memorial service and the character being honoured. This study uses three theoretical frameworks to analyse the debates over whether to remove the commemoration of Lady Phi Yen’s death: contested heritage, heritagization and historical revisionism. The debate centres on two opposing camps: those supporting keeping the commemoration and those who do not. This research adds to our understanding of the debates surrounding Vietnam’s efforts to protect and promote its intangible cultural heritage and suggests directions for the future.

A multi-approach framework for developing feasible, viable, and sustainable hybrid energy systems in remote areas: The case of Con Dao island in Vietnam

In remote communities, hybrid energy systems are increasingly used to improve the reliability and renewability of power supply. The techno-economic analysis is often used to develop these promising energy systems, ignoring some performance indicators and environmental factors. This study proposes a multi-approach framework for developing operationally feasible, economically viable, and environmentally sustainable hybrid energy systems in remote areas. A case study is conducted on Con Dao Island in Vietnam to supply its electricity demand using six on-grid and off-grid hybrid energy systems. After finding the best techno-economic configurations of the six developed systems, they are subjected to multi-approach analysis and exhaustive comparison using a set of performance, economic, and environmental indicators. An off-grid hybrid energy system comprising photovoltaics, wind turbines, lead-acid batteries, and diesel generators has the lowest net present cost (109.7 million USD) to supply the predicted island's electricity consumption (with a total on-site electricity generation of 184.1 GWh/yr). However, this off-grid system indicates the highest excess energy fraction (55%), while the on-grid systems with the ability to export excess energy to the grid have no excess energy fraction. In terms of eco-friendliness, an on-grid hybrid energy system consisting of a high level of photovoltaics and wind turbines shows the best results, with a negative total environmental impact and CO2-eq emissions. This on-grid system shows the best cost of energy (0.1 USD/kWh) with approximately 450% less total environmental impact than the best off-grid system investigated, offsetting about 48.2 kilotonnes of CO2-eq/yr by exporting net emission-free electricity. Overall, the proposed framework can assist decision-makers in finding feasible, viable, and sustainable hybrid energy systems.

Wave Regime of Vietnamese Waters on the Basis of Numerical Modeling and Field Measurements

This paper presents results of research of the wave regime in Vietnamese waters (South China Sea) based on the data of numerical modeling data using the WAM model (WAVE Modeling). The model domain covers the basin of the South China Sea (SCS). The bathymetry of the SCS used in the model is based on the ETOPO5 digital database. Wind parameters are based on the six-hour NCEP/NCAR reanalysis data with a resolution of ΔX = ΔY = 0.25° over the period 1979–2021. The field wave data measurements were collected by the Institute of Oceanography of Vietnam Academy of Science and Technology in the southern central Vietnamese waters in 2013. The statistical data of computed wave characteristics for the period of 43 years (1979–2021) illustrate that the main wave direction in Vietnamese waters was NE during the Northeastern (NE) monsoon, and in the opposite direction during the Southwestern (SW) monsoon. The NE monsoon wave was more dominant than that of the SW monsoon wave. Recurrence frequency (%) of significant wave height Hs >1.0 m (Hs – significant wave height is an average of 1/3 the largest of serial waves relative to average seawater level) greater than 50%
 covered the northeastern, central region of the SCS, and central Vietnamese coast. The wave recurrence frequency in the Gulf of Tonkin and Gulf of Thailand was <40% and <30%, respectively. The central Vietnamese coast from Ly Son Island to Phu Quy Island was the strongest affected by wave action. The recurrence frequency of the maximum significant wave height Hs >3.5 m was greater than 1.5%. The Gulf of Tonkin (Bach Long Vi Island) and the Gulf of Thailand (Tho Chu Island) were less affected by
 wave action than the central Vietnamese coast: the recurrence frequency of the maximum wave height (Hs>3.5 m) was less than 0.1%. Phu Quy and Con Dao Islands were more influenced by wave action during both seasons than the central coast of Vietnam.

Coral Oasis on Con Dao Islands: A Potential Refuge of Healthy Corals in the Offshore Waters of Vietnam?

