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Article

Community Structure, Health Status and Environmental Drivers of Coral Reefs in Koh Seh Island of the Kep Archipelago, Cambodia

by
Srey Oun Ith
1,2,†,
Amick Haissoune
2,
Alex Reid
2 and
Ratha Sor
3,*,‡
1
Centre for Biodiversity Conservation, Royal University of Phnom Penh, Russian Confederation Blvd, Phnom Penh 12000, Cambodia
2
Marine Conservation Cambodia, Koh Seh, Kep City 220201, Cambodia
3
Graduate School and International Relation and Cooperation, National University of Cheasim Kamchaymear, National Road No. 8, Kamchaymear District, Prey Veng City 14156, Cambodia
*
Author to whom correspondence should be addressed.
†
Current address: Wild Earth Allies (WEA)-Cambodia, #77A, Street Betong, Krong Thmey Village, Sangkat Kouk Khleang, Khan Saensokh, Phnom Penh 12000, Cambodia.
‡
Current address: Biodiversity and Science Unit, Conservation International-Cambodia, Phnom Penh Center, Building F, 3rd Floor, Room 259, Phnom Penh 12300, Cambodia.
J. Mar. Sci. Eng. 2025, 13(9), 1644; https://doi.org/10.3390/jmse13091644
Submission received: 14 July 2025 / Revised: 21 August 2025 / Accepted: 25 August 2025 / Published: 27 August 2025
(This article belongs to the Special Issue Marine Biota Distribution and Biodiversity)
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Abstract

Coral reef ecosystems are home to diverse marine flora and fauna. However, these ecosystems are threatened by an array of environmental and anthropogenic factors. Here, we investigated coral reef diversity, structure, and health status, and identified their key environmental drivers. Coral reef data were collected from Koh Seh Island, located inside the Marine Fisheries Management Area in the Kep archipelago. We found that the reef cover largely comprised live corals (64%, mainly Porites and Tubinaria species), followed by Zoanthids (15%) and sand/rubble (15%). Based on Ward’s hierarchical cluster analysis, coral communities were grouped into three zones: East, South, and West zones. Coral diversity was slightly higher in the East zone, though not statistically significant. Zone East showed a positive association with sediment loads and water temperature. Elevated levels of salinity, dissolved oxygen, and pH were characteristic of the East and South zones, whereas the West zone was distinguished by deeper water conditions. We also found that Favites was the key indicator for coral communities in the East zone, which features shallow, high-DO, high-pH waters with more sediments, strong currents, and significant human activities like fishing and transportation. Goniastrea species were abundant in the South and East zones, making it the indicator taxon, while the West zone had no indicator, suggesting that coral species are sparse in this zone. Interestingly, only a few dead corals were found, and no signs of diseases were detected around the Koh Seh coral reefs. This may reflect the effectiveness of joint protection efforts by Marine Conservation Cambodia and the Marine Fisheries Department in Kep province. Overall, our study provides a valuable baseline for assessing future changes in benthic reefs and coral communities on Koh Seh island, throughout the Kep Archipelago and its surrounding areas.

