Coral Diversity Research Articles

Advancing Coral Structural Connectivity Analysis through Deep Learning and Remote Sensing: A Case Study of South Pacific Tetiaroa Island

Abstract. Structural connectivity is an important factor in preserving coral diversity. It maintains the stability and adaptability of coral reef ecosystems by facilitating ecological flow, species migration, and gene exchange between coral communities. However, there has always been a lack of consistent solutions for accurate structural connectivity describing and quantifying, which has hindered the understanding of the complex ecological processes in coral reefs. Based on this, this paper proposes a framework that uses advanced remote sensing and deep learning technologies to assess coral structural connectivity. Specifically, accurate coral patches are firstly identified through image segmentation techniques. And the structural connectivity is quantified by assessing the connectivity patterns between and within these coral patches. Furthermore, Tetiaroa Island in the South Pacific is used as a case study to validate the effectiveness and accuracy of the framework in assessing coral structural connectivity. The experimental results demonstrate that the framework proposed in this paper provides a powerful tool for understanding the internal ecological processes and external spatial patterns of coral reef ecosystems, thereby promoting scientific understanding and effective management of coral reef conservation.

The diversity, distribution, and temporal stability of coral ‘zooxanthellae’ on a pacific reef: from the scale of individual colonies to across the host community

The diversity, distribution, and temporal stability of coral ‘zooxanthellae’ on a pacific reef: from the scale of individual colonies to across the host community

Taxonomic and functional diversity of zooxanthellate corals and hydrocorals in Southwestern Atlantic reefs

The Southwestern Atlantic (SWA) harbors a relatively species poor but highly endemic coral assemblage due to historical processes, environmental and ecological drivers. Despite its low to moderate cover, corals still have a disproportionate contribution to ecosystem function and stability in this region. In the context of global change, it is imperative to know corals’ diversity and biogeographic patterns, yet a comprehensive approach is still missing for SWA corals. We integrated occurrence data from 21 sites and nine functional traits across 20 coral (scleractinian and hydrozoan) species to explore the taxonomic and functional diversity of coral assemblages in the SWA (1°N-27°S). We identified eight regions based on coral species composition, and then described their functional diversity using four metrics: functional richness (FRic), functional dispersion (FDis), functional evenness (FEve), and functional originality (FOri). Taxonomic and functional diversity peak between latitudes 13°S-20°S, decreasing with increasing distance from this diversity center, known as the Abrolhos Bank that harbors a wide continental platform. Our findings reveal a prevalent pattern of high functional redundancy across these eight regions (indicated by low functional originality), with species occupying the edges of the trait space (high functional evenness) and converging around few trait values (low functional dispersion). Such patterns resulted in low taxonomic and functional beta diversity and increased nestedness among regions caused by dispersal barriers and environmental filtering. The Southernmost region (24°-27°S) has the lowest taxonomic and functional diversity and comprises only two species that share similar traits, with these corals being: hermaphrodites, brooders and depth-tolerant, and having a wide corallite. As this region might become critical for corals in a future tropicalization scenario, tropical corals that share similar traits to those of the southernmost region can be more likely to thrive. Knowledge on taxonomic and functional diversity patterns can offer critical information to conservation by helping prioritizing areas with higher diversity and species with traits that enhance survival under climate change.

Molecular diversity of black corals from the Saudi Arabian Red Sea: a first assessment.

