Coral Condition Research Articles

Coral reef condition Kepala Jeri Island, Batam, Riau Islands, Indonesia

Abstract. Aunurrahman, Anggoro S, Saputra SW, Muskananfola MR. 2024. Coral reef condition Kepala Jeri Island, Batam, Riau Islands, Indonesia. Biodiversitas 25: 2820-2827. Understanding the actual condition of vulnerable coral reef ecosystems such as Kepala Jeri Island (Indonesia) is critical to enabling appropriate management planning. This research aimed to identify current coverage, observe the condition of the coral ecosystem, and identify the species composition of coral reefs in Kepala Jeri Waters. Data collection includes the spatial distribution, actual condition, and species composition of the coral ecosystem on Kepala Jeri Island, Riau Islands, Indonesia. Using an algorithm-based classification, we analyzed the spatial distribution of coral reefs from Landsat 8 OLI imagery. The study used Landsat OLI 8 images from the US Geological Survey (USGS) and observed the data using a line intercept transect. We obtained the actual coral conditions and species composition through field observation. The results revealed a total distribution of 239.67 ha of coral reef ecosystem in the surrounding area of Kepala Jeri Island. Unfortunately, the coral reef on Kepala Jeri Island was in poor condition, with an approximate living coral coverage of only 5-29.33%. Compared to other locations, we found the sand cover to be the highest, ranging from 28.33 to 51.67%. We also found that the seagrass bed had invaded the coral ecosystem, suggesting a reduced or absent population of halos grazers. Only the western and northern sides of Kepala Jeri Island exhibit adequate coral diversity despite discovering 26 coral species. Even though 26 coral species were found on Kepala Jeri Island, only the western and northern sides have adequate coral diversity. The findings suggest that the coral reef ecosystem on Kepala Jeri Island is under severe degradation, while the risk of further degradation remains. Therefore, human intervention is absolutely important to improve the coral reef ecosystem on Kepala Jeri Island, ensuring its sustainability.

Implications of fisher perceptions on coral restoration in Tondol, northwestern Philippines

Increasing coral restoration efforts globally have been aimed at improving reef status and the ecosystem functions and services they provide, including enhancing reef fish communities and fisheries production on nearby reefs. However, empirical evidence showing the influence of coral restoration on fish stocks is limited. In Barangay Tondol, a small-scale fishing village in the northwestern Philippines, fisher knowledge and perception studies were completed through individual interviews to provide insights into the perceived impacts of local restoration efforts on coral reef conditions and fishery outputs. The influence of fishers' social demographics and fishery information to their held perceptions were also explored. Fishers’ responses showed a perceived decline in fish stocks over the last 5–10 years mainly attributed to overharvesting, and a slight improvement in coral reef condition due to a reduction in destructive fishing. Out of 53 fisher respondents, 72% were aware of coral restoration efforts in their area and held positive perceptions that theoretically, conducting coral restoration can improve their fish stocks and local reef conditions through the provision of habitat functions. Perceived actual effectiveness of the local efforts was also positive, but with a lower number of responses. Multiple hierarchical regression tests showed that, among social demographics, fishery information, and perceptions on fish stocks, perceived improvement in coral condition was associated with stronger support for coral restoration activities. These findings indicate that fishers perceive positive effects of coral restoration to local coral status and fisheries, and highlight the need for restoration practitioners to engage early on with key stakeholders to assess local fisheries status and local priorities to inform restoration strategies.

Christmas tree worm Spirobranchus spp. (Annelida: Serpulidae) as indicators of coral health at Weh Island, Aceh Province, Indonesia

Abstract. Afkar, Barus TA, John AH, Sarong MA. 2024. Christmas tree worm Spirobranchus spp. (Annelida: Serpulidae) as indicators of coral health at Weh Island, Aceh Province, Indonesia. Biodiversitas 25: 1743-1753. The research was conducted along 300-m long transects at 3 and 7 m depth in Beurawang Waters, Weh Island, Aceh Province, Indonesia, which aimed to analyze the association of christmas tree worms (Polychaeta: Serpulidae: Spirobranchus) with coral health conditions and determine the impact of their presence on the coral reef ecosystem. On average, Spirobranchus individuals were more commonly found at 3 m than at 7 m depth. Spirobranchus was found to be most associated with massive corals of the genus Porites. Spirobranchus tends to be most abundant in damaged coral reef colonies, which suggests that coral conditions could worsen if the abundance of Spirobranchus worms increases. Statistical analysis also shows an association between the abundance of Spirobranchus and the condition of coral reefs, with a 'strong' relationship value of 0.611. Therefore, it is necessary to consider coral transplantation as an effort to repair damaged coral substrates in Beurawang Waters.

