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1
Putra, Singgih A., Helmy Akbar, and Indra A. Syari. "Shallow-water hard corals (Hexacorallia: Scleractinia) from Bangka Belitung Islands Waters, Indonesia." Aceh Journal of Animal Science 4, no. 2 (October 31, 2019): 89–98. http://dx.doi.org/10.13170/ajas.4.2.14571.
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Bangka Belitung Islands (Sumatra, Indonesia) has various coastal resources, e.g., coral reefs, seagrass beds, mangrove forests. However, the coral community has been threatened by anthropogenic activities, i.e., tin mining and illegal tin mining. Threatened species assessment is important for mitigation of coral losses and management. The ojective of the present study was to examine the status of Scleractinian corals in Bangka Belitung Islands, Indonesia. A line intercept transect was performed for the coral reef survey. Live and dead coral cover were recorded in the three locations. Corals species were identified following taxonomic revisions. The results showed that there were 142 species of Scleractinian corals recorded from Bangka Belitung Islands. Of these, 22 species are the new report from the areas of the the eastern part of Belitung Island. Family of Merulinidae, Acroporidae, and Poritidae were predominant group in this region. It is concluded that the condition of the coral reef ecosystem in the Belitung Islands is relatively good, but fair in Gaspar Strait and Bangka Island. Keywords: Coral cover, coral diversity, hard coral, Scleractinia
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Briggs, Amy A., Anya L. Brown, and Craig W. Osenberg. "Local versus site-level effects of algae on coral microbial communities." Royal Society Open Science 8, no. 9 (September 2021): 210035. http://dx.doi.org/10.1098/rsos.210035.
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Microbes influence ecological processes, including the dynamics and health of macro-organisms and their interactions with other species. In coral reefs, microbes mediate negative effects of algae on corals when corals are in contact with algae. However, it is unknown whether these effects extend to larger spatial scales, such as at sites with high algal densities. We investigated how local algal contact and site-level macroalgal cover influenced coral microbial communities in a field study at two islands in French Polynesia, Mo'orea and Mangareva. At 5 sites at each island, we sampled prokaryotic microbial communities (microbiomes) associated with corals, macroalgae, turf algae and water, with coral samples taken from individuals that were isolated from or in contact with turf or macroalgae. Algal contact and macroalgal cover had antagonistic effects on coral microbiome alpha and beta diversity. Additionally, coral microbiomes shifted and became more similar to macroalgal microbiomes at sites with high macroalgal cover and with algal contact, although the microbial taxa that changed varied by island. Our results indicate that coral microbiomes can be affected by algae outside of the coral's immediate vicinity, and local- and site-level effects of algae can obscure each other's effects when both scales are not considered.
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Hoang, Phan Kim, Vo Si Tuan, Thai Minh Quang, Dao Tan Hoc, and Hua Thai Tuyen. "Bleaching of coral in Nha Trang, Ninh Thuan, Con Dao and Phu Quoc islands in June–July 2019." Tạp chí Khoa học và Công nghệ biển 20, no. 4A (April 11, 2021): 55–60. http://dx.doi.org/10.15625/1859-3097/15649.
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The studies on coral bleaching were conducted at 21 sites of 4 reef areas in Southern Vietnam, using point transect technique in June–July 2019. Cover of hard corals in the selected sites was quite high with the average values of 65.6 ± 18% % in Con Dao islands, 58.7 ± 26.2% in Ninh Thuan coastal waters, 55.9 ± 17.8% in Phu Quoc island but lower in Nha Trang bay (22.8 ± 15.9%). Soft corals were not abundant with the highest cover in Nha Trang bay (4.73 ± 5.5%) and the lowest in Ninh Thuan (0.16 ± 0.3%). Hard corals were most impacted in Nha Trang bay with 39.5 ± 8.1% bleached, followed by Ninh Thuan reefs (32.9 ± 13.3%), Con Dao Islands (25.0 ± 11.1%) and least affected in Phu Quoc island (7.3 ± 9.05%). For soft corals, ratios of bleached corals were 79.4%, 65.8% and 23.8% in Con Dao islands, Nha Trang bay and Ninh Thuan reefs respectively. No bleached soft coral was recorded in Phu Quoc. At the genus level, Acropora corals were severely affected in Nha Trang bay, Ninh Thuan reefs and Phu Quoc island but not impacted in Con Dao islands. The Porites, Montipora, Millepora genera were quite vulnerable in all sites but no bleaching was observed for Galaxea and Diploastrea genera.
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Moradi, Mahdi, Reza Malekzadeh-Viayeh, and Javad Eshaghi-Rad. "Biodiversity of scleractinian corals in the reefs of Qeshm and Larak Islands of the Persian Gulf, in association with environmental variables." Journal of the Marine Biological Association of the United Kingdom 94, no. 5 (April 8, 2014): 907–16. http://dx.doi.org/10.1017/s0025315414000411.
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Diversity of hard corals is investigated on the reefs of two Iranian islands, Qeshm and Larak, located in the Persian Gulf. The corals were sampled and photographed and their percentage cover was estimated by diving in June 2008 and February 2009. Thirty-eight coral species belonging to 20 genera and nine families were identified, of which three species are new records from the Gulf. Coral diversity was higher in Larak Island, and in total, Acroporidae and Faviidae were the most diverse coral families. Acropora (83%) had the highest percentage cover in Larak Island, while the maximum percentage cover in Qeshm Island was for Porites (52.96%). Canonical correspondence analysis distinctly plotted the study sites against environmental variables. Salinity and pH were the most effective variables on the coral diversity, and had positive correlations with the frequency of several species including Pocillopora damicornis, Platygyra acuta and Acanthastrea maxima, while they had negative correlation with another group of other corals, including Plesiastrea devantieri, Acropora downingi and Psammocora digitata (P < 0.01). Water clarity had positive correlations with some coral species, including Cyphastrea serailia and Coscinaraeamonile, and negative correlations with other species such as Leptastrea transversa and Acropora arabensis. Diversity of a number of corals mainly Porites lutea and Cyphastrea chalcidicum had high affinity with the water temperature. The results of this study supported the existence of diversified coral communities in Iranian islands, while showing that their spatial and temporal distribution can be affected by environmental variables.
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Ulfah, Maria, Saiful Mahlil, Muhammad Nasir, Sayyid Afdhal El Rahimi, Syahrul Purnawan, and Muhammad Rizki Fazillah. "Condition of coral reef in Batee Island waters, Peukan Bada Sub-District, Aceh Besar." Depik 10, no. 2 (June 16, 2021): 115–19. http://dx.doi.org/10.13170/depik.10.2.19995.
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Batee Island is one of the small islands in the Aceh Besar region and is uninhabited and directly faces the Indian Ocean. Batee Island's waters have the potential for marine biota, especially coral reef ecosystems, and other associated biotas. This study aims to determine the percentage and comparison of live coral cover in Batee Island waters and determine the genus' composition in Batee Island waters. This research was conducted in October-November 2016. Collecting coral reef data using the LIT (Line Intercept Transect) method. The results showed that the live coral cover in Batee Island's waters differed between the East and West Batee Islands. The coral reefs' average condition in Batee Island waters at shallow depths (0-5m) is 41.41%, and deep (6-10m) is 36.52%. Overall, the conditions and live coral cover in the waters of Batee Island are classified as moderate. In the waters of Batee Island, there are 31 coral genera. The highest percentage of corals was the genus Acropora (50.02%).Keywords:Batee IslandConditionCoral reefCoral cover
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Ferdiansyah, M. Husien, Endang Linirin Widiastuti, Teguh Ismail, and Gregorius Nugroho Susanto. "INVENTARIZATION OF CORAL REEFS IN THE WATERS OF RAKATA ISLAND, KRAKATAU ISLANDS." AQUASAINS 8, no. 1 (November 28, 2019): 775. http://dx.doi.org/10.23960/aqs.v8i1.p775-782.
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Abstrak Indonesia is an ideal place for coral growth because of the tropical climate. Rakata Island is included in the Krakatau Islands Nature Reserve and Marine Reserve area which is influenced by the volcanic activity of son of Krakatau Archipelago and human activities. Both of these activities will affect the growth of coral reefs. The purpose of this study was to determine the current condition of coral reefs and the diversity of living coral forms on Rakata Island. Collecting data for analysis of coral reef cover using the Line Intercept Transect (LIT) method was parallel to the coastline of Rakata Island at two points. The percentage of live coral cover from points I and II at a depth of 5 meters was 50.69% and 33.80% classified as in good and moderate conditions respectively. While the percentage of live coral cover at a depth of 10 meters at points I and II were 41.90 % and 16.01% whice were in moderate and poor conditions. The coral reefs mostly found in point I were leaf corals (CF) namely Turbinaria reniformis and Turbinaria frondens, while in point II were massive corals (CM) were found i.e. Goniastrea edwardsi, Favia pallida, Montastrea valenciennesi, Favites abdita, Astreopora listeria, and Favites complanata.
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Arulananthan, Ashani, Venura Herath, Sivashanthini Kuganathan, Anura Upasanta, and Akila Harishchandra. "The Status of the Coral Reefs of the Jaffna Peninsula (Northern Sri Lanka), with 36 Coral Species New to Sri Lanka Confirmed by DNA Bar-Coding." Oceans 2, no. 3 (July 26, 2021): 509–29. http://dx.doi.org/10.3390/oceans2030029.
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Sri Lanka, an island nation located off the southeast coast of the Indian sub-continent, has an unappreciated diversity of corals and other reef organisms. In particular, knowledge of the status of coral reefs in its northern region has been limited due to 30 years of civil war. From March 2017 to August 2018, we carried out baseline surveys at selected sites on the northern coastline of the Jaffna Peninsula and around the four largest islands in Palk Bay. The mean percentage cover of live coral was 49 ± 7.25% along the northern coast and 27 ± 5.3% on the islands. Bleaching events and intense fishing activities have most likely resulted in the occurrence of dead corals at most sites (coral mortality index > 0.33). However, all sites were characterised by high values of diversity (H’ ≥ 2.3) and evenness (E ≥ 0.8). The diversity index increased significantly with increasing coral cover on the northern coast but showed the opposite trend on the island sites. One hundred and thirteen species of scleractinian corals, representing 16 families and 39 genera, were recorded, as well as seven soft coral genera. Thirty-six of the scleractinian coral species were identified for the first time on the island of Sri Lanka. DNA barcoding using the mitochondrial cytochrome oxidase subunit I gene (COI) was employed to secure genetic confirmation of a few difficult-to-distinguish new records: Acropora aspera, Acropora digitifera, Acropora gemmifera, Montipora flabellata, and Echinopora gemmacea.