Black corals occur as part of benthic assemblages from shallow to deep waters in all oceans. Despite the importance in many benthic ecosystems, where these act as biodiversity aggregators, antipatharians remain poorly studied, with 75% of the known species occurring below recreational SCUBA diving depth limits. Currently, information regarding the diversity and evolutionary history is limited, with most studies focusing on Hawaii and the South Pacific Ocean. Other regions of the world have received less attention, such as the Red Sea, where only two black coral families and four genera have been recorded. We provide the first analysis of the molecular diversity of black corals in the eastern Gulf of Aqaba and the northern and central Saudi Arabian Red Sea, based on a dataset of 161 antipatharian colonies collected down to 627 m deep. Based on specimen morphology, we ascribed our material to 11 genera belonging to 4 of the 7 known Antipatharia families, i.e. Antipathidae, Aphanipathidae, Myriopathidae and Schizopathidae. The genus level phylogeny of three intergenic mitochondrial regions, the trnW-IGR-nad2 (IgrW ), nad5-IGR-nad1 (IgrN ) and cox3-IGR-cox1 was reconstructed including previously published material. Overall, we recovered six molecular clades that included exclusively Red Sea sequences, with the highest diversity occurring at mesophotic depths. This study highlights that diversity of black corals in the Red Sea is much higher than previously known, with seven new generic records, suggesting that this basin may be a hotspot for antipatharian diversity as is known for other taxa. Our results recovered unresolved relationships within the order at the familial and generic levels. This emphasises the urgent need for an integration of genomic-wide data with a re-examination of informative morphological features necessary to revise the systematics of the order at all taxonomic levels.

The Coral Chronicles: Climate Crisis and Its Implications on the Global Coral Reefs

The coral reefs are one of the most devastating causalities that is often overlooked as our planet grapples with the continually progressing crisis of climate change. They are often addressed as the rainforests of the sea and are hubs of biodiversity that support a one-fourth of all marine species even though they only cover less than one percent of the ocean floor. Not only are they inhabiting countless marine creatures, they are also a crucial food an income source to the millions of people worldwide. Alas! These vibrant underwater ecosystems are being pushed to the brink of collapse due the relentless onslaught of climate change. 
 Consider the Great Barrier Reef, off the coast of Australia, where extensive coral bleaching events are occurring due to rising sea temperatures [1]. The threat of ocean acidification has jeopardized the coral reef in the Maldives and is potentially affecting the country economically which is based on the tourism and fisheries. Likewise, Caribbean Sea is facing disease outbreak and coral bleaching. Philippines is home to some of the most diverse coral reefs in the world but, climate change, overfishing and coastal development is threatening these natural ecosystems. Apart from these, Seychelles and Mauritius in the Indian Ocean and the Coral triangle in the Southeast Asian region are also at stake due to these environmental stressors [2]. 
 In the face of these challenges, many governments, NGOs and local communities have united to conserve these global reefs. Different Marine Protected Areas (MPAs) have been developed to mitigate overfishing and habitat destruction and protect the coral reefs [3]. Moreover, many techniques have been developed to restore the degraded coral ecosystems and enhance their resilience, including Coral Transplantation and Artificial Reef Structures. These initiatives have created the hope that the vibrant coral reefs will eventually recover in face of the existing environmental crises. 
 However, we cannot overstate that the current situation is dire and nothing short of a global calamity. It is our moral obligation that we protect and preserve these natural wonders for future generations. If we do not take immediate action to curb the emission of greenhouse gases and fight against the climate change, we risk losing these underwater ecosystems right in front of our eyes. It is our choice and the stakes could not be higher. 

Evaluation of Service Quality of Diving Tourism in Bali, Indonesia

Bali diving tourism needs to be managed properly to strengthen competitiveness in the face of increasingly fierce competition. Using a set of attributes of diving tourism, this study aims to evaluate the compatibility of the diving tourism attributes that are important to divers and the performance of these attributes and to determine the actual performance of the diving tourism attributes in Bali. Data were collected through a questionnaire survey of 236 respondents regarding the importance of the 20 diving tourism attributes and their satisfaction with these attributes. As many as 13 of the 20 diving tourism attributes in Bali performed positively, meaning that the level of satisfaction exceeded the level of importance, and only one attribute performed negatively, meaning that the level of satisfaction was lower than the level of importance. Importance-Performance analysis shows that the attributes that are the competitive strengths of Bali diving tourism are coral cover, coral diversity, water visibility, dive equipment settings, divemaster competence, safety measures, and pre-dive briefing. The attributes that become weaknesses are the fish abundance, fish diversity, megafauna, and the implementation of the diving code of conduct. Diving tourism stakeholders in Bali must focus on improving the attributes that are weaknesses and maintaining the attributes that are strengths to strengthen the competitiveness of Bali diving tourism in the future.

