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Marine Protected Areas (MPAs) are widely used to protect at-risk ecosystems. This study employed a combined method to quantify the protection performance on coral reef habitats, integrating coral morphology and topographic relief in the rugosity index. In the Weizhou Island reef in the northern South China Sea, after six years of protection, the no-take areas (NTAs) hosted a greater live coral cover (11.7%) compared to the no-protection areas (NPAs, 6.9%), but had a lower rugosity (1.17) than both the NPAs and the habitat protection areas, suggesting that while MPAs enhance coral cover, their benefits for habitat structural complexity may remain insignificant in the short term (six years). In the NTAs, the contribution of live corals to habitat complexity (28.3%) was lower than that of rubbles (34.4%). Moreover, slow-growing massive corals (e.g., Porites lutea), which usually have low rugosity, contributed a larger portion (up to 20%) to habitat complexity. In contrast, fast-growing, structural complex arborescent corals (e.g., Acropora pruinosa) had a limited contribution (2.3%). Foliose corals, which dominated the coral community also have lower rugosity (1.2 ~ 1.3) compared to massive and arborescent corals, presumably due to phenotypic plasticity in response to specific environmental conditions. This study suggests that prioritizing coral species composition, especially corals with high rugosity, is important for effective reef framework reconstruction. [ABSTRACT FROM AUTHOR]

Coral reefs off the coast of the Republic of Sudan are still considered to be among the most pristine reefs in the central Red Sea. The complex coastal fringing reefs, offshore banks, and shoals of Dungonab Bay in the north and Sanganeb atoll situated further to the south, about 23 km off the Sudanese mainland coast, were inscribed on the UNESCO World Heritage List in 2016. Due to their remote location and limited access, monitoring of the status of the reefs has been sporadic. Here, we present the results of a repeated large area photomosaic survey (5 m × 5 m plots) on the Sanganeb atoll, first established and surveyed in 1980, and revisited in 1991 and most recently in 2019. The 2019 survey recovered and reinstated the four original monitoring plots. Evaluation of photographic and video records from one photomosaic plot on the seaward slope of the atoll revealed general continuity of the overall community structure and composition over 39 years. Individual colonies of Echinopora gemmacea and Lobophyllia erythraea were recorded in the exact same positions as in the 1980 and 1991 plots. The genera Acropora and Pocillopora remain dominant, although in altered proportions. Shifts in composition were detected at the species level (e.g., increase in Pocillopora verrucosa, Stylophora pistillata, Acropora hemprichii, Dipsastraea pallida, and Echinopora gemmacea, decrease in Acropora cytherea and A. superba), in addition to changes in the extent of uncolonized substrate (e.g., increase from 43.9% in 1980 to 52.2% in 2019), and other scleractinian, hydrozoan, and soft coral living cover. While the temporal resolution only includes three sampling events over 39 years (1980, 1991, 2019), this study presents one of the longest time series of benthic community surveys available for the entire Red Sea. A semi-quantitative estimate of vertical reef growth in the studied test plot indicates a reduction in net accretion rates of more than 80%, from 2.27 to 2.72 cm/yr between 1980 and 1991 to 0.28–0.42 cm/yr between 1991 and 2019. We carefully conclude that the changes observed in the coral community in the plot in 2019 (Acropora–Pocillopora shift, increase in Montipora and calcareous algae) are representative of impacts at the community level, including rising sea surface temperatures and recent bleaching events. [ABSTRACT FROM AUTHOR]