A quantitative assessment of the status of benthic communities on US Atlantic coral reefs using a novel standardized approach

As coral reefs decline globally, the need for an objective approach to quantify the status and trends of corals has become increasingly important. Empirical data on predisturbance conditions are rare, and integrating data from multiple and disparate survey designs and methods can be analytically challenging. Our goal was to conduct a holistic, data-driven evaluation of the status of corals and benthic communities in US Atlantic coral reef jurisdictions: Florida, Flower Garden Banks, Puerto Rico, and the US Virgin Islands. A quantitative approach based upon standardized data was used to compare the change in multiple indicators of coral condition (hard coral, macroalgae, and crustose coralline algae cover, coral density, and old mortality) from historic to current conditions in each geographic region. For each indicator, historic, reference baseline conditions from long-term monitoring data or literature data were first identified, reviewed, and classified on a categorical scale from Very Good to Critical by regional experts to account for condition changes that pre-dated current monitoring data. A reference-centering approach then allowed for categorization of statistical changes from historic to current conditions on the same scale to produce results that could be communicated to a broad audience. Our findings show continued declines for multiple indicators in all regions except Flower Garden Banks, illustrate particularly dire declines from regions that had been impacted by Stony Coral Tissue Loss Disease at the most recent monitoring included in this study, and demonstrate the increasingly critical need for effective coral reef conservation.

Analysis of the Rate and Nutrient Content of Sediment in The Coral Transplantation Installation Vertical Method on Samalona Island, Makassar City

Samalona Island is a small island that administratively belongs to the inner zone of the Spermonde Islands region with low live coral cover. One effort to improve coral conditions is to carry out vertical transplantation, but hydro-oceanographic conditions are thought to be an inhibiting factor, including sediment. The research carried out aims to determine the suitability of oceanographic parameters, estimate sediment rates, and determine the phosphate and nitrate in sediments. The research method used a field experiment method by taking water and sediment samples and installing sediment traps for 15 days. The parameters measured in situ are temperature, pH, current speed, salinity, and dissolved oxygen, while the ex-situ test is the dry weight of sediment, TSS, nitrate, and phosphate concentrations. Data analysis uses descriptive statistics and is categorized according to the evaluation instrument used. The research results show that the values for temperature, pH, current speed, salinity, and dissolved oxygen meet the standard criteria for coral-based on PP 21/2022. The sediment rate during the research period was 0,003 – 0,015 gr/cm2/day, so it was categorized as having the potential damage to corals with a mild to severe impact level. The nitrate concentration in sediment ranges from 0,19 – 0,25 ppm while phosphate ranges from 0,35 – 0,72 ppm, so it can be said to be waters with a medium trophic level (mesotrophic). The current speeds and sediment rates potentially accelerate nutrient concentrations and cause sediment resuspension, thereby closing coral polyps, especially on corals closest to the substrate where vertical coral transplant installations are installed.

Epizoic yellow sponge (Poecilosclerida, Demospongiae) expansion on living Scleractinian corals in Bintan, Riau Archipelago, Indonesia