Assess the level of damage to the coral reef ecosystem based on substrate coverage on Bira Island, Kepulauan Seribu, Indonesia

Abstract. Komala R, Noer MI, Miarsyah M, Widyartini DS, Handayani. 2024. Assess the level of damage to the coral reef ecosystem based on substrate coverage on Bira Island, Kepulauan Seribu, Indonesia. Biodiversitas 25: 971-977. Coral reefs are coastal ecosystems that have an important ecological and economic role. Environmental pressures cause damage to ecosystems and decrease coral biodiversity. This study aims to analyze the level of damage to coral reef ecosystems based on substrate cover and obtain the latest information on coral reef ecosystem resources. The study employs a descriptive method with a survey design, utilizing Underwater Photo Transect (UPT) sampling at various depths along the coastline. The data is analyzed using Coral Point Count with Excel extension (CPCe) for substrate cover percentage and the Shannon-Wienner index for coral diversity. The findings reveal nine categories of basic substrate cover, with living hard corals constituting 32.51%, indicating a fairly damaged state. Coral resources are identified across 53 genera and 15 families, exhibiting medium diversity across stations and depths. The study highlights the need to monitor environmental threats that could further damage coral reefs and decrease diversity. The coral reef ecosystem in Bira Island is in a relatively damaged condition, with a decline in coral biodiversity, indicating an imbalance in the ecosystem. Several recommended steps include implementing coral restoration programs, monitoring coral growth, establishing critical coral habitat protection zones, and conducting conservation efforts.

Genomics of a novel ecological phase shift: the case of a ‘weedy’ Montipora coral in Ulithi, Micronesia

Local and global ecological stressors are leading to increased documentation of phase shifts in coral reefs from healthy stony corals to macrophytes. In more rare cases, phase shifts result in sponge, zoantharian or other dominant species. In Ulithi Atoll, Federated States of Micronesia, we have documented an unusual phase shift from reefs with a diverse stony coral assemblage to reefs dominated by a single species of stony coral: Montipora sp.—a coral-to-coral phase shift. This monospecific type of reef lowers fish diversity and biomass, impacting both ecological integrity, and livelihoods of reef-dependent human communities. In this study, we used a genomic approach to characterize such a reef. We assembled a de-novo reference genome and used RAD seq data with thousands of SNPs to determine if different reefs result from sexual or asexual reproduction, if weedy Montipora fragments are transported between islands by human activities, and if there is evidence of natural selection on specific genotypes, thus favoring spreading success. We found that sexual reproduction is predominant in the focal species, that there is no evidence of human-mediated spread, and that some genomic regions might be under selection. While such results eliminate a number of spreading hypotheses, more precise dispersal maps will be important to determine the tempo and mode of ‘invasion’ of Montipora in Ulithi Atoll. This study shows that selection and adaptation may be contributing to the success of a stony coral (e.g., Phase shift). While a stony coral may be successful in a disturbed environment, it does not necessarily provide the type of habitat that is conducive to high fish biomass and coral diversity. These results serve as a cautionary tale for restoration efforts that focus on single species coral resilience rather than ecosystem function.

Mitigation of Vibrio coralliilyticus-induced coral bleaching through bacterial dysbiosis prevention by Ruegeria profundi.