1. Introduction

Coral reefs are highly diverse marine ecosystems that provide foraging and refuge habitats for a highly diverse array of marine species and are thus often regarded as the “rainforests of the sea” [1]. Reefs can protect the shoreline from storms, waves, and fluctuating currents, and serve as a breeding and feeding ground for an estimated 1 million species [1]. Reefs are also a source of livelihood for local fishing communities [2]. For instance, McMannus [3] estimated that an average of 15 tons of fish and other seafood per km2 can be harvested if the resource is well-managed, whilst 30,000 to 50,000 tons of fish are collected from Cambodia’s coastal area [4]. These ecosystem services, such as fisheries, food security, coastal protection, biodiversity, and habitat provision, can therefore benefit coastal regions across the globe and as well as in Cambodia [5].
Direct localized threats have altered coral reef community structures and marine ecosystem function, while indirect global stressors associated with environmental changes continue to become increasingly severe [1]. The health and distribution of reef-building corals are influenced by environmental conditions such as climate, biochemistry, and fishing pressure [6]. In Cambodia, illegal fishing poses one of the most immediate threats to coral reefs. For instance, trawling and push nets are the most frequent fisheries crimes [7], and overfishing and bycatch comprises up to 80% [8]. Consequently, conservation efforts have largely focused on assessing the status of threatened reef systems and delivering fisheries management tools to protect wider ecosystem networks [7,9]. However, to protect marine biodiversity and promote sustainable resource use, the creation of Marine Fisheries Management Areas (MFMAs) and their effective management are key for the sustainable use of the marine resources and long-term conservation of high biodiversity areas, such as coral reefs or habitats containing endemic species [2]. These management efforts, including the enforcement of its regulations and approaches, are also important to provide education and training to communities on conserving marine biodiversity and fisheries [10]. Since these initial MFMA designations, Cambodia has continued to promote marine conservation and management through collaboration between the government, NGOs, and communities.
However, the impacts of local environmental conditions on reef systems in Cambodia have not been afforded the same research attention. By understanding the effects of physical and chemical parameters on coral community structure, local drivers—beyond anthropogenic threats such as fishing and coastal development—that influence coral health and distribution can be better identified. Furthermore, by identifying relationships between coral and environmental variables, one can gain an initial insight into how coral reefs in Cambodia will respond to future conditions under the environmental change phenomena. Here, in the Koh Seh reef system, situated in the shallow coastal water of Cambodia, we (i) investigated coral reef diversity and community structure (richness, abundance, Shannon diversity), (ii) assessed coral health status, and (iii) identified environmental drivers shaping community composition.

2. Materials and Methods

This study was conducted on the Koh Seh reef in Cambodia’s Kep archipelago (Figure 1). Koh Seh reef fringes a small island in the archipelago, which is a part of a cluster of reefs surrounding the archipelago’s islands. In addition, Koh Seh reef is a protected area of the Kep MFMA that was established in 2018. Before the undertaking of fieldwork, a desktop review was conducted to assess the extent of the Koh Seh reef and its surroundings. This review allowed the authors to map the reef using ArcGIS (v3.4.0) and design the sampling strategy, including transect numbers and spacing. The sampling area was then identified, with transect breaks in the southern sandy areas set according to reef structure and accessibility, ensuring that breaks were not shorter than elsewhere, though they could be larger (Figure 1).

2.1. Sampling Design and Data Collection

2.1.1. Substrate and Coral Cover

Data were collected between 25 June and 25 September 2019, across 16 sampling sites established around the island. The number of sites selected was proportional to the total extent of the island’s reef habitat. Each site was represented by a 50-m line transect, along which 11 quadrats measuring 0.5 m2 were placed at five-meter intervals, starting from the beginning to the end of the transect (Figure 1). Surveys were carried out at depths ranging from 1 to 2.5 m, based on the reef structure. The break between transects was approximately 65 m, with wider gaps in areas characterized by sandy bottom habitats, particularly in the southern section (Figure 1). SCUBA divers deployed the quadrats along each transect and recorded GPS coordinates at the first quadrat of each transect.
For each quadrat, a single photograph covering the entire quadrat was taken using an Olympus Tough TG-5 (Olympus Corporation, Tokyo, Japan) waterproof camera. The photographs were used to aid in the identification of corals to the genus level, and to analyze the percentage of benthic reef cover and ecological health (measured as the percentage of dead, bleached, and/or diseased coral compared to healthy coral). The photograph analysis was conducted using the software CPCe version 4.1 (Coral Point Count with Excel extensions). The key feature of using CPCe is its ability to automatically generate Microsoft Excel analysis spreadsheets with high reliability based on the identified coral and substrate data [11]. Benthic reef components were categorized into substrate types: hard coral, soft coral, sponge, rock, sand, zoanthid, macro-algae, and crustose coralline algae. For each image, 50 random points were generated in CPCe, and each point was assigned a substrate type and health status based on what it landed on.
In total, 176 quadrats (176 photographs) were surveyed across the 16 line transects, resulting in the analysis of 8800 CPCe data points (176 photographs × 50 points).

