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The trade winds cause strong upwelling in the eastern equatorial Pacific, and create the eastern Pacific Cold Tongue (EPCT) that has far‐reaching impacts on global climate. However, large discrepancies persist in quantifying 20th‐century EPCT sea surface temperature (SST) changes across different instrumental data sets. Here we synthesize four coral Sr/Ca‐SST records from the tropical central‐eastern Pacific to develop a Cold Tongue Index (CTI) reconstruction for 1887–1997. The coral CTI record shows a rapid 20th century warming of the EPCT, suggesting an underestimation of warming trends in instrumental CTI records. The decadal to multidecadal changes in reconstructed EPCT SST show an association with the Walker Circulation. Our reconstruction indicates that recent EPCT cooling during the global warming hiatus is not unusual in the context of the 20th century. Our results provide new evidence for 20th century EPCT SST changes and an observational constraint for predicting future tropical climate changes. Plain Language Summary: The tropical Pacific exhibits an asymmetric pattern of sea surface temperatures (SST) along the equator, with a warm pool in the west and a cold tongue in the east. The Eastern Pacific Cold Tongue (EPCT) plays a crucial role in influencing global climate. To date, however, considerable disagreement persists about changes and causes of the EPCT SST over the 20th century due to the sparse instrumental observations before ∼1960. Here we synthesize published coral Sr/Ca‐SST records from the tropical central‐eastern Pacific to develop a coral Cold Tongue Index (CTIcoral) for the period 1887–1997. The CTIcoral record correlates significantly with instrumental data since 1960, and thus allows reliable assessment of 20th century EPCT SST changes. Our record exhibits a rapid 20th century warming trend of the EPCT, indicating an underestimation of warming trends in instrumental CTI records. The decadal to multidecadal changes in CTIcoral also show an association with the Walker Circulation. Comparing the magnitude of the 1992–2011 trend in instrumental CTI with our reconstruction reveals that recent EPCT cooling during the global warming hiatus is not anomalous in the context of 20th century. Our findings have implications for predicting future EPCT SST changes by offering a constraint for model simulations. Key Points: Synthesizing coral Sr/Ca‐SST records yields robust estimates of 20th century warming trend in the eastern Pacific Cold Tongue (EPCT)A coral‐based reconstruction indicates an underestimation of 20th century EPCT warming trends in instrumental SST recordsRecent EPCT cooling during the global warming hiatus is not anomalous in the context of the 20th century [ABSTRACT FROM AUTHOR]

Strontium isotopes (87Sr/86Sr) are commonly used to assess the age of Cenozoic dolostones found on many isolated oceanic islands. The possible influence of Rubidium (Rb) content on the 87Sr/86Sr ratios, however, has generally been ignored. This critical issue is assessed by examining the 87Sr/86Sr ratios and elements (Rb, Sr, Al, Ti and K) of seventy‐one samples that came from a ca 339 m thick cored interval of Cenozoic dolomite on the Xisha Islands, South China Sea. For the dolomite from the upper Pliocene Yinggehai Formation (180.5 to 308.5 m; average 23% dolomite) there is a positive correlation between the 87Sr/86Sr ratios and Rb concentrations, whereas for the dolomite from the lower late Miocene Huangliu Formation (308.5 to 519 m; average >98% dolomite) such a correlation is not evident. Combined with high‐temperature experiments, correlation between Al, Ti, K, Rb and 87Sr/86Sr indicates that Rb containing old 87Rb from terrestrial materials modified the 87Sr/86Sr ratios of the Yinggehai dolomite, but not those from the Huangliu dolomite. This is mainly attributed to the different sources of terrestrial dust carried by different East Asian monsoon systems between the late Miocene and Pliocene, and probably also influenced by the dolomitization process to some extent. To test for 87Rb contamination, extrapolation of results from the Yinggehai dolomite and Huangliu dolomite indicate that concentrations of Rb < 1 ppm, Al < 1000 ppm, Ti < 15 ppm and K < 250 ppm in the dolomite indicates that terrestrial inputs are minimal and that the measured 87Sr/86Sr ratios can be used for determining the dolomitization age. Potentially, these concentration thresholds may serve as a screening criterion for assessing the reliability of Sr isotope chronostratigraphy of other island dolostones throughout the world. [ABSTRACT FROM AUTHOR]

Understanding the history of sea‐level changes in the past and the associated mechanisms is crucial for predicting sea level in the future. The South China Sea is the largest semi‐enclosed marginal sea in the western tropical Pacific. Previous studies showed that this region experienced several sea‐level fluctuations up to half a meter on centennial timescales ∼7,000 cal yr BP. These fluctuations were greater in magnitude than the rise in global mean sea level induced by greenhouse effect over the 20th century. However, whether such sea‐level fluctuations occurred in a wider temporal context and their potential causes remain unclear. To answer these questions, we reconstructed the mid‐Holocene sea‐level fluctuations in the northern South China Sea using nine coral microatoll fossils collected from Hainan Island. The results suggest that sea‐level fluctuations with amplitude of about half a meter on centennial timescales were common during 6,143–4,384 cal yr BP. Based on recent studies of sea‐level driving mechanisms in the South China Sea and paleoclimate reconstructions, we infer that these sea‐level fluctuations were likely driven by changes of Walker circulation intensity. Due to the internal variability of the climate system, the possibility of similar sea‐level fluctuations in the foreseeable future cannot be ruled out. Key Points: Microatolls on Hainan Island revealed multiple half‐meter sea‐level fluctuations on centennial timescale during the mid‐HoloceneThese sea‐level fluctuations are similar to those occurred ∼7,000 cal yr BP in other regions of the South China SeaThe responsible mechanisms were likely related to the changes of the Pacific Walker circulation intensity [ABSTRACT FROM AUTHOR]