Vibrio species are prevalent in ocean ecosystems, particularly Vibrio coralliilyticus, and pose a threat to corals and other marine organisms under global warming conditions. While microbiota manipulation is considered for coral disease management, understanding the role of commensal bacteria in stress resilience remains limited. Here, a single bacterial species (Ruegeria profundi) rather than a consortium of native was used to combat pathogenic V. coralliilyticus and protect corals from bleaching. R. profundi showed therapeutic activity in vivo, preventing a significant reduction in bacterial diversity in bleached corals. Notably, the structure of the bacterial community differed significantly among all the groups. In addition, compared with the bleached corals caused by V. coralliilyticus, the network analysis revealed that complex interactions and positive correlations in the bacterial community of the R. profundi protected non-bleached corals, indicating R. profundi's role in fostering synergistic associations. Many genera of bacteria significantly increased in abundance during V. coralliilyticus infection, including Vibrio, Alteromonas, Amphritea, and Nautella, contributing to the pathogenicity of the bacterial community. However, R. profundi effectively countered the proliferation of these genera, promoting potential probiotic Endozoicomonas and other taxa, while reducing the abundance of betaine lipids and the type VI section system of the bacterial community. These changes ultimately influenced the interactive relationships among symbionts and demonstrated that probiotic R. profundi intervention can modulate coral-associated bacterial community, alleviate pathogenic-induced dysbiosis, and preserve coral health. These findings elucidated the relationship between the behavior of the coral-associated bacterial community and the occurrence of pathological coral bleaching.IMPORTANCEChanges in the global climate and marine environment can influence coral host and pathogen repartition which refers to an increased likelihood of pathogen infection in hosts. The risk of Vibrio coralliilyticus-induced coral disease is significantly heightened, primarily due to its thermos-dependent expression of virulent and populations. This study investigates how coral-associated bacterial communities respond to bleaching induced by V. coralliilyticus. Our findings demonstrate that Ruegeria profundi exhibits clear evidence of defense against pathogenic bacterial infection, contributing to the maintenance of host health and symbiont homeostasis. This observation suggests that bacterial pathogens could cause dysbiosis in coral holobionts. Probiotic bacteria display an essential capability in restructuring and manipulating coral-associated bacterial communities. This restructuring effectively reduces bacterial community virulence and enhances the pathogenic resistance of holobionts. The study provides valuable insights into the correlation between the health status of corals and how coral-associated bacterial communities may respond to both pathogens and probiotics.

Deep sea treasures - Insights from museum archives shed light on coral microbial diversity within deepest ocean ecosystems

Deep sea benthic habitats are low productivity ecosystems that host an abundance of organisms within the Cnidaria phylum. The technical limitations and the high cost of deep sea surveys have made exploring deep sea environments and the biology of the organisms that inhabit them challenging. In spite of the widespread recognition of Cnidaria's environmental importance in these ecosystems, the microbial assemblage and its role in coral functioning have only been studied for a few deep water corals. Here, we explored the microbial diversity of deep sea corals by recovering nucleic acids from museum archive specimens. Firstly, we amplified and sequenced the V1–V3 regions of the 16S rRNA gene of these specimens, then we utilized the generated sequences to shed light on the microbial diversity associated with seven families of corals collected from depth in the Coral Sea (depth range 1309 to 2959 m) and Southern Ocean (depth range 1401 to 2071 m) benthic habitats. Surprisingly, Cyanobacteria sequences were consistently associated with six out of seven coral families from both sampling locations, suggesting that these bacteria are potentially ubiquitous members of the microbiome within these cold and deep sea water corals. Additionally, we show that Cnidaria might benefit from symbiotic associations with a range of chemosynthetic bacteria including nitrite, carbon monoxide and sulfur oxidizers. Consistent with previous studies, we show that sequences associated with the bacterial phyla Proteobacteria, Verrucomicrobia, Planctomycetes and Acidobacteriota dominated the microbial community of corals in the deep sea. We also explored genomes of the bacterial genus Mycoplasma, which we identified as associated with specimens of three deep sea coral families, finding evidence that these bacteria may aid the host immune system. Importantly our results show that museum specimens retain components of host microbiome that can provide new insights into the diversity of deep sea coral microbiomes (and potentially other organisms), as well as the diversity of microbes writ large in deep sea ecosystems.

Community-Based Monitoring for Rapid Assessment of Nearshore Coral Reefs Amid Disturbances in Teahupo’o, Tahiti

Nearshore coral reefs at Teahupo’o, Tahiti, are currently threatened by destruction from proposed plans to build a new judging tower in the reef lagoon for the 2024 Olympic surfing event. Local community members were trained to utilize 3D photogrammetry techniques to create high-resolution habitat maps of three sites that will be impacted by dredging and tower construction. The resulting orthomosaics were analyzed to quantify and characterize the coral community structure at each study site. Species diversity, coral colony count, coral colony size, and percent cover of live coral and living benthos were extracted from all survey plots. The resulting data show these sites support healthy and diverse coral communities that contribute to the ecological function of the larger reef system at Teahupo’o. The Hawai’i State Division of Aquatic Resources Penalty Matrix was used to estimate the USD value of the live corals and algae identified among the study sites and the total area that will be impacted by the planned development project. This study highlights the utility of 3D photogrammetry for effective citizen science as well as the large economic and ecological impacts that may occur if this proposed construction occurs.

