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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]

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]

Sediment load can influence both the population distribution and structures of coral reef communities. We investigated whether coral assemblages on inshore and more turbid reefs differ from those on offshore reefs in the largest coral reefs of the Southwest Atlantic. We compared inshore and offshore reefs (with different turbidity climatologies) in terms of benthic and coral assemblage structures, abundances and individual sizes of coral populations and recruitment patterns. Unexpectedly, the inshore reefs showed higher coral cover and abundance, larger colonies and more recruits. This finding is related to the predominance of sediment-tolerant species on the turbid reefs. In contrast, only Mussismilia braziliensis (main builder of Abrolhos) showed better performance (greater coverage, larger diameter and more recruits) on offshore reefs, apparently behaving as a strong competitor in less turbid environments. These results reinforce the recent thinking of coral reef of turbid environments as resistant ecosystems and potential refuges considering the unnatural increase of sediment supply. • Coastal and heavily turbid coral reefs of Abrolhos have robust coral communities. • These communities flourished due to great performance of sediment-tolerant species. • Coastal reefs show higher coral cover and abundance, larger colonies and more recruits. • Only one coral species performed better in less turbid coral reefs of Abrolhos. • We present a worrying scenario due to the increasing of sediment load worldwide. [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]

S tudies of inshore and offshore coral reef systems usually conclude that there are fundamental differences between them assuming that terrigenous influences diminish with distance from the mainland. However, with few exceptions reefs in Thailand are fringing reefs around continental islands, whether inshore or offshore. We describe patterns in coral community composition along a 70 km transect from the mainland to offshore islands in the southern Andaman Sea. We found that coral assemblages are comprised of two basic types. Differences in coral assemblages were associated with obviously different environmental conditions, including underwater visibility and level of suspended matter, which were not always aligned with distance from the mainland. While reef communities were quite variable between sites, the inshore coral assemblages tended to be characterized by higher numbers of Montipora, Pectinia, Podabacia, and Acropora compared to reefs around offshore islands. Offshore reefs were characterized by a relatively high number of Lobophyllia and Plerogyra colonies. The expected relationship between water quality and sensitive indicator groups like Acropora did not materialize with Acropora and Montipora being more common inshore. While there were strong inshore-offshore reef habitat differences in environmental conditions and reef communities in southern Thailand, they were not consistent with expectations from the literature. [ABSTRACT FROM AUTHOR]

Near-shore coral reefs in northeastern Hainan Island are close to river mouths and aquaculture ponds, and also located at the center of the Qiongdong Upwelling (QDU). However, it is still unclear how terrestrial runoff and upwelling influence the community composition and spatial distribution of the benthos. During three cruises in 2010 and 2011 in Wenchang, northeastern Hainan Island, we determined a subset of environmental parameters in seawater (e.g. temperature, salinity, DO, dissolved inorganic nutrient (DIN), turbidity and transparency) and macroalgal δ 15 N and investigated the benthic communities (e.g. live coral cover, coral species richness, juvenile coral density, macroalgal cover and coverage of calcified algae) by video transect and visual census techniques at 10 stations (i.e. 1S–6D). The results showed that the QDU has influenced the reef waters in Wenchang. In 2011, the upwelling started in early May, peaked in July and disappeared in September and most upwelling events lasted for 1–2 weeks between May and July. The results also demonstrated that the reef water was nutrient enriched. Stations close to the river mouth and aquaculture ponds had higher levels of DIN and a higher percentage of ammonia in DIN, and there was consistently lower live coral cover, juvenile coral density and higher macroalgal cover. At some stations in this study, live coral cover was negatively correlated with macroalgal cover (i.e. 2S–6D). Live coral cover, species richness, and juvenile coral density all increased with the distance away from the river outlet and decreased with the rise of DIN. These results suggest that terrestrial runoff and upwelling stimulate nutrient enrichment, and that overgrowing macroalgae has an important influence on the coral communities in northeastern Hainan Island. [ABSTRACT FROM AUTHOR]

Coral reefs across the southern Arabian Gulf have declined in the past two decades, with extensive loss of formerly Acropora table corals, which are now functionally extinct in nearshore reefs. This study documents the coral community at Sir Bu Nair (SBN), an offshore island buffered by less extreme environmental conditions, which contains the last remaining large stands of Acropora in the southern Gulf. We found that Acropora is a major reef-building coral throughout SBN. Mean coral cover was 27% (range: 6%–49%) across all sites and depths, of which more than half was comprised by Acropora. This varied around the island, with the highest densities to the south and southwest in shallow waters. Our study provides essential information for the management and conservation of these highly valuable and vulnerable corals. • Sir Bu Nair MPA conserves the last Acropora spp. reefs in the southern Arabian Gulf. • We studied coral community changes in depth, location and before and after summer. • Mean coral cover was 27% and corals belonged to 14 genera and 10 families. • We found significant differences in coral assemblages among depths and locations. • This MPA protects a unique coral community with Acropora dominated reefs. [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]

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 world's coral reef ecosystems are steadily being reconfigured by climate change. Lizard Island, on Australia's Great Barrier Reef, offers an opportunity to examine coral reef reassembly following disturbance, as this location has been impacted by consecutive tropical cyclones and consecutive coral bleaching events. Based on repeatedly monitoring the same 349 photoquadrats around Lizard Island over a 5-year period (2016–2021) we revealed that bleaching in 2016 drove a ∼50% reduction in hard coral cover, and a concomitant increase in algal turf cover. From 2018 to 2021, significant increases (>600%) in coral cover were detected on two semi-exposed reefs and were associated with substantial Acropora recruitment. By contrast, fourteen lagoonal and back reefs exhibited virtually no recovery nor Acropora recruitment. Given that the timeframe between disturbances is set to decrease, our results suggest that some recovery is possible immediately after severe cumulative disturbances, although this recovery may be highly spatially heterogenous. [Display omitted] • Recovery of coral reefs following cumulative large-scale disturbances is uncertain. • High-resolution sampling was used to examine benthic dynamics post disturbance. • >600% increases in hard coral cover were detected on semi-exposed reefs. • Recovery was heterogenous and many reefs showed little sign of recovery. • As disturbance events become more frequent, reefs may be typified by algal turfs. [ABSTRACT FROM AUTHOR]