2.1.2. Physical-Chemical Variables and Sedimentation Rate Calculation

Water quality sampling (dissolved oxygen, pH, and salinity) was undertaken at the starting point (i.e., at zero meters) and at the end point of each transect line. An Automatic Temperature Compensation (ATC) meter, with additional instrumentation fitted (including a HI 9146 Microprocessor, Hanna Instruments, Woonsocket, RI, USA) was used to measure water temperature, pH, salinity, and dissolved oxygen. Depth of coral reef habitat was also measured at each transect line using a Mares Matrix dive computer.
To assess sedimentation rate, sediment traps were deployed at one end of each survey transect. Sediment traps were made from white plastic bottles and sediment trap blocks, measuring 15 × 6.5 cm with a mouth diameter of 5 cm. Each trap weighed 9 kg, which was identified as an appropriate weight for remaining stable on the sea floor through a pilot trial. Sediment traps were left in the water for one week before being sealed underwater (to prevent loss of sediment from traps) and then recovered. On land, sediment was removed from traps, placed into separate jars and sent to the laboratory at the Royal University of Phnom Penh. At the lab, sediment from each jar was filtered through size 97 g/m2 filter paper and then dried at a temperature of 25 °C for three days. The dry weight (in grams) of each sample was then measured.

2.1.3. Data Analysis

Survey data were analyzed to determine percent substrate cover and composition of coral genera. Ward’s hierarchical clustering method was used to group coral community data from all 16 sites into clusters (i.e., zones) by applying the Bray–Curtis dissimilarity distance matrix [12] using the “vegan” package of R [13]. Before performing this cluster analysis, a Hellinger transformation was undertaken to normalize the coral data and reduce effects of outliers. The result of this analysis can demonstrate which parts of the island are similar or distinct based on the coral communities. Kruskal–Wallis tests were used to test significant differences in coral diversity (e.g., richness, abundance, and diversity index) and reef covers between clusters/zones. Diversity was measured using the Shannon diversity index (Diversity H). Pairwise analysis was conducted following the significant results of the Kruskal–Wallis test.
Multi-level pattern analysis was applied to identify species indicators within each cluster/zone [14]. We used the Indicator Value (IndVal) developed by Dufrene and Legendre [15] and later improved using the function “multipatt” in the R package “indicspecies” [16] to identify indicator taxa for coral communities within the defined clusters. A taxon’s Indicator Value is a 0–1 index showing its importance in a group of sites, with 0 being least and 1 being most important. A value of 1 results if the taxon is present only in the group and when it occurs in all sites of that group. The high number of taxa showing significant indicator values suggests their preferred habitat [17]. We selected the highly significant taxa for each cluster by retaining only those with high indicator values and a p < 0.01.
A non-metric Multidimensional Scaling (NMDS) was used to visualize coral communities in a two-dimension plot to illustrate differences in community composition and fitted with the standardized environmental variables, due to different measurements, to identify their associations with the coral community composition using the function “envfit” from “vegan” R package. PERMANOVA was finally used to detect any significant variation of coral communities between clusters grouped by the Ward’s hierarchical clustering method. Data were analyzed using R statistical program version R 4.2.3 [18]. In all cases except for the indicator taxa above, the significance level was set at p < 0.05.

3. Results

3.1. Substrate Covers and Coral Community Organization

Average substrate cover was 64% dominated by live hard corals, followed by Zoanthids (15%) and sand/rubble (15%). Other substrate types exhibited relatively low levels of cover in comparison and are presented in Figure 2.
In total, 409 live hard coral colonies were recorded, belonging to 14 genera and 9 families (Scleractinia). Only one soft coral colony (Octocorallia) was observed, and the species was not able to be determined. Of the 14 hard coral genera, Porites was the most common genus across the reef system (56.6% of all corals), followed by Tubinaria (13.3%). Acropora was the least prevalent genus, comprising <1%. Diversity of coral genera along transect lines ranged from 4 to 10 genera, 12 to 40 colonies, and 0.1 to 1.9 on the Diversity H. Most hard coral growth forms were massive, which included species forms of Porites, Favites, Dipsastraea, Goniastrea, Platygyra, and Goniopora.
Based on the Bray–Curtis dissimilarity and the hierarchical analysis of the live hard corals, the 16 sites were grouped into three clusters, hereafter referred to as zones (Figure 3). The clusters represent the organization of coral communities in the East, South, and West zones. The East zone consisted of four sites located in the eastern part of the island. The South zone was made up of three sites in the southern and one site in the eastern parts of the island, whereas the West zone comprised six sites located in the western part and one site in the northern part of the island (Figure 3). The NMDS ordination plot also shows distinct coral communities among the three zones around the Koh Seh island. The East zone is characterized by high values of sediment loads, water temperature and pH; West zone is characterized by deep water, while some sites of the East and South zones are associated with high levels of pH, dissolved oxygen and salinity (Figure 4).
The PERMANOVA test yielded a highly significant difference in the variation of the coral communities in the three zones (F = 7.4, p = 0.0009), from which the East, South and West zones respectively explained 47% (p = 0.0009), 19% (p = 0.008) and 28% (p = 0.0009) of the community variation. Coral communities within the East zone are less similar to those within the South and West zones (Figure 4).
Based on the Kruskal–Wallis analysis, coral communities were not significantly different in richness, abundance and diversity H, or reef cover among the three zones (Table 1). However, we found them different in terms of indicator taxa. Favites was the indicator taxa identified within the East zone (IndVal = 0.98, p = 0.005), Goniastrea was identified as the indicator for both the South and East zones (IndVal = 0.94, p = 0.01) (Figure 4). There was no indicator found for the West zone.