Integrating cryptic diversity into coral evolution, symbiosis and conservation.

Understanding how diversity evolves and is maintained is critical to predicting the future trajectories of ecosystems under climate change; however, our understanding of these processes is limited in marine systems. Corals, which engineer reef ecosystems, are critically threatened by climate change, and global efforts are underway to conserve and restore populations as attempts to mitigate ocean warming continue. Recently, sequencing efforts have uncovered widespread undescribed coral diversity, including 'cryptic lineages'-genetically distinct but morphologically similar coral taxa. Such cryptic lineages have been identified in at least 24 coral genera spanning the anthozoan phylogeny and across ocean basins. These cryptic lineages co-occur in many reef systems, but their distributions often differ among habitats. Research suggests that cryptic lineages are ecologically specialized and several examples demonstrate differences in thermal tolerance, highlighting the critical implications of this diversity for predicting coral responses to future warming. Here, we draw attention to recent discoveries, discuss how cryptic diversity affects the study of coral adaptation and acclimation to future environments, explore how it shapes symbiotic partnerships, and highlight challenges and opportunities for conservation and restoration efforts.

Population Genetics Assessment of the Model Coral Species Stylophora pistillata from Eilat, the Red Sea

The successful management of coral reefs necessitates understanding the genetic characteristics of reefs’ populations since levels of genetic diversity play a critical role in their resilience, enabling them to withstand environmental changes with greater efficacy. To assess the genetic diversity and connectivity of the widespread Indo-Pacific coral, Stylophora pistillata, eight microsatellite loci were employed on 380 tissue samples collected from eight sites along the northern Gulf of Eilat, Red Sea. We documented deviations from the Hardy–Weinberg equilibrium and observed low heterozygosity and high values of expected heterozygosity (0.59 and 0.82, respectively). The relatively high FST values and STRUCTURE analysis results showed population fragmentation along the short coastline (<12 km). These results signify isolation by distance, low gene flow between most populations, and possible non-random mating. These results are connected to this species’ sexual reproduction traits, a brooding coral species with planulae that settle shortly upon release with limited connectivity that are most probably further exacerbated by anthropogenic impacts imposed on Eilat’s reefs. This study provides insights into the connectivity and population genetics of S. pistillata residing in an urbanized northern Red Sea reef and reinforces the need for better management of the current MPA, employing future active coral reef restoration in the area.

Study of Coral Reefs in the Tourism Zone of Hoga Island, Wakatobi National Park, Southeast Sulawesi, Indonesia

One of the ecosystems in tropical waters is the coral reef. Coral reefs serve multiple functions, both ecologically and economically. The marine waters in Wakatobi Regency boast diverse coral reefs, and this study aims to assess the coral reefs in one of its regions, specifically in the waters around Hoga Island, part of Wakatobi National Park. The research was conducted from March to May 2023, involving direct observations at the research site. The collected data were then analyzed and presented descriptively concerning the percentage of coral reefs in the study area. The percentage of coral cover in the growth forms (lifeform) of the Wakatobi National Park tourism zone, region II, revealed that, at the first station, coral cover was 46.33%, dominated by Coral Branching (CB) at 22.36%, and Biotic, primarily Soft Coral (SC), at 14.95%. At the second station, coral cover was 36.13%, with Coral Branching (CB) accounting for 11.53%, and Soft Coral (SC) at 25.33%. The third station exhibited a coral cover percentage of 60.37%.