In enhancing coral reef management, identifying the key threats that influence the coral reefs ecosystem needs accurate information on the current knowledge of coral health status and coral communities. This study attempts to update such information by evaluating the data of coral assessment on the reef areas in the southern part of the South China Sea (SCS); the Labuan Marine Park (LMP), Pulau Tioman Marine Park (PTMP), Pulau Kapas Marine Park (PKMP), Pulau Bidong (PB) and Pulau Perhentian Marine Park (PPMP). The Coral Video Transect (CVT) technique was utilised to examine the biotic [live coral (C), algae (ALG) and other invertebrates (OT)] and abiotic [(dead coral (DC), sand, silt and rock (SR)] composition, coral health status and coral communities. The variation of biotic and abiotic components was significantly influenced by 'Area' and 'Tourism Development', which implied that the reefs were influenced by proximity from the mainland and varying human-induced stressors within the site in the survey area. Lower C composition and high cover of ALG, DC and SR can be associated with the decreasing proximity of the reef 'Area' to the mainland and the criteria of 'Tourism Development'. 'Areas' close to the mainland such as PKMP and LMP was mainly dominated by abiotic components. High ALG composition was found in PPMP and some sites in LMP, indicating the high commercial use in the 'Area' have induced the algae colonisation. The reefs nearby the mainland and intense human activities consequently resulting in coral health status with some sites rated as 'poor' condition. PTMP and PB recorded the highest C composition, suggesting distance from the mainland as a factor to PTMP while low human intervention is an attributable factor to PB. No 'poor' sites were found in PTMP and PB, implying that both areas face minimal impact from the local stressors. The coral communities among the areas were dominated by three types of communities; Acropora-Porites-Montipora (LMP), Acropora-Porites (PTMP, PKMP and PPMP) and Acropora-Porites-Fungia (PB), suggesting linkages to the environmental stressor. Conclusively, apart from filling in the information gaps on the current status of the coral reefs, the findings underline the urgent need for systematic Marine Spatial Planning design and adoption to accurately mitigate threats against a more resilient coral reef health in Malaysia. [Display omitted] • Coral Reefs are commonly found close to the coastal area where intense anthropogenic disturbances occurs. • Proximity towards urbanized area and tourism activities influenced the health status of coral reefs. • Sedimentation, nutrient enrichment and tourism activities threatening the coral reefs. • Effective management using Marine Spatial Planning is vital for marine park resilience against human-induced stressors. [ABSTRACT FROM AUTHOR]

Coral reef management is increasingly focused on supporting the resilience of coral communities to increasing and cumulative pressures. The coral index provides a concise summary of coral community resilience that can be efficiently communicated to a range of management and policy stakeholders. We detail the development of the index both as a technical reference for users but also as an example of an approach that could be more generally applied to the reporting of ecosystem resilience. The index is sensitive to acute impacts that are expected when coral communities are exposed to disturbances such as cyclones, bleaching events or crown-of-thorns outbreaks. Importantly, spatial and temporal trends in the index enable the identification of areas and periods of reduced resilience that suggest chronic environmental pressure imposed by runoff. The ability to summarise complex ecological processes into a single index provides an efficient and intuitive tool for the communication of where, when and which pressures are impacting ecosystem resilience. • A multi-indicator index of coral community resilience to inform management. • Acute disturbances drive down coral community condition on the Great Barrier Reef. • Water quality limits coral community resilience on near-shore reefs. [ABSTRACT FROM AUTHOR]

The responses of reef benthic substrata and coral communities to anthropogenic disturbances at the Wuzhizhou Island (WZZ, off the southeast coast of the Hainan Island in the South China Sea) were examined in 2007–2017. A total of 90 scleractinia coral species were recorded at WZZ in 2017. Cluster analysis and ANOSIM analysis of reef benthic composition suggested that WZZ can be divided into the north and south zones with significantly different characteristics. Indeed, anthropogenic disturbance (i.e. , tourism activity and land use) has been intense in the north zone, whereas the south zone has not been as much disturbed. Coral reefs in the north zone suffered from stronger turbidity and nutrient enrichment. Compared with the south zone, the north zone had significantly lower coverage of stony coral (e.g. Acropora , Montipora and Pocillopora) and soft coral, juvenile coral density but significantly higher coverage of rock/rubble, sand, hydrocoral and sponge. Redundancy analysis demonstrated that turbidity and dissolved nutrients (dissolved inorganic nitrogen or NH 4 +) were the significant factors in explaining the spatial distribution of reef benthic substrata and coral communities in 2017. The remarked decline of live coral cover in the north zone of WZZ during 2007–2016 can be associated with intensive construction, land use change, and tourism development. These results suggested that anthropogenic disturbances may have degenerated environmental conditions and affected the coral reefs at WZZ. • Scleractinia coral species in 40 genera from 13 families were recorded. • Wuzizhou Island can be divided into the north and south zones. • Compared with the south zone, the north zone had significantly lower live corals. • Reef benthic and coral composition differed between the two zones. • Anthropogenic disturbance may take responsibility for the changes of corals. [ABSTRACT FROM AUTHOR]