AbstractCoral reef ecosystems in Indonesia are under threat due to changes in the environment driven by global climate change, along with local disturbances such as sedimentation and eutrophication. Consequently, comprehensive coral reef monitoring activities have been initiated at numerous locations across Indonesia. In this study, the findings from coral reef health surveys across 14 reef sites (within 40 hectares) in the Bintan area (Riau Archipelago, Indonesia; 100 km southeast of Singapore) revealed a potentially novel epizoic yellow sponge species (Phorbas sp.) that overgrows coral colonies. This species, tentatively classified as a new Phorbas sp. (order Poecilosclerida: family Hymedesmiidae), was identified through a combined approach employing classical taxonomic methods along with DNA barcoding using the cytochrome c oxidase I (COI) gene. At every site, three permanent 20‐m transects were established to annually monitor live coral coverage and species composition between 2014 and 2017. The survey indicated a notable change in the overall coral cover during this period. The abundance of coral diseases was investigated in 2014 and 2017. Additionally, the progress of Phorbas sp., was closely monitored (i.e., every second day for one week) at Bintan Island (site 11) during the dry season in August 2017. This approach aimed to approximate the relative impact of each incident on the coral's condition. The results indicated that the most comprehensive change occurred due to the overgrowth of Phorbas sp., which affected 12 scleractinian coral species across eight genera in almost all sites except one. The abundance of this epizoic sponge infestation was highest at Pulau Beralas Pasir (site 10), constituting 22.9% of all recorded life forms, and lowest at Pulau Pangkil‐Besar (site 13), with only 0.7%. The expansion of the thin yellow sponge tissue was estimated to increase by up to 0.51 ± 0.48 cm2 per day on Porites coral.

Coral health assessment of two marine national parks (takabonerate and wakatobi) in southern sulawesi

Coral reef ecosystems carry out a wide range of ecological functions and sustain the livelihoods of coastal communities through fisheries, coastal protection, and tourism. However, the coral condition has declined recently due to climate changes and anthropogenic activities. This study was undertaken in May 2019 to assess reef health status in Takabonerate and Wakatobi Marine National Park based on three components: live coral cover, resilience component (macroalgae and rubble cover), and fish biomass. The highest coral cover was 45.53% (Wanci), with an average cover of 24.6% and 29.48% in Takabonerate and Wakatobi. The average biomass of reef fish in Wakatobi was higher in Wakatobi (1.26 kg/ha) than in Takabonerate (0.70 kg/ha). For the resilience score, the average cover of macroalgae and rubble was 0.11% and 6.35% in Takabonerate and 1.64% and 0.51% in Wakatobi. Based on the coral, resilience, and biomass fish score, the Coral Health Index scored 5 (fair) and 9 (good) for Takabonerate and Wakatobi. The data suggested that reefs in both locations could recover from disturbance. However, the low biomass of targeted fish in the Takabonerate shows high fishing activities, which might lead to a direct/indirect impact on coral health.

Potential of antagonistic activity from associated bacteria from healthy and bleaching acropora corals of Blitar Waters, East Java, Indonesia

Global warming leads to high coral bleaching phenomena in marine ecosystems. The bleach condition of corals can cause a disease that is enhanced by opportunistic or pathogenic microorganisms. This research aimed to investigate the antagonistic interactions between healthy and bleached coral-associated bacteria. Isolation of coral-associated bacteria was carried out using the spread plate method in half-strength Zobell 2216E medium. Antagonistic activity was observed using a double-layer method, with each layer of medium inoculated with healthy or bleached coral-associated bacteria. The interactions between healthy and bleached coral isolates were analyzed using correspondence analysis. Twenty healthy and 11 bleached coral isolates were found in the six coral samples. Approximately 14 bacterial isolates from healthy corals demonstrated antagonistic (inhibitory) activity against 11 bacterial isolates from bleaching coral samples, with isolate AcD.14 from bleached coral, inhibited by 57.14% of the active isolates from healthy corals. Correspondence analysis resulted in isolate AcD.16, a bleaching coral bacterium with sufficient pathogenicity to elicit an antagonistic response from healthy coral bacteria. This study showed that there is high potential for finding bio-control agents for coral diseases using their natural microbiomes from healthy corals.

Condition of Coral Reef in Kelagian Besar Island

The coral reef ecosystem plays many important roles for society. One of the its role is as a tourist attraction. Kelagian Island lies near Pahawang island which is the major attraction of marine tourism in Lampung. This position makes Kelagian Island the most potential alternative island after Pahawang Island. However, sufficient information about the coral condition and profile in Kelagian Island has yet to support this potential. For that reason, a study about coral reef conditions on Kelagian island must be conducted to provide information and support the possibility of tourism development on Kelagian island. This study was conducted in August 2022 using Point Intercept Transect (PIT) in three different sites on Kelagian Island. Coral reef condition in 3 meter depth were generally in good condition, meanwhile in 7 meters depth coral reef condition were in medium state. There were 22 genera found in Kelagian island. Acropora and Porites were found dominating three meter depth. On the other hand in seven meter of depth, Goniopora and Favia were abundantly found. Diversity index, Evenness, and Dominance Index in Kelagian Island are 2,29-2,49 (medium), 1-0,83 (stable), and 0,12-0,15 (low) respectively.