Remotely sensed habitat diversity predicts species diversity on coral reefs

The ability to map coral reef biodiversity from orbit would greatly advance marine spatial planning. Presently, reef biodiversity is measured in situ by divers, but this method is inefficient and expensive. Remote sensing techniques have been developed in the terrestrial realm to lever the “habitat heterogeneity hypothesis,” which contends that the biodiversity of organisms is directly linked to the diversity of habitats which they occupy. Here, we evaluated this hypothesis using satellite-derived reef habitat maps across 880 shallow-water field stations distributed on a global transect through the Atlantic, Pacific, and Indian Oceans where we measured the taxonomic and functional diversity of reef fish and corals. Benthic habitat maps produced from WorldView-2 and PlanetScope were compared as proxies for coral reef species diversity. We found satellite-mapped habitat heterogeneity to be positively correlated with both fish (R ≤ 0.64) and coral diversity (R ≤ 0.56), at an optimum spatial scale between 110 and 320 ha, even when the data were partitioned across global biodiversity gradients. Best results were realized when using the WorldView-derived habitat maps, indicating that the enhanced spectral and radiometric resolution of this sensor is better poised for retrieving species biodiversity than PlanetScope. Our study offers an efficient method for monitoring coral reef ecosystems by leveraging satellite maps as a surrogate for species biodiversity.

Oasis of the deep: Cold-water corals of the South China Sea

Cold-water coral (CWC) communities are biodiversity hotspots on the world's deep seafloor. Although deep-sea corals in the South China Sea (SCS) have been reported before, they are only sporadic. A comprehensive and systematic understanding of the CWC in the SCS would forge the basis for future protection. Here we conducted the first systematic survey on the CWCs in the following six broad-scale sub-regions, from the northwest and northeast slopes to the seamounts in the western and central basins of the SCS, through twenty-four dives of the human-occupied vehicle ShenhaiYongshi. Statistical analysis provided detailed information on the distribution, abundance, size, diversity, and density of CWCs and the in situ environmental conditions supporting coral habitats. We found that the SCS hosted highly diversified coral communities, including twelve genera of gorgonians, six genera of black corals, and one genus of stony corals. The differences in the spatial distribution patterns of coral communities suggested that several environmental variables (depth, temperature, salinity, substrate, and geomorphology) might influence the development of CWCs in the SCS. The intermediate water layer of the SCS appeared to provide suitable habitat for deep-sea coral communities and potentially promoted connectivity. Furthermore, differences between sub-regions within the SCS may be an important factor responsible for the biogeographic patterns of CWCs. These sub-regions of CWCs were observed to range from 0.004 to 0.622 corals m−2, with an average of 0.139 corals m−2. The mean density of CWCs in the SCS was relatively high compared to well-studied CWC hotspots. Overall, the results revealed the significance of the SCS as an important CWC hotspot in the world. These findings provide a fundamental basis for the protection of deep-sea coral assemblages in the SCS.

Status of Coral reef around Swaraj Dweep (Havelock Island), Andaman, India

The study was carried out in selected reef sites at Swaraj Dweep (Havelock Island) to assess the status of live coral diversity with related fauna by using the line intercept transects (LIT) survey method. Three sites were selected for this study viz (1) Vijayanagar beach, (2) Elephant beach and (3) Radha Nagar Beach. The average length of entire LIT and reef area of each site were 1098 m, 141.3m and 215 m & 675.3 m, 103.3m and 133m respectively. The average of live corals was found dominant in the entire LIT at site 2 (37.7%) followed by site 1 (16.2%), and site 3 (14%) and dead corals were found dominant at site 3 (44.7%) followed by site 2 (33.2%) and site 1 (13.8%). Similarly reef area of live coral was found dominant at site 2 (50.8±2.5%) followed by site-1 (26.9±0.2%) and site 3 (23.7±6.2%). Altogether 80 species of live coral were recorded under 31 genera and 11 family at all LIT in which the family Poritidae was dominant in site 1 (55.1±4.9%) and site 2 (55.2±2.5%). The family Acroporidae was dominant in site 3 (35.2±4.1%). The environmental parameters of all three sites were analyzed that there were little variations observed except CO2 which remained consistent (0) during the study period.