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Mukhopadhyay, Aju. "Story around the Wonderful World of Corals." IJOHMN (International Journal online of Humanities) 5, no. 2 (April 17, 2019): 15. http://dx.doi.org/10.24113/ijohmn.v5i2.96.
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Corals are special to our lives; they give us when alive as well as on their death. Corals are at the centre of biodiversity. Many solid elements allow us to stand, sit on or sleep on. Earth is the most common but we may rest on sand hill, mountain top or tree. Corals provide us the same solid base to stand on as earth when it dies. When it lives it gives shelter, protection and food to many living things. Coral reefs offer multiple benefits to people and the economy - providing food, sustaining livelihoods, supporting tourism, protecting coasts, and even helping to prevent diseases. India has many coral coasts and coral areas. Lakshadweep is the largest among them. The coral reef in and around Lakshadweep has fascinated us. A travel in the remote islands and visit among the corals was an unique experience. The article deals with all aspects of coral kingdom including the islands. Not only facts and figures, it tells the story of travel and more; what happened on the way and in between; adventurous from the beginning to the end.
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Nurdin, N., K. Amri, A. R. Rasyid, D. A. T. Pulubuhu, N. Nurdin, and T. Komatsu. "CORAL REEFS ON INHABITED AND UNINHABITED SMALL ISLANDS, SPERMONDE ARCHIPELAGO, INDONESIA." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B3-2021 (June 29, 2021): 609–16. http://dx.doi.org/10.5194/isprs-archives-xliii-b3-2021-609-2021.
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Abstract. The small islands in Indonesia is providing important ecosystem services. It is important to identify damages of a coral reef ecosystem and whether natural factors or anthropogenic factors are the main causes. Landsat images obtained with different sensors were analyzed for mapping coral reef on inhabited and uninhabited small islands, Spermonde archipelago, Indonesia. Overall accuracies of three habitats classification were 89.2% and 85.6%, respectively. They are live coral, dead coral and non-coral. Ground truth surveys were selected by using the unsupervised classification method The live coral in inhabited islands was slightly greater than in uninhabited. An increasing area of live coral was about 5.3 ha of the total area in 1990 per year while a decreasing of dead coral was 3.5 ha per year in inhabited islands. In uninhabited island, a decreasing speed of live coral habitat area was about 0.6 per year. During 29 years, a significant increase in the dead coral and decrease in live corals. It has been identified that the significant controlling factor for the disturbances in reef ecosystem is derived from natural and anthropogenic.
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Denley, Danielle, Anna Metaxas, and Robert Scheibling. "Subregional variation in cover and diversity of hard coral (Scleractinia) in the Western Province, Solomon Islands following an unprecedented global bleaching event." PLOS ONE 15, no. 11 (November 11, 2020): e0242153. http://dx.doi.org/10.1371/journal.pone.0242153.
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Coral reefs are critically important marine ecosystems that are threatened worldwide by cumulative impacts of global climate change and local stressors. The Solomon Islands comprise the southwestern boundary of the Coral Triangle, the global center of coral diversity located in the Indo-Pacific, and represent a bright spot of comparatively healthy coral reef ecosystems. However, reports on the status of coral reefs in the Solomon Islands are based on monitoring conducted at 5 stations in 2003–2004 and 2006–2007, with no information on how corals in this region have responded to more recent global bleaching events and other local stressors. In this study, we compare reef condition (substrate composition) and function (taxonomic and morphological diversity of hard corals) among 15 reefs surveyed in the Western Province, Solomon Islands that span a range of local disturbance and conservation histories. Overall, we found high cover of live hard coral (15–64%) and diverse coral assemblages despite an unprecedented 36-month global bleaching event in the three years leading up to our surveys in 2018. However, there was significant variation in coral cover and diversity across the 15 reefs surveyed, suggesting that impacts of global disturbance events are moderated at smaller scales by local anthropogenic factors (fisheries extraction, land-use impacts, marine management) and environmental (hydrodynamics) conditions. Our study provides evidence that relatively healthy reefs persist at some locations in the Solomon Islands and that local stewardship practices have the potential to impact reef condition at subregional scales. As coral reef conservation becomes increasingly urgent in the face of escalating cumulative threats, prioritising sites for management efforts is critical. Based on our findings and the high dependency of Solomon Islanders on coral reef ecosystem services, we advocate that the Western Province, Solomon Islands be considered of high conservation priority.
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Siringoringo, Rikoh Manogar, and Tri Aryono Hadi. "THE CONDITION OF CORAL REEFS IN WEST BANGKA WATER." Marine Research in Indonesia 39, no. 2 (November 19, 2015): 63–71. http://dx.doi.org/10.14203/mri.v39i2.86.
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Bangka Island is well known as the world’s largest tin producer. The inland and offshore tin mining has profound effects on the coastal environment, resulting in the high sedimentation in the water. Many corals suffered physiological damage due to low light intensity. The distribution of stony corals and the status of coral reefs was surveyed at 6 sites in West Bangka waters in October 2012. A total of 72 species of corals belonging to 33 genera and 12 families were found, and 4 species were distributed at all research sites. The live coral coverage was 36% on average and was categorized as being in fair condition. The coverage was 0% at Kamboja Island where the corals were the most affected by tin mining. The sediment flowed out from tin mining, blocked the light, and settled on the corals’ surface. Consequently, many corals were buried and the live corals decreased. It is obviously necessary to reduce and control the tin mining.
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Utama, Rizkie Satriya, and Agus Budiyanto. "Kondisi dan Keanekagaragaman Karang Batu di Perairan Sabang." Oseanologi dan Limnologi di Indonesia 2, no. 1 (May 5, 2017): 69. http://dx.doi.org/10.14203/oldi.2017.v2i1.25.
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<strong>Condition and Diversity of Stony Corals in Sabang Waters.</strong> Globally, coral reefs are facing a variety of threats, both natural and human activities. Coral reefs in the waters of Sabang in 2004 were hit by a tsunami and in 2010 an increase in sea surface temperatures caused a bleaching. These resulted in mass mortality of stony corals. This study aims to determine the current condition and the diversity of stony corals in Sabang waters. The study was conducted in May 2015 in ten stations spread over four islands, namely Pulau Weh, Pulau Rondo, Pulau Breueh, and Pulau Nasi Besar. The coral cover is calculated using Underwater Photo Transect (UPT) method. The images were analyzed using CPCe 4.1 program with 30 random points in each frame. The number of species and the number of coral colonies are calculated based on the number of species and coral colonies contained in the photo frames along the transect. Based on the results of the analysis, live coral cover ranged 22.45–58.60% with an average live coral cover of 41.99%. Throughout the transect, 148 species of stony corals from 37 genera and 15 families were discovered. In general, stony corals in Sabang waters are in a good condition, not different from the condition of coral reefs in 2005. Open waters have a positive impact on coral growth, especially for the genus Acropora.
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Acosta, Charles A., and Mark J. Butler IV. "Role of mangrove habitat as a nursery for juvenile spiny lobster, Panulirus argus, in Belize." Marine and Freshwater Research 48, no. 8 (1997): 721. http://dx.doi.org/10.1071/mf96105.
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The use of mangrove prop roots and associated coralline habitats by Caribbean spiny lobsters was investigated near two types of mangrove islands in Belize. Spiny lobsters sheltered among mangrove prop roots, in undercut peat banks and under corals near islands, and they ranged in size from newly recruited juveniles to subadults. Lobsters preferred to shelter under large stony corals, but their use of mangrove prop roots nd undercut peat banks increased when the density of corals was low. Den residence time and distance moved within a site were similar at islands isolated by deep water channels and islands separated by shallow seagrass beds, but as a consequence of high immigration rates, population sizes were highest near shallow islands. Predation on newly settled juveniles was greater in seagrass and coral crevices than in mangrove prop roots, whereas the survival of larger juveniles was higher in mangroves and coral patch reefs than in seagrass. These results suggest that mangrove habitats may function as a nursery for juvenile spiny lobsters but that the use of this habitat depends on shelter characteristics and the isolation of islands.
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Kellogg, Christina A., Ryan P. Moyer, Mary Jacobsen, and Kimberly Yates. "Identifying mangrove-coral habitats in the Florida Keys." PeerJ 8 (August 24, 2020): e9776. http://dx.doi.org/10.7717/peerj.9776.
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Coral reefs are degrading due to many synergistic stressors. Recently there have been a number of global reports of corals occupying mangrove habitats that provide a supportive environment or refugium for corals, sheltering them by reducing stressors such as oxidative light stress and low pH. This study used satellite imagery and manual ground-truthing surveys to search for mangrove-coral habitats in the Florida Keys National Marine Sanctuary and then collected basic environmental parameters (temperature, salinity, dissolved oxygen, pHNBS, turbidity) at identified sites using a multi-parameter water quality sonde. Two kinds of mangrove-coral habitats were found in both the Upper and Lower Florida Keys: (1) prop-root corals, where coral colonies were growing directly on (and around) mangrove prop roots, and (2) channel corals, where coral colonies were growing in mangrove channels under the shade of the mangrove canopy, at deeper depths and not in as close proximity to the mangroves. Coral species found growing on and directly adjacent to prop roots included Porites porites (multiple morphs, including P. divaricata and P. furcata), Siderastrea radians, and Favia fragum. Channel coral habitats predominantly hosted S. radians and a few S. siderea, although single colonies of Solenastrea bournoni and Stephanocoenia intersepta were observed. Although clear, low-turbidity water was a consistent feature of these mangrove-coral habitats, the specific combination of environmental factors that determine which mangrove habitats are favorable for coral recruitment remains to be defined. Circumstantial evidence suggests additional coral communities existed on mangrove shorelines of oceanside and backcountry islands until destroyed, likely by Hurricane Irma. These mangrove-coral habitats may be climate refugia for corals and could be included in ecosystem management plans and considered for their applications in coral restoration.