Coral reefs of Vietnam are highly threatened by a combination of anthropogenic impacts and natural disturbances. As a result, preservation of the remaining reefs is a major governmental concern. Con Dao Islands, located in the coastal area of southern Vietnam in the South China Sea, still possess diverse and healthy coral communities. Coral surveys conducted in 2017–2020 on six sites within the marine protected area of Con Dao National Park revealed extensive coral cover (62.8–95.5%) and diversity (168 stony coral species). Coral communities were mostly dominated by Acroporidae followed by Poritidae and Fungiidae. Temporal dynamics over a 3-year period exhibited no significant decrease in the cover of dominant coral taxa, despite the severe thermal anomaly in 2019 and subsequent moderate coral bleaching, suggesting that the local corals may be successfully acclimating to the current level of thermal stress, although further study of coral adaptation in this region is warranted. High diversity and coral cover, together with the potential of resistance and resilience to repeated thermal stress in coral communities of the Con Dao Archipelago, highlights the need for authorities to pay special attention to this area and to expand conservational efforts to preserve this unique natural site.

Informations of 4 species with Vietnamese name “cay Nua” belonging to Araceae and Taccaceae in Con Dao

Four plant species in Con Dao shared together a Vietnamese name as “cay Nua”. They have habits, tubers and leaves quite similar each other. However, they belong to 2 families, which have caused a lot of confusions in exploitation, cultivation and use in the life. Among of them, 2 species belong to the genus Tacca (Taccaceae) as T. leontopetaloides and T. palmate, 2 remained species belong to the genus Amorphophallus as A. macrophyllus and A. coudercii. The species T. leontopetaloides is cultivated for tubers making starch and T. palmate is collected in the wild for medicine. While the tubers of A. macrophyllus and A. coudercii are not as edible tubers. For avoiding confusion in exploitation and using, the article described 4 above species and supported new morphological characters and new distribution of 2 Amorphophallus in Con Dao island.

Accuracy assessment of land use land cover LULC 2020 (ESRI) data in Con Dao island, Ba Ria – Vung Tau province, Vietnam

Managing land use in an efficient way results in food security and economic development. Recently, the Environmental Systems Research Institute (ESRI) announced a new product, LULC 2020 (ESRI), that has been produced by the classification with Artificial Intelligence (AI) technique of satellite data at 10-meter resolution. This data has global coverage and is freely available on the internet, but the questions are how good the data is and how to apply it to local practice and land use system. This study aims to answer those questions by emphasizing the accuracy assessment of the LULC 2020 (ESRI) data. The systematic samples of 281 test sites and the Geographic Information Systems (GIS) analysis have been conducted by using the Confusion matrix method in comparison with the visualization of high-resolution data from Google Earth images and field survey data. Topographic information data such as Digital Elevation Model (DEM) and slope data have been integrated for achieving better data accuracy, with overall accuracy increasing from 79.72% (Overall Kappa Statistic 0.421) to 84.34% (Overall Kappa Statistic 0.589). The improved land use types are hilly non-forest, other agricultural, and flat unused types that are typical for the local land use classification system. The study provides a new data processing method to apply LULC 2020 (ESRI) for land use mapping in Con Dao island, Ba Ria - Vung Tau province in the East Sea of Vietnam.

U-shaped deep-learning models for island ecosystem type classification, a case study in Con Dao Island of Vietnam

The monitoring of ecosystem dynamics utilises time and resources from scientists and land-use managers, especially in wetland ecosystems in islands that have been affected significantly by both the current state of oceans and human-made activities. Deep-learning models for natural and anthropogenic ecosystem type classification, based on remote sensing data, have become a tool to potentially replace manual image interpretation. This study proposes a U-Net model to develop a deep learning model for classifying 10 island ecosystems with cloud- and shadow-based data using Sentinel-2, ALOS and NOAA remote sensing data. We tested and compared different optimiser methods with two benchmark methods, including support vector machines and random forests. In total, 48 U-Net models were trained and compared. The U-Net model with the Adadelta optimiser and 64 filters showed the best result, because it could classify all island ecosystems with 93 percent accuracy and a loss function value of 0.17. The model was used to classify and successfully manage ecosystems on a particular island in Vietnam. Compared to island ecosystems, it is not easy to detect coral reefs due to seasonal ocean currents. However, the trained deep-learning models proved to have high performances compared to the two traditional methods. The best U-Net model, which needs about two minutes to create a new classification, could become a suitable tool for island research and management in the future.