Characteristic of Microplastic on Coral Reef Sediment and Sea Urchin (Diadema sp.) in Tidung Island, Jakarta Bay, Indonesia

Microplastics are recognized as common contaminants of coral ecosystem in Tidung Island, affecting both sediment and sea urchins residing in this environment. Therefore, this study aimed to determine the characteristics of microplastics found in sediment, the mouth, and the digestive system of sea urchins (Diadema sp.), assessing the relationship between coral cover percentage and microplastic type and size, and the transfer of microplastics from sediment to sea urchins. Sampling was conducted twice, namely in October 2021 and October 2022. Microplastics in sediments were extracted using ZnCl2. The destruction process of sea urchins used 30% H2O2 and FeSO4.7H2O, while the microplastics were identified with Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR). The results showed that the microplastics found in the sediments and sea urchins were similar in terms of shape, color, size, and plastic polymers. The forms of microplastics found in this study were fibre, fragment, and foam with fibre predominance, based on the results obtained. The size of microplastics found in sediments and sea urchins was dominated by sizes >1000 µm. Fibres were found in hard coral (HC) and dead coral (DC) conditions while fragments and foams were present in turf algae (TA), sponge (SP), and soft coral (SC) conditions. The microplastics found in sea urchins originate in part from sediments because they have similar characteristics. Sea urchins ingested microplastics from sediment, particularly those grown by algae as a food source. The increase in the number of microplastics found in sediment could potentially result in higher abundance in the biota.

The biological and ecological impact of the ship grounding and ore nickel spill of the barge ship in Morowali Waters, Central Sulawesi, Indonesia

This study’s purpose is to know the condition of corals in locations that are under pressure due to high sedimentation and coral damage due to ship aground. The research was carried out in August 2021 by collecting data related to the coral reef’s condition. The method used the Underwater Photo Transect (UPT) at 2 location points as controls which were assumed not to be affected by the ship aground and 2 location points where the ship ran aground. The study was successful to obtain data on the affected corals on the BG Financia 22 ship at 13.13%, while at the control location, live coral cover was obtained by 17.16%, grouped in very damaged condition. Observations on the BG Intan Kelana 3 ship from a total observation area of 127,600 cm2, obtained a live coral cover of 24.70%, this condition is grouped in very damaged coral conditions. Types of coral were found in 17 genera from 247 colonies observed during the study. Coverage at affected locations is 4.20%. Observations in this study can be concluded at the location where the condition of the coral is very damaged plus the pressure due to the ship aground, thus worsening conditions in the area.

PLANNING ANALYSIS OF KALEDUPA PORT WHARF BY USING SAP2000 SOFTWARE

Kaledupa Port is a public port that serves a limited number of domestic sea transportation activities. With the growth of the tourism sector in Wakatobi Regency, especially at Kaledupa Island, the operational intensity of the Kaledupa port has also continued to increase. One of the efforts that can be made in the development of Kaledupa Port is to analyze the planning of the Kaledupa Port wharf for quality improvement and evaluation at the Kaledupa Port. This study aims to find out what kind of loads work on the wharf which can then be modeled for wharf planning in the SAP2000 software. Based on the planning analysis, the Kaledupa port wharf is planned to have a length of 82 m and a width of 10 m with a general cargo ship with a maximum weight of 1,000 DWT. The results of the wharf modeling in the SAP2000 software with steel piles with a diameter of 508 mm and a thickness of 14 mm with a carrying capacity is 86.31 tons and based on the carrying capacity of the soil at location BH-02 the soil carrying capacity is 158.88 tons at a depth of 23 m with hard soil or coral conditions.