The high diversity and biomass of organisms associated with coral communities depend directly on the maintenance or changes in the benthic composition. Over a decade, we evaluated the spatiotemporal variation in the benthic structure and composition of an insular coral community in the Northeastern Tropical Pacific. Our results show that local conditions drive spatiotemporal differences, and benthic organisms such as sponges, crustose coralline algae, octocorals, and hydrocorals all increased in abundance (cover) in response to negative thermal anomalies caused by the 2010–2011 La Niña event. In contrast, abnormally high temperatures, such as those recorded during the 2015–2016 El Niño Southern Oscillation (ENSO) event, explain the loss of scleractinian corals and crustose coralline algae coverage, which reduced the benthic groups' richness (BGR), diversity (H'BG), and evenness (J'BG), with evidence of a consequent decrease in ecosystem function recorded the following year. Our analysis also showed that sites with high habitat heterogeneity harbored higher average BRG and H'BG values and were less affected by environmental fluctuations than sites with high live scleractinian coral cover and lower BRG and H'BG values. Therefore, the benthic structure was impacted differently by the same perturbation, and changes in the benthic community composition affected the groups associated with the community and ecological functions. More importantly, regional stressors such as the ENSO event caused only temporary changes in the benthic community structure, demonstrating the high resilience of the community to annual and interannual stressors. [ABSTRACT FROM AUTHOR]

Extensive coral bleaching events can result in catastrophic degradation of coral reefs and reorganization of coral communities. In the present study, we analyzed the spatial differences in coral bleaching and possible reasons of large-scale coral bleaching, based on the results of a survey carried out in the northern South China Sea in 2020. In addition, we have continuously monitored the sea surface temperature (SST) of the northernmost Weizhou Island for more than six years. The living coral cover at Weizhou Island (W), Xuwen Nature Reserve (X), and Haihua Island (H) was relatively high at 24.6% ± 4.8%, 12.1% ± 3.8%, and 8.1% ± 2.6%, respectively, whereas their bleaching rates were 9.7% ± 2.6%, 9.7% ± 3.3%, and 6.9% ± 2.1%, respectively. Among them, the living coral cover of W was significantly different from those of X and H, whereas the bleaching rate was not significantly different among the three areas. In all three areas, the massive and encrusting corals predominate and exhibit relatively high bleaching rates, with Porites lutea and Bernardpora stutchburyi being the dominant species. In addition, the temperature monitoring results of Weizhou Island for six consecutive years showed that the critical SST of coral bleaching was 31.5 ℃. The monitoring results also showed that the average SST of Weizhou Island was 32.1 ℃, exceeding 32 ℃ in July 2020 for up to 533 h. The longest continuous time when the SST exceeded 32 ℃ was 97 h. These findings indicated that the coral bleaching event that occurred in the Beibu Gulf during 2020 was a large-scale and high-temperature transient event that presented a relatively homogeneous threat to the coral communities. We inferred that this sudden heat stress event was caused by the enclosed tidal current in the Beibu Gulf, which prevented the southern upwelling from reaching the north, as well as by the inability of the SST to decrease without rainfall caused by typhoon cyclones. Our findings suggested that abnormal heat waves can result in coral bleaching at high latitudes and even coral reef degradation. Furthermore, our study provides a new perspective for investigating the self-recovery and reorganization of coral communities following accumulated coral bleaching. [ABSTRACT FROM AUTHOR]

Simple Summary: The Xuwen coral reef, as a potential refuge for corals to adapt to high-temperature migration, is an ideal "laboratory" to determine the impact of human activities on coral reef ecology in the northern South China Sea (NSCS). Global warming, coastal eutrophication and the decrease in herbivores has influenced coral reef degradation; compared with human activities, global climate change is the stronger influence on coral reef degradation on a large scale. For the Xuwen coral reef, which is in the coastal zone, anthropogenic stressors are more significant to the rapid degradation of its coral reef ecosystems. Under these circumstances, more evidence is required to understand the response of high-latitude reefs under natural and anthropogenic stresses. In this study, we investigated the ecological features of the scleractinian coral assemblage and their correlation with environmental factors on the Xuwen coral reef in 2020. Based on the data acquired by investigation and the implementation of statistical analysis methods, potential environmental conditions favoring coral communities in Xuwen were summarized. These results of the survey are expected to provide a basis for bridging the gap between economic development and sustainable management. Taking the coral communities of the Xuwen coral reef in 2020 as the research object, we analyzed the species composition, diversity, and interspecific Spearman correlation of the scleractinian coral communities, investigated the features and spatial distribution of the scleractinian coral community, and discussed the correlation between the community composition and environmental factors to identify the affecting factors and their sources. These results showed that (1) compared with the survey in 2004, the coverage of corals in 2020 had significantly decreased, while the dominant genera were still Goniopora and Porites. The coral morphology was massive, and the diversity of the coral community (Shannon–Wiener index, H') was 2.87. The distribution of coral was uneven. The competition among some dominant species of coral was intense. (2) The mass coral bleaching event in the NSCS in August 2020 did not cause severe coral death in the short term on the Xuwen coral reef. (3) The growth of the coral community in 2020 might be greatly affected by high suspended solids and nutrient levels, which were related to the current, mariculture, and coastal erosion. (4) Anthropogenic activities such as coastal aquaculture and fishing were the major factors leading to the reduction in coral coverage on Xuwen coral reef in the past 10 years. [ABSTRACT FROM AUTHOR]