3.2. Health Status and Environmental Characterization of Coral Communities

Among the reef covers, live hard corals comprised 64%, with an average of 51%, 63% and 73% for the East, South and West zones, respectively (Table 1). Only 4% of the corals were found dead, with an average of 6%, 3% and 3% for the East, South and West zones, respectively, and no diseased corals were detected. The percentage of dead coral was not significantly different between the three zones (Table 1).
We found that most of the environmental variables, except for salinity, showed significant differences among the three zones. Dissolved oxygen and water depth had a highly significant difference (p < 0.001), while the others like sediment loads, water temperature and pH were significantly different at p < 0.05. Detailed information on the environmental variables characterizing each reef zone is provided in Table 2.

4. Discussion

4.1. Reef Cover and Coral Community Organization

In Cambodia, coral reef communities are typically dominated by hard corals, with soft corals generally showing lower diversity and abundance. This pattern, observed at Koh Seh, aligns with previous surveys in nearby archipelagos. High sedimentation, temperature fluctuations, and variable water quality may reduce light availability and increase physiological stress, making inshore reefs less favorable for soft corals [19,20]. Further targeted studies are needed to confirm these drivers [21]. The dominance of Porites at Koh She, as well as in Koh Rong [9,22] and Koh Sdach [21], suggests that massive growth forms are particularly successful in turbid, nearshore environments [23,24]. Their tolerance to sedimentation and fluctuating conditions may explain why they consistently dominate Cambodian reefs. Comparable dominance of massive Porites has also been reported in Indonesia’s Karimunjawa Islands [25], reinforcing the idea that Porites are well adapted to marginal reef environments across the Indo-Pacific [26,27].
Despite environmental heterogeneity among zones, overall diversity metrics did not differ significantly. This homogeneity may reflect the small spatial scale of Koh Seh and the long-term establishment of resilient coral taxa across the reef, as also noted in Koh Rong and Koh Sdach [28]. Indicator species analysis revealed distinct assemblages, particularly in the East zone where Favites and Goniastrea dominated. These genera are known to tolerate shallow, turbid conditions [3], supporting the view that community composition is structured by local environmental filtering rather than broad-scale diversity differences [26].

4.2. Health Status and Environmental Drivers

The very low incidence of disease, bleaching, and mortality indicates that Koh Seh reefs are currently in good condition. This resilience is likely linked to the dominance of massive, stress-tolerant taxa (e.g., Porites, Favites, Goniastrea), which are known to withstand environmental fluctuations better than branching forms [9]. Similar dominance of massive forms in Koh Rong and Koh Sdach suggests a regional pattern of resilience in marginal reefs [21] (Table 3). The relatively healthy condition at Koh Seh may also reflect effective protection under the MFMA, highlighting the importance of continued monitoring and enforcement. Targeted protection is especially relevant in the East zone, where reefs are exposed to high sedimentation, strong currents, and human pressures such as fishing and boat traffic [8]. Sustained enforcement could help mitigate these stressors and maintain resilience.
Environmental factors usually affect coral community composition. These factors can be anthropogenic disturbances, temperature, pH, salinity, dissolved oxygen, water depth, and sediment [25,29]. Experimental studies confirm that coral physiology is sensitive to temperature, turbidity, salinity, and dissolved oxygen [29,30]. The significant variation of these parameters among Koh Seh zones may therefore explain the observed shifts in community composition.
Sediment loads were highest in the East zone, likely reflecting strong currents, fishing activity, and coastal development [8,31]. Such conditions typically disadvantage branching taxa like Acropora but favor massive, sediment-tolerant corals such as Favites and Goniastrea [32,33,34,35,36,37]. This pattern mirrors findings from other turbid reef systems (e.g., Thailand, Malaysia, Puerto Rico) [36], emphasizing that sedimentation is a primary driver of community composition in marginal reefs [38,39].
Changes in salinity can significantly influence coral community composition, primarily by reducing fertilization success and impairing larval development, which in turn affects coral growth, reproduction, and survival [40]. In our study, salinity was lowest in the West zone, where Goniopora were more common. This may reflect their greater tolerance to salinity fluctuations, with Goniopora potentially benefiting from cooler, deeper water conditions [41,42].
While our study provides an important baseline, further surveys across larger spatial and temporal scales are needed to capture rare taxa, recruitment events, and interannual variability, which would strengthen assessments of reef health and resilience [43,44]. Small sample size can only provide an area-specific coverage generalization, as of the present study, because coral reefs are highly heterogeneous and inter-annual varied.