Distribution and palaeoecology of scleractinian corals during the Maastrichtian (Late Cretaceous)

Abstract Maastrichtian scleractinian corals from 94 localities in 26 Maastrichtian regions world-wide with strata of that age are taxonomically and palaeobiogeographically evaluated. A total of 205 taxa, belonging to 116 genera and 37 families, are included in the present study. Most coral taxa have been recorded from non-reefal environments. A significant majority of these taxa (genera = 70.7%; species = 75.6%) appear to have been endemic during the Maastrichtian. The Maastrichtian coral fauna is dominated by solitary and cerioid-plocoid forms (both accounting for 41 genera = 70%), having mainly medium- and large-sized corallites. The most diverse coral assemblages are those that have been recorded from arid (Jamaica: 63 species, Mexico: 29 species), warm-temperate (the Netherlands-Belgium: 32 species) and tropical regions (Iran: 27 species). The occurrence of Cunnolites polymorphus (Goldfuss) is newly recorded for the Netherlands (southern Limburg). Compared to the microstructural composition of the coral fauna of the lowermost Cretaceous (Berriasian; 91% of the species and 83% of the genera belonged to previously established microstructural groups), in the Maastrichtian, corals belonging to previously established microstructural groups were of minor importance (genera = 26%; species = 29.3%). The majority of Maastrichtian scleractinian taxa (both solitary and colonial) from the type area of the Maastrichtian Stage in the southeast Netherlands and northeast Belgium are illustrated.

Evaluation of Coral Reef Health Status in the Fish Sanctuary of San Esteban, Ilocos Sur

Studies on corals are lacking in Ilocos Sur’s marine protected areas (MPAs), hindering management effort development. This study evaluated the health status of coral reefs in the San Esteban Fish Sanctuary. Hard coral cover, hard coral diversity in terms of Taxonomic Amalgamation Units (TAUs), and coral reef health status in terms of live coral coverage, algae coverage, sand coverage, and coral mortality index were measured in two sampling stations inside an over-a-decade-old fish sanctuary that does not have previous data on its coral reef health status. The Underwater Photo Transect (UPT) method was employed to take image samples subjected to the Coral Point Count with Excel extensions (CPCe) software for analysis. The study revealed that the coral reef in San Esteban Fish Sanctuary is in good condition with a hard coral cover of 30.0%, falls under Hard Coral Cover Category C, and a hard coral diversity of 16.8TAUs that falls under Diversity Category D. The fish sanctuary is also in a healthy condition based on excellent live coral coverage, algae coverage, sand coverage, and low coral mortality index. The two stations are more or less the same in terms of the aforementioned parameters. Overall, it is recommended to continuously strengthen the enforcement of the fish sanctuary to protect its coral reefs, measure other parameters that might impact and indicate coral reef health status, employ evaluations inside and outside MPAs in the province, and use high-resolution cameras during image sampling for more efficient analysis.

BIOLOGICAL IMPACTS OF ANCHORING ON SPECIES DIVERSITY, ABUNDANCE, AND DISEASE PREVALENCE OF CORAL REEFS IN KARIMUNJAWA, INDONESIA

Karimunjawa National Park (KNP) has increasing tourist visits and shipping traffic as its main tourist destination. These conditions have the potential to the degradation of coral reef ecosystems. Hence, the objective of this study was to investigate the biological effects of anchorage on disease prevalence, % coral cover, abundance, and diversity of corals. The six islands with high, medium, and low anchoring intensities were selected. The survey method was carried out by scuba diving on each selected island at depths of 3 and 8m by establishing a 2x25m line and belt transects with three replications. The statistical results indicated that there were significant differences among anchoring levels in disease prevalence. Even the coral abundance and diversity tend to be lower on the island with high anchoring activity. However, there were no significant differences in species richness, diversity index, or relative abundance among anchoring levels. Moreover, the different levels of anchoring also made no difference in the percentage of coral cover (p 0.087 >0.05). This study revealed that anchoring damage might be indirectly responsible for the dispersal and elevated levels of disease. Further study is needed to identify anchoring activity and coral disease in wider areas to conserve the coral reefs of KNP.