Review: Formation and Metabolic Function of Coral Rubble Biofilms in the Reef Ecosystem

When coral dies, their calcareous skeletons constitute coral rubble in conjunction with the cementing activity of coralline algae and bacteria, creating a secondary reef structure which takes from years to decades to form. Healthy coral reefs differ from coral—rubble dominated reefs in microbial taxonomic composition and metabolic functional roles. The metabolisms of healthy reefs are dominated by autotrophic pathways, where carbon and nitrogen fixation dominate, while the metabolism of rubble—dominated reefs predominate in degradation of organic matter. Nitrogen fixation is 3 orders of magnitude lower in rubble—dominated reefs than in healthy reefs. Coral—rubble harbors a vast diversity of microbes that can precipitate carbonate through coupling several metabolic processes including photosynthesis, ureolysis, ammonification, denitrification, sulfate reduction, methane oxidation, and anaerobic sulfide oxidation. All these metabolic processes were found in rubble microbial communities, but ammonification and sulfate reduction were most prevalent. Anthropogenic and non—anthropogenic perturbations of healthy coral reefs in the past decades have led to the prevalence of rubble—dominated reefs in areas of the Caribbean where the ecological and functional shifts of the community still need further study.

Kondisi Barang di Pulau Baranglompo dan Bone Batang Berdasarkan Tabel Kesehatan Karang

The structure of wing scales in four species of papilionid butterflies were The research about the condition of coral reefs in Baranglompo and Bone Batang island was conducted in January to April 2016 based on “Coralwatch” table. The aim of this study was to determine health condition of coral reefs in Baranglompo and Bone Batang island. The data was obtained in the south, west, and north at a depth of 3 meters and 10 meter using Line Intercept Transect (LIT) method along 100 meters of both islands. The health condition of coral reefs was obtained from four coral colony types specifically Branching, Massive, Tabulate, and Soft coral using Coralwatch method. The results of this study showed that the health condition of coral reefs in Baranglompo and Bone Batang islands was still relatively equal. At a depth of 3 meters, the most healthy coral colony was dominated by branching corals while at a depth of 10 meters dominated by massive corals. However, the average value of coral colors indicating coral condition showed that the health condition of coral reefs in Baranglompo was higher than that in Bone Batang island. High anthropogenic impacts were observed by the trash commonly found in Baranglompo island, many fish bombings also found in Bone Batang island. This study recommend that the health condition of coral reefs in Baranglompo island was greater than that in Bone Batang island.

A place for taxonomic profiling in the study of the coral prokaryotic microbiome

ABSTRACT The enormous variability in richness, abundance and diversity of unknown bacterial organisms inhabiting the coral microbiome have challenged our understanding of their functional contribution to coral health. Identifying the attributes of the healthy meta-organism is paramount for contemporary approaches aiming to manipulate dysbiotic stages of the coral microbiome. This review evaluates the current knowledge on the structure and mechanisms driving bacterial communities in the coral microbiome and discusses two topics requiring further research to define the healthy coral microbiome. (i) We examine the necessity to establish microbial baselines to understand the spatial and temporal dynamics of the healthy coral microbiome and summarise conceptual and logistic challenges to consider in the design of these baselines. (ii) We propose potential mechanical, physical and chemical mechanisms driving bacterial distribution within coral compartments and suggest experiments to test them. Finally, we highlight aspects of the use of 16S amplicon sequencing requiring standardization and discuss its contribution to other multi-omics approaches.

Spatial analysis of coral reefs and its degradation patterns in Bunaken National Park