Clipperton, an uninhabited and remote coral atoll from the Eastern Pacific, is an important steppingstone area that harbors a high marine biodiversity. Despite its biogeographic importance, little information on the ecological status of its coral reefs is available from the last decade. Herein, we characterized the benthic coral community and health status among four different shallow reef-zones (North to South) of Clipperton during the Tara Pacific expedition in 2018. The benthic composition (expressed as coverage percentage), as well as occurrence of potential disease-like phenotypes, in particular a pink-spotted coral phenotype was assessed. Average live coral cover on Clipperton reefs was 66% (range 55–85%), differing between sites, with massive Porites and branching Pocillopora corals dominating the benthic community with an average 48% (32–66%), and 15% (3–21%), respectively. While Clipperton reefs exhibited significant live coral cover overall, and no other disease-like phenotypic were observed, the pink-spotted coral phenotype was common, with a higher occurrence in massive corals (Porites 27%, and Pavona 31%). This observation may be related to the combined effects of previously heatwaves, and local inputs of guano-derived nutrients discharged during storms and hurricanes, which may suggest that even highly remote reefs supporting high coral cover can be subject to local and global threats. An alternative hypothesis is that the observation of a healthy reef with high coral cover and high incidence of pink-spotted coral phenotype in the absence of other diseases might reflect potential infection with the parasitic trematode Podocotyloides stenometra. While this hypothesis will have to be confirmed by histological and molecular analysis, it may be possible that larvae of this trematode may experience favorable conditions due to periodic nutrient input frorm the nutrient-rich lagoon or via guano run-off of Clipperton Island. [ABSTRACT FROM AUTHOR]

Coral reefs along the Malacca Straits (MS) are poorly developed mainly due to turbidity and sedimentation. This study describes the health status and community structure of the corals in Cape Rachado, West Coast of Peninsular Malaysia (WCPM), utilizing the Coral Video Transect (CVT) technique. All the survey transects were categorized as ‘fair’ coral conditions (27.39 ± 5.41%-48.56 ± 18.96%) with the reef floor mainly covered by corals and sediment. Twelve families of coral comprised of 25 distinct genera were identified. Coral communities were differentiated into four clusters with each being predominated by Galaxea, Diploastrea, Fungia and Pectinia respectively. Among all, Pectinia is the most spectacular genera and dominated the survey area. Along the MS, Favia, Favites and Porites are commonly found while Porites and Pectinia dominated the reefs. Low coral cover and diversity was recorded in MS as compared to the reefs in the South China Sea (SCS). The most prominent results include changes in the dominant coral from Porites to Pectinia while some species such as Acropora were absent from the study area. Based on the presented data, the reef in the study area was predominantly occupied by sediment and the coral communities were formed by a species with a high tolerance to turbidity and sedimentation. [ABSTRACT FROM AUTHOR]