Isolation Microgrid Design for Remote Areas with the Integration of Renewable Energy: A Case Study of Con Dao Island in Vietnam

In remote areas, extending a power line to the primary electricity grid can be very expensive and power losses are high, making connections to the grid almost impossible. A well-designed microgrid that integrates renewable energy resources can help remote areas reduce investment costs and power losses while providing a reliable power source. Therefore, investigating the design of an independent and economically practical microgrid system for these areas is necessary and plays an important role. This paper introduces a design procedure to design an isolated microgrid using HOMER software (HOMERPro 3.14.5) for remote areas. In Vietnam, due to the obstruction of the mountainous terrain or the isolated island location, many remote areas or islands need electrification. A simple case study of a hybrid system with a 60 kW peak load demand on Con Dao island in Vietnam is used to illustrate the proposed design method. Specifically, a hybrid system that includes a PV system, batteries, and a diesel generator is designed. To provide the full information of the designed hybrid system designed, each solution is analyzed and evaluated in detail according to the sensitivity parameters.

Analysis of composition and abundance of viral communities associated with coral \(\textit{Acropora formosa}\)

Coral reefs harbor the extraordinary biodiversity and not only provide livelihoods for coastal communities but also play a crucial role in economic development generally. Unfortunately, they are in decline in Vietnam and around the world because mass coral bleaching events have become more common worldwide. However, little is discovered, about viruses that infect corals and their symbionts. Herein, we present metagenomic analyses of the viral communities in coral mucus associated with healthy and bleached coral Acropora formosa which was collected at Con Dao Island, Vietnam. Interestingly, the number of viral species in bleached specimens are higher than those in healthy status. Viruses similar to those that infect humans and some marine animals also appeared in the coral viral assemblage. The results indicated that the proportion of shared viruses were quite small, and represented extremely abundance. Among the phage identified, vibriophage and cyanophage were only presented in healthy and bleached coral, respectively. Therefore, coral-associated viruses could prospectively infect all constituents of the holobiont - coral, microalgal and microbial. Thus, we expect viruses to be illustrated prominently in the preservation and breakdown of coral health.

Enhancing Water Supply Resilience in a Tropical Island via a Socio-Hydrological Approach: A Case Study in Con Dao Island, Vietnam

Socio-hydrological approaches are gaining momentum due to the importance of understanding the dynamics and co-evolution of water and human systems. Various socio-hydrological approaches have been developed to improve the adaptive capacity of local people to deal with water-related issues. In this study, a social-hydrological approach was developed to enhance the water supply resilience in Con Dao Island, Vietnam. We used a water-balance model, involving the Water Evaluation and Planning (WEAP) tool, to conduct a scenario-based evaluation of water demands. In doing so, we assessed the impacts of socio-economic development, such as population growth and climate change, on increasing water demand. The modelling results showed that the existing reservoirs—the main sources to recharge the groundwater (accounting for 56.92% in 2018 and 65.59% in 2030)—play a critical role in enhancing water supply resilience in the island, particularly during the dry season. In addition, future water shortages can be solved by investment in water supply infrastructures in combination with the use of alternative water sources, such as rainwater and desalinated seawater. The findings further indicate that while the local actors have a high awareness of the role of natural resources, they seem to neglect climate change. To meet the future water demands, we argue that upgrading and constructing new reservoirs, mobilizing resources for freshwater alternatives and investing in water supply facilities are among the most suitable roadmaps for the island. In addition, strengthening adaptive capacity, raising awareness and building professional capacity for both local people and officials are strongly recommended. The research concludes with a roadmap that envisages the integration of social capacity to address the complex interaction and co-evolution of the human–water system to foster water-supply resilience in the study area.