This article will analyze the spatial pattern as well as the degradation pattern of the coral reefs in the Bunaken National Park. Bunaken National Park is a marine national park located in the Province of North Sulawesi; the park was built as means of conservation as well as providing a region for tourism. The national park contains a different type of marine and land ecosystem, one of the many types of the ecosystem that are in the national park is coral reefs. Coral reefs in Bunaken National Park provides different kinds of function and benefits whether for the marine habitats that live around the ecosystem, as well as for the local people who live in the islands of the national park. Remote sensing could be used as a tool to identify the spatial pattern and the type of ecosystem that habits inside shallow sea water. The main issue with this method is that the research cannot be conduct directly to identify which type of ecosystem specifically (such as coral reefs, seagrass, etc.), as well as its condition. Therefore, data collecting is necessary to observe and identify the ecosystem and its condition specifically. This study uses satellite image from Landsat 8 OLI as the main secondary data to be processed. The satellite image will be processed by using an algorithm of shallow water analysis that was introduced by Lyzenga in 1981. Since data verification and data observation is needed for this study, the research observes the pattern of the different type of ecosystem and its condition that spreads around Bunaken National Park. The verification and observation process was done by GPS, there were 250 different samples from the data that were collected around the Bunaken National Park. The sample that was collected in the study area will be used to classify the satellite image that has been processed by shallow water algorithm, on which could identify: seagrass, bleached coral reefs, deceased coral reefs, and healthy coral reefs around the national park. The results of this study show the spatial pattern of the coral reefs is located usually around the islands in the Bunaken National Park. The results show that the coral reefs are mostly located around the islands in the National Park. The map results show that the healthy coral reefs are usually located in the outermost layer around the shallow water ecosystem. The bleached reefs are usually located in the middle section of the shallow water, between the healthy coral and the islands itself. Most of the reefs that died and bleached are in the southwest of Bunaken Island, and the northwest of Nain Island.

Life cycles of coral-associated-viruses related to diffrent health states collected in Hang Rai - Ninh Thuan, Vietnam

In recent years, coral associated viruses could play primal role in protecting coral health, yet their ecological traits are poorly investigated. In this study, the abundance and life cycles (lysogeny and lytic) of viruses associated with contrasted coral health states (healthy and bleached) were studied and compared. In addition, the density of bacteria and Symbiodium were also be determined by epifluorescence microscopy. The results showed that viral abundance increased 1.2 times and bacterial abundance decreased 0.6 times in healthy corals compared to bleached ones. The number of Symbiodinium significantly reduced 5.6 times in bleached corals compared to healthy corals. One of the most important results in this study was the coexistence of the both lysogenic and lytic viruses in healthy coral. The fraction of lysogenic bacteria was 2 times higher in healthy corals than in bleached ones. Healthy corals carried 3.5-fold more viral production than the diseased ones. Overall, the results showed that, in healthy state, corals might be a favorable environment for viral infection, promoting the development of both temperate and virulent phages. This coexistence might be crucial for coral viability through the complex links with their coral-associated bacterial hosts.

Intra-colony disease progression induces fragmentation of coral fluorescent pigments

As disease spreads through living coral, it can induce changes in the distribution of coral’s naturally fluorescent pigments, making fluorescence a potentially powerful non-invasive intrinsic marker of coral disease. Here, we show the usefulness of live-imaging laser scanning confocal microscopy to investigate coral health state. We demonstrate that the Hawaiian coral Montipora capitata consistently emits cyan and red fluorescence across a depth gradient in reef habitats, but the micro-scale spatial distribution of those pigments differ between healthy coral and coral affected by a tissue loss disease. Naturally diseased and laboratory infected coral systematically exhibited fragmented fluorescent pigments adjacent to the disease front as indicated by several measures of landscape structure (e.g., number of patches) relative to healthy coral. Histology results supported these findings. Pigment fragmentation indicates a disruption in coral tissue that likely impedes translocation of energy within a colony. The area of fragmented fluorescent pigments in diseased coral extended 3.03 mm ± 1.80 mm adjacent to the disease front, indicating pathogenesis was highly localized rather than systemic. Our study demonstrates that coral fluorescence can be used as a proxy for coral health state, and, such patterns may help refine hypotheses about modes of pathogenesis.

Modelling environmental drivers of black band disease outbreaks in populations of foliose corals in the genus Montipora

Seawater temperature anomalies associated with warming climate have been linked to increases in coral disease outbreaks that have contributed to coral reef declines globally. However, little is known about how seasonal scale variations in environmental factors influence disease dynamics at the level of individual coral colonies. In this study, we applied a multi-state Markov model (MSM) to investigate the dynamics of black band disease (BBD) developing from apparently healthy corals and/or a precursor-stage, termed ‘cyanobacterial patches’ (CP), in relation to seasonal variation in light and seawater temperature at two reef sites around Pelorus Island in the central sector of the Great Barrier Reef. The model predicted that the proportion of colonies transitioning from BBD to Healthy states within three months was approximately 57%, but 5.6% of BBD cases resulted in whole colony mortality. According to our modelling, healthy coral colonies were more susceptible to BBD during summer months when light levels were at their maxima and seawater temperatures were either rising or at their maxima. In contrast, CP mostly occurred during spring, when both light and seawater temperatures were rising. This suggests that environmental drivers for healthy coral colonies transitioning into a CP state are different from those driving transitions into BBD. Our model predicts that (1) the transition from healthy to CP state is best explained by increasing light, (2) the transition between Healthy to BBD occurs more frequently from early to late summer, (3) 20% of CP infected corals developed BBD, although light and temperature appeared to have limited impact on this state transition, and (4) the number of transitions from Healthy to BBD differed significantly between the two study sites, potentially reflecting differences in localised wave action regimes.