Climate change and other anthropogenic disturbances are having dramatic impacts on tropical coral reefs and the ecosystem services they provide. Anticipating change in ecosystem services is a pressing challenge that requires understanding how species respond to an environmental change, and how they contribute to ecosystem services. Building on analogous efforts by plant ecologists, we propose a traitbased framework that aims to predict the resistance and recovery of coral ecosystem services against both pulse and press disturbances. The framework involves identifying effect, resistance, and recovery traits across coral species and using these to ascertain how species might (1) contribute to a service, (2) resist disturbance, and (3) recover after the disturbance. By identifying trait functional overlaps and quantifying correlations among the trait types, the framework can yield a better understanding of the potential mechanistic links between community assembly, ecosystem dynamics, and ecosystem functioning. We demonstrate the utility of the framework by applying it to a virtual scenario, implemented via simulation, in which habitat provisioning is the focal ecosystem service, and cyclones and bleaching events are the disturbances of interest. This demonstration required us to assemble an extensive dataset of relevant traits--a process that revealed key gaps in the coral trait database and in our understanding of coral functional ecology. The framework can provide predictive power for the resilience of ecosystem services and can also help identify crucial knowledge gaps, research objectives, and strategies for applying a trait-based approach to advancing coral reef science and conservation. [ABSTRACT FROM AUTHOR]

Coral cover at lower mesophotic depths (particularly >75 m) by zooxanthellate scleractinians is usually very scarce, largely due to the extremely low irradiance levels at these depths. An exception are the Leptoseris communities observed near the Hawaiian islands (Central Pacific) that form dense fields, supporting a broad range of associated organisms. Here, we describe a similar high-cover coral community at lower mesophotic depths, but in the Caribbean. The community was observed on the leeward side of Curaçao (Southern Caribbean) using a manned submersible ( Curasub), and was predominantly composed of plating Agaricia corals and an assemblage of reef fishes. Some of the fish species were known from similar depths at other localities, whereas others obtained new depth records. Future surveys are required to establish the extent of similar high-coral communities around Curaçao, and more broadly in the western Atlantic. [ABSTRACT FROM AUTHOR]

A five-year period (2002-2006) of below-median rainfall followed by a six-year period (2007-2012) of above-median rainfall and seasonal flooding allowed a natural experiment into the effects of runoff on the water quality and subsequent coral community responses in the Whitsunday Islands, Great Barrier Reef (Australia). Satellite-derived water quality estimates of total suspended solids (TSS) and chlorophyll- a (Chl) concentration showed marked seasonal variability that was exaggerated during years with high river discharge. During above-median rainfall years, Chl was aseasonally high for a period of 3 months during the wet season (February-April), while TSS was elevated for four months, extending into the dry season (March-June). Coinciding with these extremes in water quality was a reduction in the abundance and shift in the community composition, of juvenile corals. The incidence of coral disease was at a maximum during the transition from years of below-median to years of above-median river discharge. In contrast to juvenile corals, the cover of larger corals remained stable, although the composition of communities varied along environmental gradients. In combination, these results suggest opportunistic recruitment of corals during periods of relatively low environmental stress with selection for more tolerant species occurring during periods of environmental extremes. [ABSTRACT FROM AUTHOR]

Luhuitou fringing reef, which has been seriously affected by human activities and terrestrial runoff, has degraded quickly in recent decades. However, direct impact by hyperthermal stress has probably been minimal because of the influence of the Qiongdong upwelling in summer. Seawater temperature anomalies in 2010 resulted in mean monthly seawater temperatures in summer to be 1–2°C higher than in the same period of the 3 preceding years. Moderate coral bleaching at Luhuitou fringing reef was observed in the summer of 2010 due to high thermal stress. Montipora was the most susceptible taxon, whereas Galaxea fascicularis and Pocillopora damicornis were among the least susceptible taxa. Mortality of Montipora was 21.7%, whereas for the remaining taxa it was less than 5%. No mortality was observed for tabular Acropora, G. fascicularis, P. damicornis, Favites and Leptoria. Most taxa showed relatively high bleaching in larger colonies compared with that in smaller ones. Juvenile coral colonies showed less bleaching (3%) than adult coral colonies (28%). Our study suggested that although most taxa in the survey area might recover from this moderate coral bleaching episode, coral reproduction in the year following bleaching may be adversely affected. [ABSTRACT FROM AUTHOR]