Tropical cyclones (TCs) lead to huge economic losses and casualties in coastal regions, but multi‐decadal variation of TC remains poorly understood due to the limited length of observational records and low‐resolution reconstructions. Porites corals provide continuous and monthly resolved records that allow for the determination of weather‐timescale (weekly to monthly) extreme events, including TC, to overcome the above limitations. Here we synthesize five coral Δδ18O records from the South China Sea (SCS) and develop a coral TC frequency index, in good agreement with post‐1980 instrumental records and sediment‐based TC reconstructions over the past century. Our results indicate that TC frequency in the SCS exhibits pronounced decadal variations, with active TCs corresponding to the negative phase of the Pacific Decadal Oscillation. Our findings here provide novel evidence for past TC changes in the SCS and a constraint for predicting future TC changes. Plain Language Summary: The impact of tropical cyclones (TCs) on coastal regions results in significant economic losses and casualties. Due to the relatively short observations or low‐resolution records, assessing long‐term changes of TCs has suffered from large uncertainties. Porites corals are sensitive to environmental changes and can provide century‐long, monthly resolved records, which could serve as a potential archive for reconstructing past TCs. Here we present five coral Δδ18O records from the South China Sea (SCS) and develop two TC frequency indexes. Both the TCs generated in the SCS and those entering the SCS from the Western North Pacific are reflected in our coral‐based TCs reconstruction. In addition, our reconstruction suggests that the TCs in the SCS were increased in 1878–1888, 1894–1904, 1934–1952, 1971–1978, and 1995–2004, which corresponded to the negative phase of the Pacific Decadal Oscillation over the past century. Our findings provide new evidence for historical changes in TCs in the SCS and a valuable constraint for predicting future TC variations. Key Points: The low residual oxygen isotope values of coral strongly respond to tropical cyclones in the South China SeaExcluding temperature, we reconstruct tropical cyclone activities in the South China Sea over the past century using coral oxygen isotopesPacific Decadal Oscillation modulates tropical cyclones in the South China Sea over the past century [ABSTRACT FROM AUTHOR]

The growing threat of global warming on coral reefs underscores the urgency of identifying heat‐tolerant corals and discovering their adaptation mechanisms to high temperatures. Corals growing in intertidal rock pools that vary markedly in daily temperature may have improved heat tolerance. In this study, heat stress experiments were performed on scleractinian coral Porites lutea from subtidal habitat and intertidal rock pool of Weizhou Island in the northern South China Sea. Thermotolerance differences in corals from the two habitats and their mechanisms were explored through phenotype, physiological indicators, ITS2, 16S rRNA, and RNA sequencing. At the extremely high temperature of 34°C, rock pool P. lutea had a stronger heat tolerance than those in the subtidal habitat. The strong antioxidant capacity of the coral host and its microbial partners was important in the resistance of rock pool corals to high temperatures. The host of rock pool corals at 34°C had stronger immune and apoptotic regulation, downregulated host metabolism and disease‐infection‐related pathways compared to the subtidal habitat. P. lutea, in this habitat, upregulated Cladocopium C15 (Symbiodiniaceae) photosynthetic efficiency and photoprotection, and significantly increased bacterial diversity and coral probiotics, including ABY1, Ruegeria, and Alteromonas. These findings indicate that rock pool corals can tolerate high temperatures through the integrated response of coral holobionts. These corals may be 'touchstones' for future warming. Our research provides new insights into the complex mechanisms by which corals resist global warming and the theoretical basis for coral reef ecosystem restoration and selection of stress‐resistant coral populations. [ABSTRACT FROM AUTHOR]