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Sadhukhan, Koushik, Ramesh Chatragadda, T. Shanmugaraj, and M. V. Ramana Murthy. "New recruitment of staghorn corals in the Gulf of Mannar – the emergence of a resilient coral reef." Journal of Threatened Taxa 11, no. 14 (November 26, 2019): 14908–11. http://dx.doi.org/10.11609/jott.4767.11.14.14908-14911.
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Coral Reefs in Gulf of Mannar is degrading with fatser rate due to several environmental stress over the past few decades. Under this severe degredation phase, our work has observed significant coral recruitment at Hare Island and Manoli & Manoliputti Island of Gulf of Mannar. Occurrenc of new recruitment of corals increseas the live coral cover percentage upto 58.4% and 51.5% in both Islands respectively. The findings reported here that increased percentage of coral cover brings a new hope for the researcher to find out the possible driving forces to the successful post larval settlement and survival of the new recruits which results in better conservation and management plan for the coral reefs of GoM Marine National Park.
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Edmunds, Peter J. "Recruitment hotspots and bottlenecks mediate the distribution of corals on a Caribbean reef." Biology Letters 17, no. 7 (July 2021): 20210149. http://dx.doi.org/10.1098/rsbl.2021.0149.
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Recruitment hotspots are locations where organisms are added to populations at high rates. On tropical reefs where coral abundance has declined, recruitment hotspots are important because they have the potential to promote population recovery. Around St. John, US Virgin Islands, coral recruitment at five sites revealed a hotspot that has persistent for 14 years. Recruitment created a hotspot in density of juvenile corals that was 600 m southeast of the recruitment hotspot. Neither hotspot led to increased coral cover, thus revealing the stringency of the demographic bottleneck impeding progression of recruits to adult sizes and preventing population growth. Recruitment hotspots in low-density coral populations are valuable targets for conservation and sources of corals for restoration.
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Nurhasima, Aditya Hikmat Nugraha, and Dedy Kurniawan. "HARD CORAL (SCLERACTINIA) RECRUITMENT BASED ON THE GEOMORPHOLOGY ZONE IN BINTAN ISLAND WATERS, RIAU ISLANDS." Jurnal Ilmu dan Teknologi Kelautan Tropis 13, no. 2 (August 31, 2021): 269–81. http://dx.doi.org/10.29244/jitkt.v13i2.34551.
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The health of coral reef ecosystems can be seen through the emergence of coral recruitment. Aim of this research was to compared the scleractinia coral recruitment list based on genus, life form, and variations in size of the scleractinia coral recuit in the waters of Kampung Baru Lagoi and Teluk Bakau Village, Bintan Regency by geomorfology zone. The research was conducted using a Purposive sampling method in consideration of the presence of scleractinia coral in reef flat and reef slope areas using a 1x1 m square frame mounted along a 70 m transverse line parallel to the shoreline. Research has found 164 colonies of 24 genus dominated by Favia and Favites. Based on the most extensive life form of Coral encrusting and Coral massive variations in size 4.5-6 cm or medium category. The results of t test showed that the geomorphological differences in the research locations did not have a significant impact on the abundance of corals recruitment
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Yates, K. K., C. S. Rogers, J. J. Herlan, G. R. Brooks, N. A. Smiley, and R. A. Larson. "Diverse coral communities in mangrove habitats suggest a novel refuge from climate change." Biogeosciences 11, no. 16 (August 19, 2014): 4321–37. http://dx.doi.org/10.5194/bg-11-4321-2014.
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Abstract. Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business-as-usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove–coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality, and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove-shaded and exposed (unshaded) areas. Over 30 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies were living shaded by mangroves, and no shaded colonies were bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies were bleached. A combination of substrate and habitat heterogeneity, proximity of different habitat types, hydrographic conditions, and biological influences on seawater chemistry generate chemical conditions that buffer against ocean acidification. This previously undocumented refuge for corals provides evidence for adaptation of coastal organisms and ecosystem transition due to recent climate change. Identifying and protecting other natural, non-reef coral refuges is critical for sustaining corals and other reef species into the future.
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Yates, K. K., C. S. Rogers, J. J. Herlan, G. R. Brooks, N. A. Smiley, and R. A. Larson. "Mangrove habitats provide refuge from climate change for reef-building corals." Biogeosciences Discussions 11, no. 3 (March 31, 2014): 5053–88. http://dx.doi.org/10.5194/bgd-11-5053-2014.
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Abstract. Risk analyses indicate that more than 90% of the world's reefs will be threatened by climate change and local anthropogenic impacts by the year 2030 under "business as usual" climate scenarios. Increasing temperatures and solar radiation cause coral bleaching that has resulted in extensive coral mortality. Increasing carbon dioxide reduces seawater pH, slows coral growth, and may cause loss of reef structure. Management strategies include establishment of marine protected areas with environmental conditions that promote reef resiliency. However, few resilient reefs have been identified, and resiliency factors are poorly defined. Here we characterize the first natural, non-reef, coral refuge from thermal stress and ocean acidification and identify resiliency factors for mangrove–coral habitats. We measured diurnal and seasonal variations in temperature, salinity, photosynthetically active radiation (PAR), and seawater chemistry; characterized substrate parameters; and examined water circulation patterns in mangrove communities where scleractinian corals are growing attached to and under mangrove prop roots in Hurricane Hole, St. John, US Virgin Islands. Additionally, we inventoried the coral species and quantified incidences of coral bleaching, mortality and recovery for two major reef-building corals, Colpophyllia natans and Diploria labyrinthiformis, growing in mangrove shaded and exposed (unshaded) areas. At least 33 species of scleractinian corals were growing in association with mangroves. Corals were thriving in low-light (more than 70% attenuation of incident PAR) from mangrove shading and at higher temperatures than nearby reef tract corals. A higher percentage of C. natans colonies was living shaded by mangroves, and no shaded colonies bleached. Fewer D. labyrinthiformis colonies were shaded by mangroves, however more unshaded colonies bleached. A combination of substrate and habitat heterogeniety, proximity of different habitat types, hydrographic conditions, and biological influences on seawater chemistry generate chemical conditions that buffer against ocean acidification. This previously undocumented refuge for corals provides evidence for adaptation of coastal organisms and ecosystem transition due to recent climate change. Identifying and protecting other natural, non-reef coral refuges is critical for sustaining corals and other reef species into the future.
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Baum, Gunilla, Indra Januar, Sebastian C. A. Ferse, Christian Wild, and Andreas Kunzmann. "Abundance and physiology of dominant soft corals linked to water quality in Jakarta Bay, Indonesia." PeerJ 4 (November 29, 2016): e2625. http://dx.doi.org/10.7717/peerj.2625.
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Declining water quality is one of the main reasons of coral reef degradation in the Thousand Islands off the megacity Jakarta, Indonesia. Shifts in benthic community composition to higher soft coral abundances have been reported for many degraded reefs throughout the Indo-Pacific. However, it is not clear to what extent soft coral abundance and physiology are influenced by water quality. In this study, live benthic cover and water quality (i.e. dissolved inorganic nutrients (DIN), turbidity (NTU), and sedimentation) were assessed at three sites (< 20 km north of Jakarta) in Jakarta Bay (JB) and five sites along the outer Thousand Islands (20–60 km north of Jakarta). This was supplemented by measurements of photosynthetic yield and, for the first time, respiratory electron transport system (ETS) activity of two dominant soft coral genera,Sarcophytonspp. andNephtheaspp. Findings revealed highly eutrophic water conditions in JB compared to the outer Thousand Islands, with 44% higher DIN load (7.65 μM/L), 67% higher NTU (1.49 NTU) and 47% higher sedimentation rate (30.4 g m−2d−1). Soft corals were the dominant type of coral cover within the bay (2.4% hard and 12.8% soft coral cover) compared to the outer Thousand Islands (28.3% hard and 6.9% soft coral cover). Soft coral abundances, photosynthetic yield, and ETS activity were highly correlated with key water quality parameters, particularly DIN and sedimentation rates. The findings suggest water quality controls the relative abundance and physiology of dominant soft corals in JB and may thus contribute to phase shifts from hard to soft coral dominance, highlighting the need to better manage water quality in order to prevent or reverse phase shifts.
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Permana, Rizki Dimas, Sunarto Sunarto, Syawalludin Alisyahbana Harahap, Indah Riyantini, and Yuwanda Ilham. "Potassium Cyanide (KCN) Content in Coral Reefs and Its Effect on The Abundance of Indicator-Fishes in The Anambas Islands." Journal of Science and Applicative Technology 5, no. 1 (May 28, 2021): 214. http://dx.doi.org/10.35472/jsat.v5i1.381.
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The coral reef ecosystem has been continuously degraded in various parts of Indonesia, including the Anambas Islands. This research aimed to discover the content of Potassium Cyanide (KCN) accumulated on corals and the effect on indicator fishes abundance in the Anambas Islands. This research was conducted at 25 observation stations in the Anambas Islands National Marine Protected Area. The potassium cyanide (KCN) content was tested with the principle of titration and distillation. The coral samples used ranged from 10-20 g diluted in 100-200 ml distilled water. The method used to determine the abundance of indicator fish was underwater visual census or UVC, which recorded fish in every station. This research recorded 307 fish individuals from 14 species of the Chaetodontidae family. Potassium Cyanide's content on corals was high ranging from 0,009-0,032 mg/L with an average 0,0205 mg/L. We concluded that there was a negative correlation between the content of Potassium Cyanide (KCN) on corals and indicator fishes abundance, which means the higher the Potassium Cyanide content (KCN) is on corals, the lower the indicator fishes abundance will point out.
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Ali, Amjad, Rupert Ormond, Wera Leujak, and Pirzada Jamal A. Siddiqui. "Distribution, diversity and abundance of coral communities in the coastal waters of Pakistan." Journal of the Marine Biological Association of the United Kingdom 94, no. 1 (September 10, 2013): 75–84. http://dx.doi.org/10.1017/s0025315413001203.