Tourism imaginaries and the selective perception of visitors: Postcolonial heritage in Con Dao Islands, Vietnam

Identifying the reasons why people visit places associated with death and suffering remains a key stake of dark tourism research. Such research, however, remains largely framed by Anglo-American perspectives and assumes visitors largely hail from the West. Less is known about the motivations of dark tourists from developing countries. This paper contributes to the debate by examining the case of tourism in Con Dao Archipelago, Vietnam. Once labeled as a ‘Hell on Earth’, the island is a famous site of both postcolonial and natural heritage, displaying former colonial prisons, prisoners’ cemeteries and memorials. Over the past five years, pilgrimage tours to the tomb of Co Sau, a national hero, in Hang Duong cemetery have increasingly attracted visitors from the Vietnamese mainland. Focusing on both the supply and demand sides of dark tourism, the research uses the theoretical lens of tourism imaginaries and visitors’ selective perception to investigate what attracted people to these tours. Document analysis, ethnographic observation and in-depth interviews with key informants show that a complicated set of factors (tourism commodification, geographic location, culture and beliefs) intersect to influence the emergence and transformation of penal sites’ imaginaries in Con Dao Islands. Despite being presented with three different imaginaries of Con Dao, visitors from Vietnam are engaged in a form of ‘spiritual tourism’ focused on the sacred element of the martyrs’ deaths and suffering, making this their main reason for visiting the island. The popularity of spiritual tours in Con Dao thus underlines the importance of looking at the islands’ heritages beyond Western conceptions of dark and resort tourism.

Bleaching of coral in Nha Trang, Ninh Thuan, Con Dao and Phu Quoc islands in June–July 2019

The studies on coral bleaching were conducted at 21 sites of 4 reef areas in Southern Vietnam, using point transect technique in June–July 2019. Cover of hard corals in the selected sites was quite high with the average values of 65.6 ± 18% % in Con Dao islands, 58.7 ± 26.2% in Ninh Thuan coastal waters, 55.9 ± 17.8% in Phu Quoc island but lower in Nha Trang bay (22.8 ± 15.9%). Soft corals were not abundant with the highest cover in Nha Trang bay (4.73 ± 5.5%) and the lowest in Ninh Thuan (0.16 ± 0.3%). Hard corals were most impacted in Nha Trang bay with 39.5 ± 8.1% bleached, followed by Ninh Thuan reefs (32.9 ± 13.3%), Con Dao Islands (25.0 ± 11.1%) and least affected in Phu Quoc island (7.3 ± 9.05%). For soft corals, ratios of bleached corals were 79.4%, 65.8% and 23.8% in Con Dao islands, Nha Trang bay and Ninh Thuan reefs respectively. No bleached soft coral was recorded in Phu Quoc. At the genus level, Acropora corals were severely affected in Nha Trang bay, Ninh Thuan reefs and Phu Quoc island but not impacted in Con Dao islands. The Porites, Montipora, Millepora genera were quite vulnerable in all sites but no bleaching was observed for Galaxea and Diploastrea genera.

Morphology, abundance and the invasiveness of coral-killing sponge <i>Chalinula nematifera</i> (Porifera: Demosponigiae) from Con Dao National Park, Vietnam

This is the first study on morphology, abundance and invasion of coral-killing sponge Chalinula nematifera (De Laubenfels, 1954) from offshore waters in Con Dao islands, Vietnam. The results of the study show that the morphology is similar to that in the Western Pacific, but differs in skeletal structure compared to the description in the Eastern Pacific. The density of C. nematifera (average ± standard deviation) is 2.02 ± 5.03 colonies per 100 m2 (present at 12/15 survey stations) with the number of colonization belonging to diameter group 5–20 cm. They invade 30 species belonging to 23 genera of Scleractinia corals (44.7% on foliose/laminar and encrusting coral, 23.86% on massive coral and 21.97% on branching coral). The ability to invade corals of C. nematifera does not limit the host. So, this is considered a potential hazard to the East Vietnam Sea coral reefs in the future.