Modelling environmental drivers of black band disease outbreaks in populations of foliose corals in the genus Montipora

Seawater temperature anomalies associated with warming climate have been linked to increases in coral disease outbreaks that have contributed to coral reef declines globally. However, little is known about how seasonal scale variations in environmental factors influence disease dynamics at the level of individual coral colonies. In this study, we applied a multi-state Markov model (MSM) to investigate the dynamics of black band disease (BBD) developing from apparently healthy corals and/or a precursor-stage, termed ‘cyanobacterial patches’ (CP), in relation to seasonal variation in light and seawater temperature at two reef sites around Pelorus Island in the central sector of the Great Barrier Reef. The model predicted returning rate from BBD to Healthy in three months was approximately 57%, but 5.6% of BBD cases resulted in whole colony mortality. Healthy coral colonies were more susceptible to BBD during summer months when light levels were at their maxima and seawater temperatures were either rising or at their maxima. In contrast, CP mostly occurred during spring, when both light and seawater temperatures were rising. This suggests that environmental drivers for healthy coral colonies transitioning into a CP state are different from those driving transitions into BBD. Our model predicts that (1) the transition from healthy to CP state is best explained by rising light, (2) the transition between healthy to BBD occurs more frequently from early to late summer, (3) 20% of CP infected corals developed BBD, although light and temperature appeared to have limited impact on this state transition, and (4) the number of transitions from healthy to BBD differed significantly between the two study sites, potentially reflecting differences in localised wave action regimes.

Modelling environmental drivers of black band disease outbreaks in populations of foliose corals in the genus Montipora

Seawater temperature anomalies associated with warming climate have been linked to increases in coral disease outbreaks that have contributed to coral reef declines globally. However, little is known about how seasonal scale variations in environmental factors influence disease dynamics at the level of individual coral colonies. In this study, we applied a multi-state Markov model (MSM) to investigate the dynamics of black band disease (BBD) developing from apparently healthy corals and/or a precursor-stage, termed ‘cyanobacterial patches’ (CP), in relation to seasonal variation in light and seawater temperature at two reef sites around Pelorus Island in the central sector of the Great Barrier Reef. The model predicted returning rate from BBD to Healthy in three months was approximately 57%, but 5.6% of BBD cases resulted in whole colony mortality. Healthy coral colonies were more susceptible to BBD during summer months when light levels were at their maxima and seawater temperatures were either rising or at their maxima. In contrast, CP mostly occurred during spring, when both light and seawater temperatures were rising. This suggests that environmental drivers for healthy coral colonies transitioning into a CP state are different from those driving transitions into BBD. Our model predicts that (1) the transition from healthy to CP state is best explained by rising light, (2) the transition between healthy to BBD occurs more frequently from early to late summer, (3) 20% of CP infected corals developed BBD, although light and temperature appeared to have limited impact on this state transition, and (4) the number of transitions from healthy to BBD differed significantly between the two study sites, potentially reflecting differences in localised wave action regimes.

Spatial Pattern of Water Quality on Coral Reef Area Around Kaledupa Island

Healthy coral reefs depends on the quality of the waters , so that research and monitoring of water quality becomes important. This research attempt to asses marine waters quality at kaledupa island and it’ s surrounding waters on October and November 2014. 33 In-situ samples were collected using multiparameters tool purposively which are categorized into physical parameters (temperature, turbidity and clarity), and chemical parameters (DO, salinity and pH). Waters quality defined by STORET method based on Ministry of Living Environment decree number 115 year of 2003. Analysis geographically has been conducted to describe distribution of waters quality spatially. The result shows that Kaledupa waters has sustain slightly pollution, especially on DO, turbidity, temperature and salinity parameters which have deviated from standard values. The light pollution in Kaledupa waters is suspected caused by the entry of abundance organic matter and shallow bathymetry.