Hierarchical drivers of cryptic biodiversity on coral reefs

AbstractDeclines in habitat structural complexity have marked ecological outcomes, as currently observed in many of the world's ecosystems. Coral reefs have provided a model for such changes in marine ecosystems; still our understanding has been centered on corals and fishes at broad spatial scales when metazoan diversity on coral reefs is dominated by small cryptic taxa (herein: “cryptofauna”). Given the paucity of studies and high taxonomic complexity of the cryptofauna, both of which limit a priori hypotheses, we asked whether hierarchical structuring theory provides a compelling framework to impose order and quantify patterns. In general terms, we explored whether cryptic communities are sufficiently described by broad seascape parameters or limited by a set of processes operating at their distinctly nested microhabitat scale. To address this theory and gaps in knowledge for the cryptofauna, we characterized community structure in coral rubble, an eroded coral condition where biodiversity proliferates. Rubble was sampled along a depth and exposure gradient at Heron Island on the Great Barrier Reef, Australia, to parameterize environmental and morphological indicators of sessile taxa and motile cryptofauna communities. We used a hierarchical study framework from microhabitat to seascape scales, which were evaluated using nonstructured multivariate analyses and Bayesian structural equation modeling. While the nonstructured analyses showed the effects of seascape on the cryptobenthos and its community, this approach overlooked the finer hierarchical patterns in rubble ecology revealed only in the structured model. Seascape parameters (exposure and depth) influenced microhabitat complexity (i.e., rubble branchiness), which determined the cover of sessile organisms on rubble pieces, which shaped the motile cryptofauna community. Rubble is likely to be increasingly prevalent on coral reefs in the Anthropocene and is typically associated with low seascape‐level complexity and reduced macrofaunal richness. Parallel with hierarchical structuring theory, we showed a similar response operating at the microhabitat scale whereby low rubble complexity (i.e., branchiness) reduced cryptobenthic structure, diversity and size spectra. In a future ocean, we expect there may be an initial increase in biodiversity and trophodynamic processes derived from branching rubble, but a delay in ecosystem‐scale outcomes if coral, and thus rubble, generation and complexity is not sustained.

Coral resistance in coral bleaching events in Lombok waters, Indonesia

The western area of Lombok Island is a tourist area that has rich underwater biodiversity in coral reefs ecosystem because of the flow path of Indonesia Trough Flow which carries nutrients continuously through the Lombok Strait. Damage that occurs around the Western area of Lombok Island is caused by climate change and community waste disposal activities that cause coral bleaching. An increase of 1.23°C Sea Surface Temperature occurred in Sekotong on February 2016 and leads to the coral bleaching event on the area. The research was conducted by using the underwater photo transect method and the photos processed by CPCe program shows mass coral bleaching impacted coral condition in West Lombok. Live coral cover was decreased 2.74% comparing with last live coral cover. Total colonies were impacted by coral bleaching 40.04% in Gili Tangkong and 43.63% in Gili Asahan. This Study shows that each species survives and be able to be broodstock for the next life of corals in these areas.

Health Condition of Hard Corals on Rote Island in The Sawu National Park Conservation Area

Rote Ndao waters are known as a source of diversity of coral reefs in TNP Laut Sawu. Coral reefs in the area suffered considerable damage due to human activities. This study aims to determine the latest health conditions of the coral reef area in the northern region of Rote Island. Data monitoring was carried out using the underwater photo transect (UPT) method at 12 stations in the north of Rote Island. The percentage of coral reef bottom substrate cover was obtained by processing photo data using the Coral Point Count with Excel Extension-CPCe application. In addition, an assessment of the benthic component was also carried out based on the categories of percentage cover of fleshy seaweed, cover of rubble and hard coral. The results show condition of coral reefs based on percent cover is in the low category with a hard coral (HC) value of 9.02 ± 7.16%. The highest average value of hard coral cover was found at the Tesabela station. The three highest mean values for the bottom substrate cover type at the observation sites were dead coral with algae (DCA) 32.91 ± 19.5%; Algae assemblage (FS) 17.50 ± 19.27% and Sand (S) 17.43 ± 8.91%. The health condition of coral reefs based on the benthic component shows that the coral reef ecosystem is in a damaged condition and it is difficult to recover if it is disturbed. Necessary to carry out good and efficient management in the future, namely by reducing human activities without causing damage to coral reefs and finding ways for the community to continue to benefit economically from coral reef areas in the Sewu Marine National Park.