ĐÁNH GIÁ TÀI NGUYÊN KHÍ HẬU VÙNG BIỂN CÔN ĐẢO VIỆT NAM THÔNG QUA CHỈ SỐ KHÍ HẬU DU LỊCH (TCI)

This article assesses climatic conditions for tourism by using Tourism Climate Index - TCI, published by Mieczkowsk (1985). This is an experimental synthetic climatic index that evaluates simultaneously the influence of 7 climatic elements as maximum average temperature (oC), minimum average humidity (%), average temperature (oC), average humidity (%), the number of sunny hours, windy speed of Con Dao island. The results of TCI within 12 months in Con Dao island compare to “Classification of advantageous levels of climate for tourism” of TCI (Mieczkowsk, 1985) which shows the advantages of Con Dao for relaxation tourism all year round. The period from December to April is the most favourable time for tourism activities in Con Dao because the TCI index reaches from Good to Very good, while the suitable time is from May to November, due to rainfall and high speed of wind during the rainy season.

Socio-hydrology: A key approach for adaptation to water scarcity and achieving human well-being in large riverine islands

Rapid global changes (population growth, urbanization and frequent extreme weather conditions) have cumulatively affected local water bodies and resulted in unfavorable hydrological, ecological, and environmental changes in the major river systems. Particularly, communities in isolated riverine islands are heavily affected due to their poor adaptive capacities, which is well documented in the contemporary literature. The focal point for the vulnerability of these people lies in the water resources (drinking water availability, agricultural water quality, salt-water intrusion, flooding etc.) and the future interaction between human and water systems. This paper advocates the importance of socio-hydrological research in the context of enhancing social adaptive capacity as well as for developing a resilient water environment in three very large riverine islands in Asia: Fraserganj (India), Dakshin Bedkashi (Bangladesh) (both from the Ganges-Brahaputra-Meghna Delta) and Con Dao Island (Mekong River, Vietnam). It also explores how the nexus of human–water relations could be applied to improve adaptive measures to manage local water needs while mitigating undesirable changes to the hydrological cycle. Socio-hydrological models as an integrated tool can be used to quantify the feedbacks between water resources and society at multiple scales, with the aim of expediting stakeholder participation for sustainable water resource management. The proposed idea in this study will be helpful to sketch projections of alternatives that explicitly account for plausible and co-evolving trajectories of the socio-hydrological system, which will yield both insights into cause–effect relationships and help stakeholders to identify safe functioning space.

Reef fish fauna in the coastal waters of Vietnam

During the last few decades, several studies relating to coral reef fishes in Vietnam have been conducted and published for individual coral reefs along the coast and offshore islands. However, no attempts have been made to compile a list of all known reef fish species from the area or to examine patterns of reef fish biodiversity across Vietnam. To address this issue, we assembled a comprehensive species distribution data set of coral reef fishes from the 23 major locations of coral reefs in the coastal waters of Vietnam. A total of 1049 species belonging to 362 genera and 91 families of reef associated fishes are currently known from the area. The 14 most-speciose families, which account for 67.8% of the total reef fish fauna, were Pomacentridae (110 species), Gobiidae (107), Labridae (100), Apogonidae (60), Serranidae (47), Blenniidae (46), Chaetodontidae (41), Scaridae (36), Scorpaenidae (32), Acanthuridae (30), Muraenidae (29), Lutjanidae (26), Carangidae (26), and Holocentridae (21). The central to southeast Vietnam (from Con Co island to Con Dao islands) supported higher species numbers compared to those on the western side of the Tonkin Gulf and the Thailand Gulf. A zoogeographic analysis reveals three distinct groups of reef fishes, in which the southern area supported 3–4 times higher numbers than the northern area and the southwestern area.

Erratum to: An Inventory and Decadal Changes of the Benthic Marine Flora on the Con Dao Islands, South China Sea, Vietnam

erratum