Observations made on Heron Island reef flat during the 1970s-1990s highlighted the importance of rapid change in hydrodynamics and accommodation space for coral development. Between the 1940s and the 1990s, the minimum reef-flat top water level varied by some tens of centimetres, successively down then up, in rapid response to local engineering works. Coral growth followed sea-level variations and was quantified here for several coral communities using horizontal two-dimensional above water remotely sensed observations. This required seven high spatial resolution aerial photographs and Quickbird satellite images spanning 35 years: 1972, 1979, 1990, 1992, 2002, 2006 and 2007. The coral growth dynamics followed four regimes corresponding to artificially induced changes in sea levels: 1972-1979 (lowest growth rate): no detectable coral development, due to high tidal currents and minimum mean low-tide water level; 1979-1991 (higher growth rate): horizontal coral development promoted by calmer hydrodynamic conditions; 1991-2001(lower growth rate): vertical coral development, induced by increased local sea level by ~12 cm due to construction of new bund walls; 2001-2007 (highest growth rate): horizontal coral development after that vertical growth had become limited by sea level. This unique time-series displays a succession of ecological stage comprising a 'catch-up' dynamic in response to a rapid local sea-level rise in spite of the occurrences of the most severe bleaching events on record (1998, 2002) and the decreasing calcification rates reported in massive corals in the northern part of the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

The article presents a study which focuses on the establishment of a No-take Area (NTA) that could not guarantee the coral communities preservation in Chinwan Inner Bay (CIB) in Penghu, Taiwan. The study uses a study site, rapid assessment techniques, and quantitative surveys modified from ReefCheck methodology. Result found a decline in the living coral from 80.9% in 2001 to 16.3% by 2008 with coral functional group shifting from branching species to massive and columnar species.

The article presents a study on the destruction of hard-coral communities of Qeshm Island, Iran at the side of the Persian Gulf. The study, which covered two main coral sites such as in the south (SHD) and in the southeast (SOEA), conducted laboratory and field surveys to measure sea surface temperature, salinity, and sediments. The study revealed that the low abundance of corals in Persian Gulf is due to several factors including temperature changes, oil pollution, and high sedimentation.

The article focuses on the evaluation of 12 reef sites conservation values in Penghu Islands to promote the first marine protected area (MPA) establishment in Taiwan. Information revealed that the Chinwan Inner Bay (CIB) has the best coral community in the Island with the highest coral cover, species diversity and habitat types. The author inferred the utilization of biological resources and socio-economic factors of CIB were investigated by the intensive field surveys and a several visit-and-poll survey. As a result, the socio-economic data indicated that there was no direct conflict of interests with local communities and the local residents will support the MPA proposals.

In recent decades, coral reefs worldwide have been impacted annually by climate change and anthropogenic impacts. Marine parks are utilized to protect coral reef ecosystems and to ensure it is in sustainable use. In the present study, a 15-year change in coverage and composition of a hard coral community at Dongsha Atoll Marine National Park (DAMNP) was examined from 2005 to 2019. The reef has experienced several disturbances, including 11 typhoons and six coral bleaching events. A 34.39% decline in coral coverage had been recorded over the past 15 years in response to multiple and recurrent natural disturbances. The coral communities and functional ecology of the Dongsha Atoll changed during this period. The average dissimilarities in coral communities ranged from 55.38 to 59.02%. The dramatic decrease in the abundance of branching corals in addition to a slight increase in massive and encrusting corals suggest the habitat has simplified. The degraded coral reef communities represent a low resilience ecosystem, even though the DAMNP has been established. Without effective management, the coral reef ecosystem of the Dongsha Atoll may not persist due to repeated impacts from recurrent disturbances. [ABSTRACT FROM AUTHOR]

A submarine pipeline, constructed in 1997-1998 to provide water to Redang Island, Malaysia traverses an area covered with corals. Biological studies were conducted before and following pipeline constructionto monitor the changes in the biota at selected sites. Benthic invertebrates (including corals) were used as monitoring tools. Student's t-test and one-way ANOVA macroinvertebrates in pre- and post-construction analyses revealed that there was no significant difference in total abundance of sessile periods. Student's t-test revealed that there was a significant difference in mean of live coral coverage during pre and post-construction periods. There was no apparent change in total numbers of macroinvertebrates. Our results suggest only short-term impacts and recovery of the benthic community. [ABSTRACT FROM AUTHOR]