Photo-physiology of healthy-looking and diseased/health-compromised hard corals from Mauritius Island, Western Indian Ocean

Abstract. Jogee SY, Jeetun S, Ricot M, Taleb-Hossenkhan N, Mattan-Moorgawa S, Kaullysing D, Riemann P, Blanc L, Casareto BE, Suzuki Y, Bhagooli R. 2023. Photo-physiology of healthy-looking and diseased/health-compromised hard corals from Mauritius Island, Western Indian Ocean. Indo Pac J Ocean Life 7: 27-37. The spatial photo-physiological responses of in hospite zooxanthellae in hard corals, including coenosarc and polyps, healthy-looking and affected parts in four coral diseases, namely Brown Band, Black Band, Skeletal Eroding Band and White Band on the coral Acropora muricata, and two health-compromised conditions such as the Pink Pigmentation Response and its differentiated morphology, the Pink Line Syndrome, on the coral Porites were investigated using the Imaging-PAM fluorometry. A significantly lower Fv/Fm was observed in case of Black Band, White Band, Brown Band and Pink Pigmentation Response affected parts compared to the healthy-looking parts. The Fv/Fm had the highest decline in Brown Band disease. Both the polyps and coenosarc had significantly lower Fv/Fm in White Band and Brown Band diseased parts compared to their healthy-looking parts. The rETRmax did not change significantly between diseased/health-comprised parts and healthy-looking parts. NPQmax declined significantly in White Band, Black Band and Pink Pigmentation Response cases. ? and ? generally did not tend to be affected in diseased/health-compromised conditions. The photo-physiology of in hospite zooxanthellae was least affected in Pink Line Syndrome. These findings suggest that diseased/health-compromised parts of corals behave differently in terms of their photo-physiology in different diseased and health-compromised coral conditions in important reef-building corals species such as A. muricata and Porites species, with important implications for the productivity and thus adaptive management of coral reefs in a globally warming ocean.

Is the variability of butterflyfish species domination driven by its habitat conditions?

The coral conditions contribute to the abundance and species composition of butterflyfish. This study investigates the relationship between its habitat conditions and dominance of butterflyfish in western Indonesia. Data were collected using UVC in 78 sites during 2015, 2016, and 2018 that are grouped into 2 groups. The results show group A has a lower number of species (2 - 6) but the density is high, instead, group B is 9-20 species but has a low density. Species dominant and their relations with benthic substrate were Chaetodon octofasciatus (7.2%) in group A, and group B Heniochus pleurotaenia and Chaetodon triangulum (21%). The differences in species domination might also be affected by habitat conditions, such as the period of the highest sea surface temperature. The group had different environmental conditions, which group A might be influenced by the Karimata strait and Indian Ocean west Sumatera in group B. Those 4 species have relation to SST include F. flavissimus.

Biodiversity and Aquatic Vegetation Succession in Biawak Island Marine Protected Area, Indramayu-West Java

The existence of aquatic vegetation in the coastal waters is correlated with the water quality parameters. Seagrass and macroalgae are aquatic plants often found to form a coastal ecosystem that depends on water quality, both physically and chemically. Research on the existence of aquatic plants in Biawak Island, Indramayu, West Java, was conducted in 2016 and 2019 by combining in situ data and secondary data. The purpose of this study was to observe the dynamics of seagrass ecosystems as aquatic plants on Biawak Island and their correlation with the succession that occurred in the aquatic environment in Biawak Island as part of the Biawak Archipelago Marine Protected Area (MPA). The research method integrates a descriptive analysis and its correlation between the submerged aquatic plants and their environment. The results showed that seagrasses in Biawak Island tend to disappear and be replaced by macroalgae. The type of seagrass found in 2016 was Enhalus Acoroides covered by epiphytes perished in 2019. The abundance of macroalgae, especially Halimeda macroloba, indicates the existence of nutrient enrichment and high turbidity, causing the seagrass to be replaced by macroalgae. Another biodiversity found in the region was clams and sea cucumber, while branching coral conditions experienced bleaching and degradation. An environmental condition contains high nutrients strengthening the nutrient enrichment for a particular time. Therefore, integrated management regarding terrestrial and shipping lines track needs to be addressed to maintain the sustainability of the natural resources in the Biawak archipelago.