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We assessed the distribution, diversity and abundance of corals in Pakistani waters. A total of 29 hard coral species (eight families and 14 genera), one black coral species and eight soft coral species (three families and seven genera) were recorded from 18 dive sites at nine locations along the coastline. Distribution of hard corals was extremely poor at Mubarak Village and Sandspit, and corals were not found at Goth Abdul Rehman, Gadani (Kuchiani) and Buleji. Moderately rich coral communities were recorded at Churna Island and at more exposed sites around Astola Island. By contrast highly diverse hard coral communities, with up to 80% cover, were found only at the northern sheltered side of Astola Island where Favites complanata, Favites pentagona, Coscinaraea monile and Porites nodifera were the most abundant species. Favites complanata was recorded from most dive sites at Astola Island. Porites nodifera and Pocillopora damicornis, and to a lesser extent Porites harrisoni, Leptastrea pruinosa and Psammocora obtusangulata formed large single species stands. No ‘true’ coral reef was found at any dive site; however, the formation of proto-reefs was evident around Astola Island. Soft corals were dominant at most exposed sites, particularly at Ormara (Roadrigues Shoals) and Jiwani. By comparing diversity with other locations in the region, corals distribution and growth appear to be fairly poor in Pakistan.
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Amjad, Shahid, Nuzhat Khan, and Saira Ishaq. "Coral Community: Preliminary Biodiversity Survey of Churna Island, Northern Arabian Sea." April 2020 39, no. 2 (April 1, 2020): 390–97. http://dx.doi.org/10.22581/muet1982.2002.15.
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Biodiversity survey between Cape Monze and Churna Island was carried out for the assessment of coral assemblages in the area. During the present study, diving surveys were conducted to document the living corals that included deep sea coral, Coelenterates, Bryozoans, Gorgonia (Sea Fan), Scleractinian, (Stony Corals) Cnidaria (Hydroids), Porites (Small Polyp Stony), Pocilopora (Cauliflower Corals), Acropora (Hard Corals), sea urchins, sea anemones, coral fish spp, sea slugs, stone fish and bivalves were observed and documented. To have a better understanding of the distribution pattern “Shannon Weiner Biodiversity Index” for species diversity “H” (0.845-1.176) and evenness “J” (0.962-0.937) were calculated, the values indicate that the coral species were evenly distributed and did not show any significant variation in the area. Budding coral communities were observed at the sedimentary rock of Churna in patches, and showed a random distribution behavior all along the surveyed area. Random, scattered and aggregate distribution patterns of corals may be due to the wave beaten physical environment of Churna Island that do not allow sustainable growth of coral communities. Moreover, the high energy waves and water currents destablize and erode the sedimentary substrate on which corals grow. The corals are therefore unable to establish themselves to form a natural reef due to loss of natural living and non-living substrate. The ecology of Churna Island also under the influence of nearby coastal industries, and the Hub River influx causing floods in the SW monsoon period that may destablize rubble and increase the seawater turbidity level. These environmental factors contributing to the deterioration of present day corals, and larval settlement. It may be concluded that biological resources are renewable and can even increase with proper management techniques. Breakwater wall and artificial substrate must be encouraged to further facilitate the growth and development of Corals in the area.
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Amjad, Shahid, Nuzhat Khan, and Saira Ishaq. "Coral Community: Preliminary Biodiversity Survey of Churna Island, Northern Arabian Sea." April 2020 39, no. 2 (April 1, 2020): 390–97. http://dx.doi.org/10.22581/10.22581/muet1982.2002.15.
Full textAbstract:
Biodiversity survey between Cape Monze and Churna Island was carried out for the assessment of coral assemblages in the area. During the present study, diving surveys were conducted to document the living corals that included deep sea coral, Coelenterates, Bryozoans, Gorgonia (Sea Fan), Scleractinian, (Stony Corals) Cnidaria (Hydroids), Porites (Small Polyp Stony), Pocilopora (Cauliflower Corals), Acropora (Hard Corals), sea urchins, sea anemones, coral fish spp, sea slugs, stone fish and bivalves were observed and documented. To have a better understanding of the distribution pattern “Shannon Weiner Biodiversity Index” for species diversity “H” (0.845-1.176) and evenness “J” (0.962-0.937) were calculated, the values indicate that the coral species were evenly distributed and did not show any significant variation in the area. Budding coral communities were observed at the sedimentary rock of Churna in patches, and showed a random distribution behavior all along the surveyed area. Random, scattered and aggregate distribution patterns of corals may be due to the wave beaten physical environment of Churna Island that do not allow sustainable growth of coral communities. Moreover, the high energy waves and water currents destablize and erode the sedimentary substrate on which corals grow. The corals are therefore unable to establish themselves to form a natural reef due to loss of natural living and non-living substrate. The ecology of Churna Island also under the influence of nearby coastal industries, and the Hub River influx causing floods in the SW monsoon period that may destablize rubble and increase the seawater turbidity level. These environmental factors contributing to the deterioration of present day corals, and larval settlement. It may be concluded that biological resources are renewable and can even increase with proper management techniques. Breakwater wall and artificial substrate must be encouraged to further facilitate the growth and development of Corals in the area.
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Weisler, Marshall I., Quan Hua, and Jian-xin Zhao. "Late Holocene14C Marine Reservoir Corrections for Hawai'I Derived from U-Series Dated Archaeological Coral." Radiocarbon 51, no. 3 (2009): 955–68. http://dx.doi.org/10.1017/s0033822200034032.
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The first application of U-series dating and accelerator mass spectrometry (AMS) assay of Polynesian archaeologicalPocilloporaspp. branch corals for deriving a precise local marine reservoir correction (ΔR) is described. Known-age corals were selected that spanned the entire culture-historical sequence for the Hawaiian Islands, thus eliminating the problem of not having known-age dated samples that cover the period of direct relevance to prehistorians; in this case, about AD 700–1800. Dating coral samples from windward and leeward coastlines of Moloka'i Island, with different offshore conditions such as upwelling, currents, wind patterns, coastal topography, and straight or embayed shorelines, provides insights into possible variations of local conditions on the same island—something that has never been attempted. In this regard, there was no spatial variability in ΔR during the 17th century. We report a weighted average ΔR value for Moloka'i Island of 52 ± 25 yr using 12 pair-dated dedicatory branch corals from religious archaeological sites and demonstrate that there is no significant temporal variability in ΔR between about AD 700 to 1800. In combination with 4 selected previously published ΔR values based on pre-bomb known-age marine shells, a revised ΔR of 66 ± 54 yr is established for the Hawaiian Islands. However, future research should examine the archipelago-wide spatial variability in ΔR with the analysis of additional dated archaeological coral samples.
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Liao, Zhiheng, Kefu Yu, Yinghui Wang, Xueyong Huang, and Lijia Xu. "Coral-algal interactions at Weizhou Island in the northern South China Sea: variations by taxa and the exacerbating impact of sediments trapped in turf algae." PeerJ 7 (March 13, 2019): e6590. http://dx.doi.org/10.7717/peerj.6590.
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Competitive interactions between corals and benthic algae are increasingly frequent on degrading coral reefs, but the processes and mechanisms surrounding the interactions, as well as the exacerbating effects of sediments trapped in turf algae, are poorly described. We surveyed the frequency, proportion, and outcomes of interactions between benthic algae (turf algae and macroalgae) and 631 corals (genera: Porites, Favites, Favia, Platygyra, and Pavona) on a degenerating reef in the northern South China Sea, with a specific focus on the negative effects of algal contact on corals. Our data indicated that turf algae were the main algal competitors for each surveyed coral genus and the proportion of algal contact along the coral edges varied significantly among the coral genera and the algal types. The proportions of algal wins between corals and turf algae or macroalgae differed significantly among coral genera. Compared to macroalgae, turf algae consistently yielded more algal wins and fewer coral wins on all coral genera. Amongst the coral genera, Porites was the most easily damaged by algal competition. The proportions of turf algal wins on the coral genera increased 1.1–1.9 times in the presence of sediments. Furthermore, the proportions of algal wins on massive and encrusting corals significantly increased with the combination of sediments and turf algae as the algal type. However, the variation in proportions of algal wins between massive and encrusting corals disappeared as sediments became trapped in turf algae. Sediments bound within turf algae further induced damage to corals and reduced the competitive advantage of the different coral growth forms in their competitive interactions with adjacent turf algae.
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Quang, Thai Minh. "Morphology, abundance and the invasiveness of coral-killing sponge Chalinula nematifera (Porifera: Demosponigiae) from Con Dao National Park, Vietnam." Tạp chí Khoa học và Công nghệ biển 20, no. 4A (April 11, 2021): 95–103. http://dx.doi.org/10.15625/1859-3097/15651.
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This is the first study on morphology, abundance and invasion of coral-killing sponge Chalinula nematifera (De Laubenfels, 1954) from offshore waters in Con Dao islands, Vietnam. The results of the study show that the morphology is similar to that in the Western Pacific, but differs in skeletal structure compared to the description in the Eastern Pacific. The density of C. nematifera (average ± standard deviation) is 2.02 ± 5.03 colonies per 100 m2 (present at 12/15 survey stations) with the number of colonization belonging to diameter group 5–20 cm. They invade 30 species belonging to 23 genera of Scleractinia corals (44.7% on foliose/laminar and encrusting coral, 23.86% on massive coral and 21.97% on branching coral). The ability to invade corals of C. nematifera does not limit the host. So, this is considered a potential hazard to the East Vietnam Sea coral reefs in the future.
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Rogers, Caroline S. "Immediate Effects of Hurricanes on a Diverse Coral/Mangrove Ecosystem in the U.S. Virgin Islands and the Potential for Recovery." Diversity 11, no. 8 (August 12, 2019): 130. http://dx.doi.org/10.3390/d11080130.