5. Conclusions

This study is the first detailed investigation of coral reefs and diversity in Koh Seh of the Kep Archipelago. We found that live hard corals are the dominant component of the benthic reef covers, followed by Zoanthids and sand and rubble. All hard corals around Koh Seh were grouped into three zones: East, West and South zones. The East zone showed higher coral diversity, though not significantly, and was mainly associated with warmer temperatures and higher sediment loads. Elevated salinity, dissolved oxygen, and pH were the characteristics of both the East and South zones, while the West zone was characterized by deeper waters. The Genus Favites was the key indicator in the East zone, which experienced strong currents, shallow waters, and human activities. The genus Goniastrea was common in the South and East zones, making it the indicator taxon for the two zones, while no indicator species were found in the West zone, suggesting low occurrence of coral communities. Nevertheless, we observed a small proportion of dead and diseased coral colonies around the island, suggesting that collaborative management efforts by the Marine Conservation Cambodia and the Marine Fisheries department of the Ministry of Agriculture in Kep province are contributing positively to reef health. Taken as a whole, our study provides a useful baseline for further research on benthic reefs and coral communities across the Kep Archipelago and surrounding areas.

Author Contributions

Conceptualization: S.O.I. and R.S.; Methodology: S.O.I., R.S. and A.H.; Data collection: S.O.I. and A.H.; Formal analysis and investigation: S.O.I. and R.S.; Writing—original draft preparation: S.O.I. and R.S.; Writing—review and editing: All; Funding acquisition: A.H.; Supervision: R.S. and A.H.; Visualization: S.O.I. and R.S. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Marine Conservation of Cambodia.

Data Availability Statement

The data can be obtained by official request to the corresponding author.