Photo-physiology of healthy and bleached corals from the Mascarene Plateau

This study presents the first report of variable photo-physiology of healthy-looking and bleached corals from the upper mesophotic waters of the Mascarene Plateau. In May 2018, during the FAO EAF-Nansen research expedition cruise, coral bleaching was visually observed. Five coral species from Saya de Malha Bank, namely Heliopora coerulea, Favites sp. and Porites sp. from 27 m and Acropora sp. and Lithophyllon repanda from 30 m, and three coral species from the Nazareth Bank, namely Acropora sp. and Galaxea fascicularis from 36 m and Stylophora-like species from 58 m were studied using the Video-Assisted Multi-Sampler (VAMS) and collected using a Van Veen grab. Chlorophyll a fluorescence parameters such as effective quantum yield at photosystem II (ΦPSII), relative maximum electron transport rate (rETRm), photosynthetic efficiency (α), photoinhibition (β), saturating light level (Ek), and maximum non-photochemical quenching (NPQm) were measured using a Diving-Pulse-Amplitude-Modulated (D-PAM) fluorometer to study variable photo-physiology in bleached and non-bleached corals. All photo-physiological parameters varied significantly among coral species tested and between coral conditions, except for β. The interaction between species and coral conditions was only significant in the case of β, but generally not significant. A two-way ANOVA indicated significant effects of depth and coral conditions in Acropora sp. on almost all photo-physiological parameters, except for β, and the effect of depth on rETRmax and α, and the effect of depth along with its interaction with coral conditions on Ek. ΦPSII did not differ in bleached and healthy-looking coral parts of Porites and Lithophyllon from 27 m, Galaxea and Acropora from 36 m while it decreased significantly in Heliopora and Favites at 27 m, Acropora from 30 m, and Stylophora-like at 58 m. NPQm did not change for Porites, Acropora (30 m) and Galaxea but it tended to increase for Heliopora, Acropora (36 m), Lithophyllon, Galaxea, and decrease for Favities, Acropora (30 m) and Stylophora-like. The thermally tolerant coral Porites exhibited normal photo-physiology even in bleached conditions while the bleached parts of Favites, Acropora (30 m) and Stylophora-like corals exhibited photo-physiological dysfunctioning. This study revealed that the seven studied corals from the upper mesophotic waters of the Mascarene Plateau are not spared from the bleaching phenomenon and exhibit variable photo-physiology in bleached and non-bleached conditions. Further studies are warranted to thoroughly understand the coral bleaching patterns and severity during summer periods at the Saya de Malha and Nazareth Banks.

Coral Reef Conditions At the Snorkeling Spots of the Karimunjawa National Park, Indonesia

Abstract Karimunjawa as a marine national park has attracted tourists to come and explore coral reefs. The reefs are under increasing pressure from the development of underwater tourist activities so it is necessary to pay attention to the reef condition to maintain its sustainability. This study was conducted in September 2019 by examining the condition of coral reefs in the most visited snorkeling spots based on information from tour operators, i.e. the Ujung Bintang, Maer and Karang Sendok spots. Data was collected using a 20 m line belt transect to count coral cover and was analyzed using coral morphology triangles to assess the Coral Condition Index (CCI) and Impact Severity Index (ISI). The condition of coral reef cover at the Ujung Bintang and Maer spots were in the “good” category based on the CCI, while at the Karang Sendok spot the corals were in the “bad” category based on the ISI. The three snorkeling spots have competition-adapted (K) morphology, which means that the coral reefs are dominated by non-Acropora corals associated with coral reefs with high waves. The dominant life form at the Ujung Bintang spot was foliose corals, at the Maer spot, it was foliose coral and non-Acropora branching corals, while at the Karang Sendok it was Acropora, which is more vulnerable than foliose and massive corals. The CCI at the three spots was in the “good” category as there are healthy coral colonies, whereas the ISI was in the “poor” category since partially and recently dead coral colonies were found there. The coral colony damage in the spots was dominated by bleached coral colonies and partially dead coral colonies.