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Hurricanes Irma and Maria, two powerful storms that hit the U.S. Virgin Islands less than 2 weeks apart in September 2017, caused extensive damage to the natural resources on St. John. Damage was particularly severe in a unique mangrove/coral ecosystem in three bays within Virgin Islands Coral Reef National Monument, a National Park Service marine protected area. Many Red Mangrove (Rhizophora mangle) trees were uprooted and tossed into the sea, and the prop roots of others were stripped of corals, sponges and other marine life. No other mangrove area in the Caribbean is known to have so many scleractinian corals (about 30 species before the storms). Although many corals were overturned or buried in rubble, colonies of most of the species, including four that are listed as threatened under the U.S. Endangered Species Act, survived. Recovery of this ecosystem will depend on Red Mangrove propagules becoming established and producing prop roots to support rich marine life along with a canopy to provide the shade that was critical to the biodiversity that was present before the storms. Unlike in many situations where major disturbances reduce coral cover, the substrate that must be restored for full recovery to occur is a living substrate—the prop roots of the mangroves. Larvae of corals and sponges will need to recruit on to the roots. Future storms could hinder this process.
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Morrow, Kathleen M., Anthony G. Moss, Nanette E. Chadwick, and Mark R. Liles. "Bacterial Associates of Two Caribbean Coral Species Reveal Species-Specific Distribution and Geographic Variability." Applied and Environmental Microbiology 78, no. 18 (July 6, 2012): 6438–49. http://dx.doi.org/10.1128/aem.01162-12.
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ABSTRACTScleractinian corals harbor microorganisms that form dynamic associations with the coral host and exhibit substantial genetic and ecological diversity. Microbial associates may provide defense against pathogens and serve as bioindicators of changing environmental conditions. Here we describe the bacterial assemblages associated with two of the most common and phylogenetically divergent reef-building corals in the Caribbean,Montastraea faveolataandPorites astreoides. Contrasting life history strategies and disease susceptibilities indicate potential differences in their microbiota and immune function that may in part drive changes in the composition of coral reef communities. The ribotype structure and diversity of coral-associated bacteria within the surface mucosal layer (SML) of healthy corals were assessed using denaturing gradient gel electrophoresis (DGGE) fingerprinting and 454 bar-coded pyrosequencing. Corals were sampled at disparate Caribbean locations representing various levels of anthropogenic impact. We demonstrate here thatM. faveolataandP. astreoidesharbor distinct, host-specific bacteria but that specificity varies by species and site.P. astreoidesgenerally hosts a bacterial assemblage of low diversity that is largely dominated by one bacterial genus,Endozoicomonas, within the orderOceanospirillales. The bacterial assemblages associated withM. faveolataare significantly more diverse and exhibit higher specificity at the family level thanP. astreoidesassemblages. Both corals have more bacterial diversity and higher abundances of disease-related bacteria at sites closer to the mainland than at those furthest away. The most diverse bacterial taxa and highest relative abundance of disease-associated bacteria were seen for corals near St. Thomas, U.S. Virgin Islands (USVI) (2.5 km from shore), and the least diverse taxa and lowest relative abundance were seen for corals near our most pristine site in Belize (20 km from shore). We conclude that the two coral species studied harbor distinct bacterial assemblages within the SML, but the degree to which each species maintains specific microbial associations varies both within each site and across large spatial scales. The taxonomic scale (i.e., phylum versus genus) at which scientists examine coral-microbe associations, in addition to host-elicited factors and environmental fluctuations, must be considered carefully in future studies of the coral holobiont.
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Erviana, Renanda Nur, Pujiono Wahyu Purnomo, and Supriharyono Supriharyono. "Class Conservation Morfologi Karang berdasarkan Kedalaman pada Struktur Terumbu Karang di Pulau Kemujan dan Pulau Sintok, Karimunjawa, Jawa Tengah Coral Morphology Class Conservation Based on Depth of Coral Reef Structure in Kemujan and Sintok Islands, Karimunjawa, Central Java." Management of Aquatic Resources Journal (MAQUARES) 9, no. 2 (June 12, 2020): 123–30. http://dx.doi.org/10.14710/marj.v9i2.27768.
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ABSTRAKKemujan dan Sintok merupakan pulau yang termasuk ke dalam zona pemanfaatan sebagai wisata bahari dan memiliki keanekaragaman bentuk pertumbuhan karang yang tinggi. Bentuk pertumbuhan karang dibedakan menjadi karang acropora dan non-acopora dengan perbedaan morfologi seperti tipe branching, massive, encruisting, foliose, dan digitae. Analisis morfologi karang sebagai pendukung status penutupan karang dapat mengetahui kondisi terumbu karang sesuai class conservation. Tujuan penelitian ini mengetahui kualitas perairan, struktur terumbu karang, morfologi karang berdasarkan class conservation dan pengaruh kedalaman terhadap struktur serta morfologi karang di Pulau Kemujan dan Sintok. Pengambilan data dilaksanakan pada bulan November 2019. Metode penelitian yang digunakan adalah metode Underwater Photo Transect (UPT) dengan menggunakan transek sepanjang 30 meter. Data yang diambil adalah parameter kualitas perairan dan foto underwater karang. Data hasil penelitian diolah menggunakan aplikasi CPCe (Coral Point Count with Excel extensions) dan uji non parametrik dengan SPSS serta dianalisis menggunakan diagram r-K-S. Hasil penelitian menunjukkan bahwa kualitas perairan pada lokasi penelitian masih dalam keadaan normal. Persentase kelimpahan karang hidup termasuk dalam kategori sedang sampai dengan sangat baik yaitu berkisar 25,56 -76,22%. Persentase morfologi karang berdasarkan Class conservation secara umum memiliki dominasi kelompok kompetitors (K) atau CC=2 yang berkisar 48,72 – 76,5%, hal ini menunjukkan bahwa pada lokasi penelitian didominasi karang bentuk branching maupun foliose serta tidak ada pengaruh signifikan kedalaman air terhadap morfologi karang. ABSTRACTKemujan and Sintok are islands in the utilization zone as marine tourism and have high diversity of coral growth forms. The coral’s life form can be grouped into acropora and non-acopora corals with morphological differences such as branching, massive, encruisting, foliose, and digitae types. Morphological analysis of corals as supporting the status of coral cover can determine the condition of coral reefs according to class conservation. The purpose of this study are to determine the quality of the waters, the structure of coral reefs, coral morphology based on class conservation and the influence of depth on the structure and morphology of corals in Kemujan and Sintok Islands. Data collection was carried out in November 2019. The research method used was the Underwater Photo Transect (UPT) method using a 30 meter transect. The data collected the parameters of water quality and underwater coral photos. The research data were processed using the CPCe (Coral Point Count with Excel extensions) application and non-parametric tests with SPSS and analyzed using the r-K-S diagram. The results showed that the water quality at the study area was still in a normal condition. However, there was no significant effect of water depth on coral morphology. The percentage of live coral abundance was included in the moderate to very good category, ranging from 25.56 to 76.22%. Percentage of coral morphology based on Class conservation generally has a predominance of competitor groups (K) or CC = 2 ranging from 48.72 - 76.5%. Moreover, the results show that based on the coral growth forms at the study sites were dominated by branching and foliose corals and there was no significant effect of water depth on coral morphology.
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Willingham-McLain, Gary. "Darwin's “Eye of Reason”: Natural Selection and the Mathematical Sublime." Victorian Literature and Culture 25, no. 1 (1997): 67–85. http://dx.doi.org/10.1017/s1060150300004630.
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According to charles darwin's subsidence theory of coral reef formation, coral polyps laid the foundation fifty million years ago for a Pacific reef now known as Enewetak Atoll (Wood 12). At that time Enewetak was simply a ring of coral around the fringe of a sinking island mountain. Able to live only near the ocean's surface, however, corals build upon previous generations of coral structure as their land base sinks, and in the case of Enewetak this process continued long after the mountain's peak first submerged. Today Enewetak Atoll rises above the original mountain seven-tenths of a mile (two-and-a-half times the height of the Chicago Sears Tower) before it reaches its apex in a circle of lagoon islands on the ocean's surface.
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Bessell-Browne, Pia, Hannah E. Epstein, Nora Hall, Patrick Buerger, and Kathryn Berry. "Severe Heat Stress Resulted in High Coral Mortality on Maldivian Reefs following the 2015–2016 El Niño Event." Oceans 2, no. 1 (March 3, 2021): 233–45. http://dx.doi.org/10.3390/oceans2010014.
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Coral cover worldwide has been declining due to heat stress caused by climate change. Here we report the impacts of the 2015–2016 El Niño mass coral bleaching event on the coral cover of reefs located on central and northern atolls of the Maldives. We surveyed six reef sites in the Alifu Alifu (Ari) and Baa (South Maalhosmadulu) Atolls using replicate 20 m benthic photo transects at two depths per reef site. Live and recently dead coral cover identified from images differed between reef sites and depth. Recently dead corals on average made up 33% of the coral assemblage at shallow sites and 24% at deep sites. This mortality was significantly lower in massive corals than in branching corals, reaching an average of only 6% compared to 41%, respectively. The best predictors of live coral cover were depth and morphology, with a greater percentage of live coral at deep sites and in massive corals. The same predictors best described the prevalence of recently dead coral, but showed inverse trends to live coral. However, there was high variability among reef sites, which could be attributed to additional local stressors. Coral bleaching and resulting coral mortalities, such as the ones reported here, are of particular concern for small island nations like the Maldives, which are reliant on coral reefs.
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Harriott, Vicki J., Simon A. Banks, Roland L. Mau, Darren Richardson, and Lisa G. Roberts. "Ecological and conservation significance of the subtidal rocky reef communities of northern New South Wales, Australia." Marine and Freshwater Research 50, no. 4 (1999): 299. http://dx.doi.org/10.1071/mf98042.
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The subtropical rocky reefs of Cook Island, Julian Rocks and the South West Rocks area form part of a chain of islands and reefs with significant coral cover from the Queensland border (28˚S) to the southern extent of extensive coral communities in coastal Australia (31˚S). Benthic communities at 18 subtidal sites at the three localities were surveyed quantitatively by video-transects, and coral species lists were compiled. Twenty-eight coral species previously unrecorded for these localities were identified, increasing the species richness of hermatypic corals reported for the northern NSW region (excluding the Solitary Islands) from 14 to 43. Coral species richness declined with latitude. Benthic communities were generally dominated by turfing and macroalgal species, with Pyura, sponges, and barnacles locally abundant. Scleractinian coral cover ranged from 0% to 42.6% per site, with highest coral cover at the most southern site. Julian Rocks is a designated Aquatic Reserve, and Marine Parks have been suggested for all three localities. Selection of Marine Protected Areas requires information on their ecological significance. These surveys report the first quantitative information on the shallow- water, rocky-reef communities in the region, which is a vital step in assessing their ecological significance.