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. Study area and sampling design. “T” denotes line transects representing the sampling sites, each consisting of 11 quadrats. The numbers after letter “T” denote each transect line number.
Figure 1. Study area and sampling design. “T” denotes line transects representing the sampling sites, each consisting of 11 quadrats. The numbers after letter “T” denote each transect line number.
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Figure 2. Pie charts showing the percentage of substrate covers (left) and coral genera (right) on the Koh Seh reef.
Figure 2. Pie charts showing the percentage of substrate covers (left) and coral genera (right) on the Koh Seh reef.
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Figure 3. Dendrogram of the cluster analysis revealing three distinct clusters representing three zones (left) based on the Bray–Curtis dissimilarity and Ward’s hierarchical clustering method and a map showing sites belonging to the three zones (right). The color of each dendrogram branch represents coral communities inhabiting in each zone represented by the same line color—the West (black line), East (red line), and South (blue line) zones. The letter “T” and its following numbers represent the transect lines.
Figure 3. Dendrogram of the cluster analysis revealing three distinct clusters representing three zones (left) based on the Bray–Curtis dissimilarity and Ward’s hierarchical clustering method and a map showing sites belonging to the three zones (right). The color of each dendrogram branch represents coral communities inhabiting in each zone represented by the same line color—the West (black line), East (red line), and South (blue line) zones. The letter “T” and its following numbers represent the transect lines.
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Figure 4. NMDS ordination plot showing the spatial coral community organization, the West (black line), East (red line), and South (blue line) zones, and their association with environmental variables. The corals in bold and underlined are the identified indicator taxa. The letter “T” and its following numbers represent the transect lines.
Figure 4. NMDS ordination plot showing the spatial coral community organization, the West (black line), East (red line), and South (blue line) zones, and their association with environmental variables. The corals in bold and underlined are the identified indicator taxa. The letter “T” and its following numbers represent the transect lines.
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Table 1. Mean value ± standard deviation for richness, abundance, and diversity H, and percentage substrate cover in each zone. n: number of sampling sites.
Table 1. Mean value ± standard deviation for richness, abundance, and diversity H, and percentage substrate cover in each zone. n: number of sampling sites.
Cluster or Zone [n]
VariablesEast Zone [5]South Zone [4]West Zone [7]p-Value
Coral Community
Richness7.2±2.46.8±2.16.1±1.90.673
Abundance28.8±10.823.0±8.824.9±3.30.351
Diversity H1.7±0.31.6±0.31.3±0.30.129
Benthic Reef Cover (%)
Live hard corals51.0±34.463.0±24.173.2±22.70.417
Sponges0.0±0.00.0±0.00.6±1.50.525
Zoanthids27.5±21.719.5±18.65.8±9.50.147
Dead coral5.5±10.43.0±6.02.9±7.60.643
Coralline algae0.0±0.05.5±11.00.0±0.00.223
Sand and Rubble16.0±17.29.0±6.217.5±19.30.929
Table 2. Mean value ± standard deviation of environmental variables in each zone. n: number of sample sites belonging to each zone.
Table 2. Mean value ± standard deviation of environmental variables in each zone. n: number of sample sites belonging to each zone.
Cluster [n] or Zone
VariablesEast Zone [5]South Zone [4]West Zone [7]
DO (%) ***96.5±1.9 a97.2±1.4 a88.5±9.0 b
Temperature (°C) *30.0±0.7 a29.5±0.6 a29.0±0.0 b
pH *8.2±0.1 a8.1±0.1 a7.7±0.4 b
Salinity (ppt)33.3±0.733.3±0.528.3±5.1
Sediment (g) *26.8±37.9 a14.9±8.3 a14.6±32.2 b
Water Depth (m) ***1.0±0.4 a2.0±0.2 a2.5±0.4 b
*: p < 0.05, ***: p ≤ 0.001; ppt: part per thousand. The different upper lower-case letters indicate pairwise significant difference between zones.
Table 3. The mean percentage cover of two common reef health indicators of the present study (Koh Seh) compared to Koh Sdach [21] and Koh Rong archipelagos [9].
Table 3. The mean percentage cover of two common reef health indicators of the present study (Koh Seh) compared to Koh Sdach [21] and Koh Rong archipelagos [9].
IndicatorsKoh Seh (%)Koh Sdach (%)Koh Rong (%)
Live hard coral cover63.763.726.8
Dead/killed coral3.85.05.7
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Ith, S.O.; Haissoune, A.; Reid, A.; Sor, R. Community Structure, Health Status and Environmental Drivers of Coral Reefs in Koh Seh Island of the Kep Archipelago, Cambodia. J. Mar. Sci. Eng. 2025, 13, 1644. https://doi.org/10.3390/jmse13091644

AMA Style

Ith SO, Haissoune A, Reid A, Sor R. Community Structure, Health Status and Environmental Drivers of Coral Reefs in Koh Seh Island of the Kep Archipelago, Cambodia. Journal of Marine Science and Engineering. 2025; 13(9):1644. https://doi.org/10.3390/jmse13091644

Chicago/Turabian Style

Ith, Srey Oun, Amick Haissoune, Alex Reid, and Ratha Sor. 2025. "Community Structure, Health Status and Environmental Drivers of Coral Reefs in Koh Seh Island of the Kep Archipelago, Cambodia" Journal of Marine Science and Engineering 13, no. 9: 1644. https://doi.org/10.3390/jmse13091644

APA Style

Ith, S. O., Haissoune, A., Reid, A., & Sor, R. (2025). Community Structure, Health Status and Environmental Drivers of Coral Reefs in Koh Seh Island of the Kep Archipelago, Cambodia. Journal of Marine Science and Engineering, 13(9), 1644. https://doi.org/10.3390/jmse13091644

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