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Dalton, S. J., S. Godwin, S. D. A. Smith, and L. Pereg. "Australian subtropical white syndrome: a transmissible, temperature-dependent coral disease." Marine and Freshwater Research 61, no. 3 (2010): 342. http://dx.doi.org/10.1071/mf09060.
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Since 2000, a disease displaying white-syndrome characteristics has been observed affecting corals from the genus Turbinaria in the Solitary Islands Marine Park, New South Wales, Australia. Recently termed Australian subtropical white syndrome, this disease is transmissible through direct contact and by a predatory vector, but transmission through the water column has not been observed. In aquarium experiments, progressive tissue loss, extending from the region where healthy Turbinaria mesenterina fragments were in direct contact with samples of diseased coral, was noted in 66% of treatments. No tissue loss occurred in any of the controls or when healthy fragments were not in direct contact with diseased corals. Field experiments confirmed that the disease was infectious through direct contact. Further experiments showed that the rate of tissue loss was significantly higher when corals were exposed to summer temperatures (26°C). These results suggest that temperature increases predicted in most climate change models could lead to the loss of dominant coral species, displacing other organisms that rely on corals for food and shelter. Finally, the present study showed that removal of the disease margin provides a management tool to minimise coral tissue loss during an epizootic.
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Burns, J. H. R., A. Fukunaga, K. H. Pascoe, A. Runyan, B. K. Craig, J. Talbot, A. Pugh, and R. K. Kosaki. "3D HABITAT COMPLEXITY OF CORAL REEFS IN THE NORTHWESTERN HAWAIIAN ISLANDS IS DRIVEN BY CORAL ASSEMBLAGE STRUCTURE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W10 (April 17, 2019): 61–67. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w10-61-2019.
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<p><strong>Abstract.</strong> Corals act as ecosystem engineers by secreting structurally complex calcium carbonate skeletons on the benthic substrate that provide habitat for a diverse array of associated reef organisms. Communities of living corals create large and dynamic benthic structures that directly affect ecological parameters such as habitat provisioning and light availability, thus influencing overall ecosystem function. Despite the important role 3D structural complexity plays in ecosystem biodiversity and productivity, the field of coral ecology has lacked accessibility to practical technology capable of quantifying 3D characteristics of underwater habitats. Advancements in the field of computer vision has led to Structure-from-Motion (SfM) photogrammetry, which provides a simple and cost-effective method for creating high-resolution and spatially accurate 3D reconstructions of natural environments. Integrating SfM approaches into coral reef research and monitoring has provided useful insight into the relationship between 3D habitat complexity and ecological processes. In this study, we examined the relationships among 2D estimates of live coral cover and several metrics of 3D habitat structural complexity among eleven long-term monitoring sites at French Frigate Shoals. Our findings show that coral assemblage structure acts as a significant driver of 3D structural complexity of coral reef habitats at this atoll. This study highlights the importance of diverse and abundant coral assemblages in supporting structurally complex coral reef habitats and provides a framework for future investigations into the ecological role of various coral morphotypes.</p>
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Tombokan, John L., Unstain N. W. J. Rembet, and Silvester B. Pratasik. "Vertical Distribution Of Hard Corals In Southern Siladen Island." JURNAL ILMIAH PLATAX 5, no. 1 (January 19, 2017): 49. http://dx.doi.org/10.35800/jip.5.1.2017.14972.
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This study was aimed at provide information on hard coral distribution in southern Siladen Island. The work was done using SCUBA gear Line Intercept Transect (LIT). Thirty m long-line transects were placed at the reef flat, 5 m depth, 10 m depth, 15 m depth, and 20 m depth. A total of 44 hard coral genera was recorded, and the highest number of genre was found at 5 m depth. Coral species diversity was also high enough at the reef flat (1.032) and 5 m depth (1.28). Coral reef condition at 10 m depth was good enough as well and categorized as productive due to much higher percent of the biotic component than the abiotic component. The dominant life forms consisted of tabulate Acropora and branching corals at the reef flat, encrusting corals, branching corals, and foliose corals at 5 m, encrusting corals at 10 and 20 m depth, and massive corals, encrusting corals, and branching corals at 15 m depth, respectively. Keywords: coral reef, distribution, LIT, vertical zonationl. Abstrak Penelitian ini bertujuan untuk menyediakan informasi tentang distribusi karang batu di sebelah selatan pulau Siladen. Penelitian ini dilakukan menggunakan alat selam SCUBA dan metode transek intersep garis. Tali transek sepanjang 30 m diletakkan di rataan terumbu, kedalaman 5, 10, 15, dan 20 m. Total 44 genera karang batu ditemukan pada penelitian ini, dan jumlah genera terbanyak ditemukan pada kedalaman 5 m. Keanekaragaman spesies karang juga cukup tinggi di daerah rataan terumbu (1,032) and 5m (1,28). Kondisi terumbu karang pada kedalaman 10 m juga cukup baik dan dikategorikan produktif karena tingginya komponen biotik dibandingkan dengan komponen abiotik. Bentuk pertumbuhan yang dominan masing-masing terdiri dari Acropora meja dan karang bercabang di rataan terumbu karang, karang encrusting, karang bercabang, dan foliose pada kedalaman 5 m, karang encrusting pada kedalaman 10 dan 20m, serta karang masif, karang encrusting dan karang bercabang pada kedalaman 15m. Kata kunci: Terumbu karang, distribusi, Transek Intersep Garis, Zonasi vertikal.
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Munasik, Munasik, Muhammad Helmi, Rikoh Manogar Siringoringo, and Suharsono Suharsono. "Pemetaan Kerusakan Terumbu Karang Akibat Kandasnya Kapal Tongkang di Taman Nasional Karimunjawa, Jawa Tengah." Journal of Marine Research 9, no. 3 (July 16, 2020): 343–54. http://dx.doi.org/10.14710/jmr.v9i3.28239.
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ABSTRAK: Pemetaan kerusakan terumbu karang akibat kandasnya kapal tongkang di P. Tengah dan di P. Cilik, Taman Nasional Karimunjawa, Jawa Tengah telah dilakukan 2-3 bulan setelah kejadian dengan cara mengukur luas area kerusakan dan menilai kondisi terumbu karang. Pengukuran area kerusakan menggunakan metode penginderaan jarak jauh berbasis Drone (UAV Drone/pesawat tanpa awak) dan penilaian kondisi ekosistem terumbu karang dengan menggunakan metode Underwater Photo Transect (UPT). Tujuan penelitian ini adalah untuk mengetahui kondisi dan kerusakan terumbu karang akibat kandasnya kapal tongkang di P. Cilik dan P. Tengah, Taman Nasional Karimunjawa. Hasil menunjukkan telah terjadi kerusakan fisik di lereng atas terumbu karang pada kedua pulau tersebut berupa karang mati dan pecahan karang. Luas kerusakan terumbu karang di P. Tengah (1.420,32 m2) lima kali lebih luas daripada luas kerusakan terumbu karang di P. Cilik (267,22 m2). Luasnya kerusakan terumbu karang di P. Tengah kemungkinan akibat perbedaan jumlah kapal tongkang yang kandas, waktu kandas dan dominasi karang yang mudah patah (fragile). Komunitas karang keras yang dominan di lereng terumbu P. Tengah adalah karang bercabang (CB), Acropora bercabang (ACB) dan karang lembaran/foliose (CF). Luasan kerusakan dan kondisi terumbu karang akibat kandasnya kapal tongkang ini dapat digunakan untuk pengelola kawasan konservasi dalam perencanaan perlindungan dan restorasi ekosistem terumbu karang di Taman Nasional Karimunjawa ABSTRACT: Mapping damage to coral reefs due to the barges grounding in Cilik Island (P. Cilik) and Tengah Island (P. Tengah), Karimunjawa National Park, Central Java was carried out 2-3 months after the event by measuring the extent of damage and coral reefs assessment. Damage area measurement using Drone (UAV Drone) based remote sensing and reef ecosystem assessment using the Underwater Photo Transect (UPT) method. The aim of this study was to determine the condition and damage of coral reefs due to the wrecking of barges in Cilik and Central P., Karimunjawa National Park The results show that physical damage has occurred on the upper slopes of coral reefs on both islands is dead coral and coral fragments. Damage to extensive coral reefs in P. Tengah (1,420.32 m2) is five times larger than extensive damage to coral reefs in P. Cilik (267.22 m2). Damage to coral reefs in P. Tengah may cause differences in the number of barges that ran aground, time of aground and the dominance of fragile corals the upper slopes of the coral reefs. The dominant hard coral communities on the upper slopes of P. Tengah reefs are generally composed the fragile corals, such as branching corals (CB), branching Acropora (ACB) and foliose corals (CF). Damage to coral reefs and the condition of the ecosystem caused by the aground of the barges can be used to manage conservation areas in the planning of conservation and restoration of coral reef ecosystems in the Karimunjawa National Park in near future.
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Nugraha, Muhammad Andre, Neviaty P. Zamani, and Hawis H. Madduppa. "GROWTH RATE, SPATIAL-TEMPORAL VARIATION AND PREVALENCE OF THE ENCRUSTING CYANOSPONGE (Terpios hoshinota) IN SERIBU ISLANDS, JAKARTA." Jurnal Ilmu dan Teknologi Kelautan Tropis 12, no. 3 (December 31, 2020): 761–78. http://dx.doi.org/10.29244/jitkt.v12i3.30885.
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Terpios hoshinota is a cyanosponge encrusted on the substrate in coral reefs that may cause mass mortality on the infested corals. This research was conducted to investigate the magnitude of damage level of corals due to the T. hoshinota outbreaks by assessing its growth rate, spatiotemporal variation, and prevalence between two sites in Seribu Islands. Four-time observation (T0-T3) in over 18 months (2016-2017) was conducted to see the growth level of sponge using a permanently quadratic photo transect method of 5x5 m (250.000cm2). The total coverage area of sponge on study site in the T0 was 65.252cm2 and becomes 81.066cm2 in T3. The highest level occurred on T2 of 2.051cm2/months in Dapur Island (the closest to Jakarta) and 483cm2/months in the Belanda Island (the further site). The highest sponge growth rate occurred on T1-T2 during transitional season from rainy to dry. The lowest growth rate was observed on T3 during transitional season from dry to rainy. In general, prevalence percentage was higher in Belanda Island than in Dapur Island. This study showed a persistence invasion of encrusting T. hoshinota on coral reef ecosystem that may overcome the function and role of associated organisms.
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Huda, Miftahul, Suwarno Hadisusanto, and Encus Widyatmoko. "CORAL REEF CONDITION AND HARD CORAL (SCLERACTINIA) COMUNITY IN LOCAL MARINE CONSERVATION AREA, BENGKAYANG, WEST KALIMANTAN." KnE Life Sciences 2, no. 1 (September 20, 2015): 507. http://dx.doi.org/10.18502/kls.v2i1.205.
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<p>Coral reef ecosystem has diverse shape and stunning beauty. It has high value on both ecological and economical aspect it has productivity greater than other marine life. Local Marine Conservation Area, Bengkayang, West Kalimantan (Lemukutan island, Penata Besar island, Penata Kecil island, Seluas island, Rahdayan island) has a high potential on coastal and marine natural resources especially coral reefs ecosystem. The study was purposed to determine the condition coral reef ecosystem and the diversity of hard corals (Scleractinia). Samples have been taking from 5-7 meters depth in every point using Line Intercept Transect method (LIT). The observation result from the coral reef in Local Marine Conservation Area showed as the followings varies from bad to good (13.82 – 69.00%), but biotic components were found in each area that consist of sediment with percentage of 4.32-37.68% and the rock of 2.57- 38.22%. Hard coral community consists of 35 species including seven families. Genus Acropora as hard coral species is dominating the five islands. The damage of coral reefs that occurs in most of the study area is due to increased suspended material (sediments). </p><p><strong>Keywords</strong>: Coral reefs, Scleractinia, Acropora, LIT, Local Marine Conservation Area, Bengkayang, West Kalimantan.</p>
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De Assis, José, Jose Souza, Manuela Lima, Gislaine Lima, Ralf Cordeiro, and Carlos Pérez. "Association between deep-water scale-worms (Annelida: Polynoidae) and black corals (Cnidaria: Antipatharia) in the Southwestern Atlantic." Zoologia 36 (June 18, 2019): 1–13. http://dx.doi.org/10.3897/zoologia.36.e28714.
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Polynoid scale-worms have been found living as commensals with deep-water antipatharians (commonly known as black corals) in the Potiguar Basin, off Rio Grande do Norte State, Northeastern Brazil. In this paper two polychaete species and four black corals species are redescribed. Benhamipolynoecf.antipathicola and Parahololepidellacf.greeffi, and the black coral Stylopathesadinocrada Opresko, 2006 are recorded for the Southwestern Atlantic. Benhamipolynoecf.antipathicola was first described from off New Zealand and the Malay Archipelago, as symbiont with the black coral Stylopathestenuispina (Silberfeld, 1909). It was later reported for the North Atlantic, off Florida, associated with Stylopathescolumnaris (Duchassaing, 1870). In our study, B.cf.antipathicola was found in association with the black coral S.adinocrada. Parahololepidellacf.greeffi was first described as a free-living from shallow waters off São Tomé and Cabo Verde Islands, West Africa, and later reported as symbiont with the black coral Tanacetipathescf.spinescens in the same location. Our data expand both the geographical distribution and the host range of this species which is reported for the first time as symbiont with Tanacetipathesbarbadensis (Brook, 1889), T.tanacetum (Pourtalès, 1880) and T.thamnea (Warner, 1981) in Brazil. The aim of this study is to discuss commensal associations between two species of scale-worm polynoids and black corals found in the Southwestern Atlantic, and also reporting their global distribution. Finally, we provided an updated list of the commensal polynoids and their black coral hosts.
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Ahmad Zubir, Ahmad Annuar, Yusri Yusof, and Mohd Al Amin Muhamad Nor. "Physical and Chemical Characteristics of Corals from Bidong Island, Terengganu, Malaysia." Advanced Materials Research 1112 (July 2015): 555–58. http://dx.doi.org/10.4028/www.scientific.net/amr.1112.555.
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Coral and converted coralline hydroxyapatites have been widely used in biomedical application as orbital implant and bone graft substitute. The aim of this study was to characterize the physical and chemical properties of various corals found in Bidong Island and determines their potential for development of bone graft substitute. Five species of coral which is commonly found in Bidong Island, Terengganu was collected and identified. The physical properties of corals such as density and porosity were determined using the Archimedes Principle, whereas a mechanical strength was determined using a universal testing machine. The structure of corals such as pore sizes and shape, distribution and pore connectivity was observed using Scanning Electron Microscope (SEM). Chemical properties of corals were characterized using X-ray diffraction (XRD), and energy dispersive x-ray (SEM-EDX). Five species of coral were identified as Leptoria, Porites, Platygyra, Acropora and Pocillopora. The densities of corals range from 2.00 to 19.00 g/cm3 while the porosity range from 15 to 60%. The corals structure consists of interconnected open pores with mean pore sizes in range of 100 to 600μm. Their compressive strengths are in the range of 4.92 to 27 MPa, which is higher than the reported strength for cancellous bone. SEM-EDX analysis shows the elements calcium carbonate (C, O and Ca) found in Platygyra. This result was supported by XRD analysis, which shows the calcium carbonate phase in form of aragonite presence in Platygyra. Aragonite phase was suitable for transforming coral to hydroxyapatite via hydrothermal treatment. Based on this finding, coral species in Bidong Island, Terengganu has been great potential to be used as bone graft substitutes.
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Zapalski, Mikołaj K., Andrew H. Baird, Tom Bridge, Michał Jakubowicz, and James Daniell. "Unusual shallow water Devonian coral community from Queensland and its recent analogues from the inshore Great Barrier Reef." Coral Reefs 40, no. 2 (February 4, 2021): 417–31. http://dx.doi.org/10.1007/s00338-020-02048-9.
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AbstractPalaeozoic coral communities were dominated by two extinct coral groups: Tabulata and Rugosa. Whilst they are not closely related to modern Scleractinia, they are morphologically convergent, displaying many morphological characters that allow comparisons between recent and ancient coral reef communities. The extensive shallow-water reef communities of the Devonian were generally dominated by stromatoporoid sponges, with corals occupying deeper environments. Here, we describe an unusual, shallow water coral reef community from the Middle Devonian (Givetian, approx. 385 Ma) of the Fanning River area, Queensland, Australia. The coral community is dominated by tabulate corals, but also includes solitary and occasionally colonial rugose corals. Tabulate corals most commonly exhibit foliose and massive morphologies, but encrusting and branching growth forms also occur. The depositional environment was characterized by a shallow water depth, moderate hydrodynamic energy, high sedimentation rate, and high turbidity. Since these environmental factors influence the morphological composition of modern coral communities, we hypothesize that similar environments may result in morphologically equivalent coral assemblages throughout the Phanerozoic. To test this idea, we qualitatively compare the Fanning River reefs with modern scleractinian coral assemblages in a similar environmental setting at Magnetic Island. Both reefs are located in a shallow water less than 10 m deep, with high sediment flux, moderate wave energy, and generally high turbidity. Like Fanning River, Magnetic Island coral communities are dominated by foliose morphologies, with contributions from massive and branching forms. The Fanning River reef, together with previously identified Silurian and Devonian mesophotic coral ecosystems, suggest that Palaeozoic coral assemblages may share many functional characteristics with modern scleractinian reefs in similar environments. Therefore, the geological record of inshore, high turbidity-adapted coral communities can be traced back as far as 385 Ma.
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Eagleson, Ryan G., John S. Lumsden, Lorenzo Álvarez-Filip, Christophe M. Herbinger, and Ryan A. Horricks. "Coverage Increases of Porites astreoides in Grenada Determined by Shifts in Size-Frequency Distribution." Diversity 13, no. 7 (June 24, 2021): 288. http://dx.doi.org/10.3390/d13070288.
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Despite coral community collapse, the mustard hill coral (Porites astreoides) is a species currently experiencing success throughout the Caribbean. The inshore reefs of Grenada were selected to study the influence of benthic factors on the abundance, size, and coverage of P. astreoides colonies. Surveys of reef communities along established 30 m transects were conducted at eight sites in 2014 and 2017 using a 0.5 m² quadrat. Coral Point Count was used to annotate the images, estimating the coverage of scleractinian corals, sponges, algae, and benthic substrates. Coverage, size, and abundance of P. astreoides colonies were quantified using the area measurement tool in ImageJ standardized against the quadrats. There were significant differences in benthic community assemblages between islands, selected sites, and between years. From 2014 to 2017 there was a significant decrease in the mean abundance of P. astreoides colonies and significant increases in mean colony size and coverage. The presence of P. astreoides colonies was significantly correlated with: rubble (−), sand (−); pavement (+); macroalgae (−); coralline algae (+); sponges (varying response); gorgonians (−); massive corals (+); and branching corals (−). P. astreoides follows similar recruitment patterns as other scleractinian corals. Observed changes in P. astreoides populations appear to indicate a recovery event following a disturbance, potentially tropical storm Chantal in 2013.
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Apprill, A., H. Holm, AE Santoro, C. Becker, M. Neave, K. Hughen, A. Richards Donà, et al. "Microbial ecology of coral-dominated reefs in the Federated States of Micronesia." Aquatic Microbial Ecology 86 (April 22, 2021): 115–36. http://dx.doi.org/10.3354/ame01961.
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Microorganisms are central to the functioning of coral reef ecosystems, but their dynamics are unstudied on most reefs. We examined the microbial ecology of shallow reefs within the Federated States of Micronesia. We surveyed 20 reefs surrounding 7 islands and atolls (Yap, Woleai, Olimarao, Kosrae, Kapingamarangi, Nukuoro, and Pohnpei), spanning 875053 km2. On the reefs, we found consistently higher coral coverage (mean ± SD = 36.9 ± 22.2%; max 77%) compared to macroalgae coverage (15.2 ± 15.5%; max 58%), and low abundances of fish. Reef waters had low inorganic nutrient concentrations and were dominated by Synechococcus, Prochlorococcus, and SAR11 bacteria. The richness of bacterial and archaeal communities was significantly related to interactions between island/atoll and depth. High coral coverage on reefs was linked to higher relative abundances of Flavobacteriaceae, Leisingera, Owenweeksia, Vibrio, and the OM27 clade, as well as other heterotrophic bacterial groups, consistent with communities residing in waters near corals and within coral mucus. Microbial community structure at reef depth was significantly correlated with geographic distance, suggesting that island biogeography influences reef microbial communities. Reefs at Kosrae Island, which hosted the highest coral abundance and diversity, were unique compared to other locations; seawater from Kosrae reefs had the lowest organic carbon (59.8-67.9 µM), highest organic nitrogen (4.5-5.3 µM), and harbored consistent microbial communities (>85% similar), which were dominated by heterotrophic cells. This study suggests that the reef-water microbial ecology on Micronesian reefs is influenced by the density and diversity of corals as well as other biogeographical features.
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GUMBIRA, RADEN WILLY WIGUNA, FITRI RIZKIA, TRI DEWI KUSUMANINGRUM PRIBADI, and MUHAMMAD SYAEFUL HIDAYAT. "Threat of blast fishing on coral diversity in Peucang Island, Ujung Kulon National Park, Indonesia." Ocean Life 1, no. 1 (May 16, 2017): 26–31. http://dx.doi.org/10.13057/oceanlife/o010105.
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Gumbira RWW, Rizkia F, Pribadi TDK, Hidayat MS. 2017. Threat of blast fishing on coral diversity in Peucang Island National Park, Indonesia. Ocean Life 1: 26-31. As a maritime country with high biodiversity, the health of Indonesian coral reefs is of high concern. Coral reef ecosystems are friable, and mortality occurs relatively quickly after disturbance, not only by nature but also by human activities such as fish bombing. Fish bombing is a big issue that has always threatened coral reefs, including in Peucang Island, part of Ujung Kulon National Park, a place that is protected by law to preserve its natural diversity. A study on coral coverage was conducted to observe the condition of corals and related biota in a coral reef ecosystem. Data was collected using Point Intercept Transect method in 2m and 8m depths. The results showed that coral coverage in 8-meter depth is only 44.02 percent of the live coral in 2-meter depth. The reduction in the value of Diversity Indices, Dominance Indices as well as the Evenness Index in all study sites led to low diversity, with no dominance by a particular species at any of the study sites. The results also showed that corals are well distributed in both depths. Over the past three years, the damage to corals in Peucang Island had generally increased by 0.7 percent due to fish bombing activities.
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Smith, Jennifer E., Rusty Brainard, Amanda Carter, Saray Grillo, Clinton Edwards, Jill Harris, Levi Lewis, et al. "Re-evaluating the health of coral reef communities: baselines and evidence for human impacts across the central Pacific." Proceedings of the Royal Society B: Biological Sciences 283, no. 1822 (January 13, 2016): 20151985. http://dx.doi.org/10.1098/rspb.2015.1985.
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Numerous studies have documented declines in the abundance of reef-building corals over the last several decades and in some but not all cases, phase shifts to dominance by macroalgae have occurred. These assessments, however, often ignore the remainder of the benthos and thus provide limited information on the present-day structure and function of coral reef communities. Here, using an unprecedentedly large dataset collected within the last 10 years across 56 islands spanning five archipelagos in the central Pacific, we examine how benthic reef communities differ in the presence and absence of human populations. Using islands as replicates, we examine whether benthic community structure is associated with human habitation within and among archipelagos and across latitude. While there was no evidence for coral to macroalgal phase shifts across our dataset we did find that the majority of reefs on inhabited islands were dominated by fleshy non-reef-building organisms (turf algae, fleshy macroalgae and non-calcifying invertebrates). By contrast, benthic communities from uninhabited islands were more variable but in general supported more calcifiers and active reef builders (stony corals and crustose coralline algae). Our results suggest that cumulative human impacts across the central Pacific may be causing a reduction in the abundance of reef builders resulting in island scale phase shifts to dominance by fleshy organisms.
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Rooper, Christopher N., Rachel Wilborn, Pamela Goddard, Kresimir Williams, Richard Towler, and Gerald R. Hoff. "Validation of deep-sea coral and sponge distribution models in the Aleutian Islands, Alaska." ICES Journal of Marine Science 75, no. 1 (May 26, 2017): 199–209. http://dx.doi.org/10.1093/icesjms/fsx087.
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Abstract Spatial management of vulnerable benthic ecosystem components such as deep-sea corals and sponges requires adequate maps of their distribution. These maps are often based on statistical models of survey data. The objective of this project was to validate the predictions of existing presence or absence and abundance models of deep-sea corals and sponges in the Aleutian Islands that were based on bottom trawl survey data. Model validation was conducted by comparing bottom trawl survey model predictions to the observations of an in situ camera survey conducted at randomly selected locations. The measures of goodness of fit (area-under-the-receiver-operator-curve, AUC) for the bottom trawl survey model predictions of camera survey observations ranged from 0.59 to 0.77 (for sponges and coral, respectively) and indicated that the bottom trawl survey models predicted the probability of presence for corals accurately across the Aleutian Islands. The bottom trawl survey models explained as little as 3% of the variability in Stylasteridae density and up to 17% of the variability in coral density. These results indicate that models of deep-sea coral distributions based on presence and absence data from bottom trawl surveys can be accurate and can provide useful information for spatial management of these vulnerable taxa. However, for some other taxa, such as sponges, care should be taken interpreting the results of bottom trawl survey models. An interesting finding of this study was that the residuals from the bottom trawl survey model-camera density relationships were negative in areas that remained open to fishing after 2005, possibly indicating an effect of continued bottom trawling on the abundance of corals in these areas. This study highlights the importance of validating models of species distribution using independent surveys, so that the results can be used with confidence to support decision-making processes.
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Zhao, Meixia, Kefu Yu, Qi Shi, Hongqiang Yang, Bernhard Riegl, Qiaomin Zhang, Hongqiang Yan, Tianran Chen, Guohui Liu, and Ziyun Lin. "The coral communities of Yongle atoll: status, threats and conservation significance for coral reefs in South China Sea." Marine and Freshwater Research 67, no. 12 (2016): 1888. http://dx.doi.org/10.1071/mf15110.
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Xisha Islands are in the central South China Sea and form one of the four large island groups in this region. They include more than 40 islands, reefs and cays, and have considerable ecological and biodiversity value, both intrinsically and as a source of larvae for coastal ecosystems throughout the South China Sea. Yongle atoll is the biggest and one of the most important atolls in the Xisha Islands. The detailed surveys of the marine habitats in the Yongle atoll were conducted from June to July 2013. This baseline survey revealed coral communities in a relatively healthy condition. Mean coral cover of different geomorphic habitats varied from 2 to 29%. Branching corals were most important, followed by encrusting and massive growth forms (48, 29 and 17% of coral cover). Pocillopora (29% of total cover in line transects), Porites (19%), Acropora (17%) and Montipora (16%) were the four dominant genera. Communities differentiated into four clusters, namely, lower reef slope, upper reef slope, outer reef flat, and inner reef flat and lagoon slope. This baseline investigation highlighted the ecological value of these reefs. Destructive fishing and overfishing are presently the most serious threats for these coral reefs. They should receive much more scientific and conservation attention.
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Sumadhiharga, Ono Kurnaen. "A PRELIMINARY STUDY ON THE ECOLOGY OF THE CORAL REEF OF POMBO ISLAND." Marine Research in Indonesia 17 (May 10, 2018): 29–49. http://dx.doi.org/10.14203/mri.v17i0.349.
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A preliminary study on the ecology of the coral reef of Pombo Island was carried out in 1975. Pombo Island has a characteristic of an atoll and is considered a good habitat for coral and fish, including live-bait fish of commercial importance, Spratelloides delicatulus. Non-planktonic organisms collected consist of 39 species of corals, 56 species of molluscs, 17 species of echinoderms, 130 species of fishes and a number of crustacean species.Some ecological factors such as bottom condition, turbidity, temperatures, light intensity, and freshwater dilution are described. Population and distribution of corals and coral fishes are discussed.
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George, Emma E., James A. Mullinix, Fanwei Meng, Barbara A. Bailey, Clinton Edwards, Ben Felts, Andreas F. Haas, et al. "Space-filling and benthic competition on coral reefs." PeerJ 9 (June 29, 2021): e11213. http://dx.doi.org/10.7717/peerj.11213.
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Reef-building corals are ecosystem engineers that compete with other benthic organisms for space and resources. Corals harvest energy through their surface by photosynthesis and heterotrophic feeding, and they divert part of this energy to defend their outer colony perimeter against competitors. Here, we hypothesized that corals with a larger space-filling surface and smaller perimeters increase energy gain while reducing the exposure to competitors. This predicted an association between these two geometric properties of corals and the competitive outcome against other benthic organisms. To test the prediction, fifty coral colonies from the Caribbean island of Curaçao were rendered using digital 3D and 2D reconstructions. The surface areas, perimeters, box-counting dimensions (as a proxy of surface and perimeter space-filling), and other geometric properties were extracted and analyzed with respect to the percentage of the perimeter losing or winning against competitors based on the coral tissue apparent growth or damage. The increase in surface space-filling dimension was the only significant single indicator of coral winning outcomes, but the combination of surface space-filling dimension with perimeter length increased the statistical prediction of coral competition outcomes. Corals with larger surface space-filling dimensions (Ds > 2) and smaller perimeters displayed more winning outcomes, confirming the initial hypothesis. We propose that the space-filling property of coral surfaces complemented with other proxies of coral competitiveness, such as life history traits, will provide a more accurate quantitative characterization of coral competition outcomes on coral reefs. This framework also applies to other organisms or ecological systems that rely on complex surfaces to obtain energy for competition.