Significant differences in environmental conditions between nearshore and offshore coral reefs lead to different symbiotic zooxanthellae density (ZD) of corals. From the perspective of energy supply, different ZD lead to different energy provided by the photosynthesis of zooxanthellae to the coral host. However, few studies have conducted a comparative analysis of coral trophic status (i.e., autotrophic photosynthesis of zooxanthellae and heterotrophic feeding of the host) between nearshore and offshore reefs. In this study, 70 coral samples of Favia palauensis were collected from the nearshore Sanya reefs, and offshore Xisha, Nansha reefs in the South China Sea (SCS). The ZD, δ15N of seawater particulate organic matter (δ15NPOM), host tissue (δ15Nh), zooxanthellae (δ15Nz) and the difference between δ15Nh and δ15Nz (i.e., △h−z 15N = δ15Nh−δ15Nz) were measured and statistically analyzed. The purpose is to elucidate the differences in the energy maintenance mechanisms of corals between nearshore and offshore reefs. Results show that ZD is significantly positively correlated with δ15Nz in all three reefs (p < 0.05). Corals in nearshore Sanya have higher autotrophic abilities than corals from offshore Xisha and Nansha reefs. By contrast, corals in offshore reefs are more dependent on heterotrophic feeding of the host to obtain energy. Our research demonstrate that corals can adjust their trophic status, especially improve their heterotrophic feeding intensity to meet energy needs under different environmental conditions. This dynamic adjustment of energy supply patterns is of great significance to improve coral's environmental adaptability. Plain Language Summary: Coral reefs are mainly divided into nearshore fringing reefs, barrier reefs and offshore atolls according to geographical distribution. Therein, ambient seawater in nearshore reefs are significantly affected by human activities and has relatively higher nutrient levels. In contrast, corals in offshore atolls are less affected by human activities as they are far away from the mainland, but they will be potentially affected by abnormal natural conditions. Different environmental conditions lead to significant differences in the physiological parameters of corals, such as symbiotic zooxanthellae density (ZD). From the perspective of energy supply, different ZD may lead to different energy provided by the photosynthesis of zooxanthellae to the coral host. However, few studies have conducted a comparative analysis of coral trophic status between nearshore and offshore reefs. Based on the δ15N labeling technology, we find that corals in nearshore fringing reefs have higher autotrophic abilities than corals from offshore reefs. By contrast, corals in the offshore reefs are more dependent on heterotrophic feeding of the host to obtain energy. This means that corals can adjust their trophic status to meet energy needs under different environmental conditions. This dynamic adjustment of energy supply patterns is of great significance to improve coral's environmental adaptability. Key Points: The δ15N can record coral trophic status changes between nearshore and offshore reefsCorals in nearshore reefs have higher autotrophic photosynthesis and heterotrophic energy than corals in offshore reefsCoral can independently adjust trophic status under different environmental conditions between nearshore and offshore [ABSTRACT FROM AUTHOR]

In recent decades, vanadium (V) levels in the environment have dramatically increased and will continue to rise alarmingly in the future. Conventional methods for assessing oceanic V typically only involved the collection of seawater and sediments, which significantly limited our understanding of the dynamics of oceanic V and its relationship to environment and climate. Here, the interannual temporal variations in surface seawater V levels in the northern South China Sea, were reconstructed utilizing a 137‐year record of V/Ca ratios from Porites lutea coral from Xiaodonghai Bay off Sanya. We observed that anthropogenic activities had a limited impact on the V levels of surface seawater in the study area, whereas V variability exhibited significant disparities across different time periods. Precipitation‐related submarine groundwater discharge (SGD) recharge was the primary driver of V variation prior to 1990, with tropical cyclones (TCs) playing a detectable role in total precipitation during this period. Conversely, changes in surface seawater V levels after 1990 were predominantly linked to increasingly intense upwelling driven by summer winds. The recharge processes in unconfined groundwater systems within the study area might generate favorable oxic and alkaline conditions, which facilitated mineral dissolution and/or desorption reactions that elevated V concentrations along the groundwater flow path, which were recorded in coral skeletal V/Ca ratios. This study confirmed the seawater V was dominated by SGD and upwelling near Sanya, providing essential evidence for comprehending the geochemical behavior of V and the impact of ocean‐atmospheric climate interactions on long‐term variations in seawater V levels. Plain Language Summary: Recently, the amount of vanadium (V) in our environment has skyrocketed and will only continue to increase. The traditional method of checking oceanic V levels involved collecting seawater and sediment, which provided an incomplete understanding of V behavior in different environments and its relationship to climate change. Therefore, we conducted a detailed study on surface seawater V levels in the northern South China Sea over several years. We observed that human activities had little impact on the surface seawater V levels in our study area, but there were significant variations in V changes across different temporal intervals. Before 1990, precipitation‐induced submarine groundwater discharge was the main cause of changes in V, while tropical cyclones played a minor role in rainfall. However, after 1990, surface seawater V levels were significantly affected by stronger upwelling caused by summer winds. Groundwater systems in the study area may have caused mineral dissolution or desorption reactions, leading to increased V concentrations detected in corals. We looked into where V comes from in surface seawater and what factors affect it, giving us some solid proof on how V behaves chemically and how ocean‐atmospheric climate changes can impact its levels over time. Key Points: Coral vanadium (V)/Ca ratios exhibit a remarkable correlation with submarine groundwater discharge (SGD) prior to 1990Enhanced upwelling activity may modify the relationship between surface seawater V levels and SGDTropical cyclones amplify the impact of SGD on seawater V level by causing heavy precipitation [ABSTRACT FROM AUTHOR]

The strontium‐to‐calcium (Sr/Ca) ratio of coral is widely used as a paleothermometer for tropical sea surface temperature (SST) at subannual resolutions. The fidelity of Sr/Ca‐derived SST estimates largely depends on the properties of the monthly age model selected. Here, we develop a revised monthly age model for coral Sr/Ca estimation from the northern South China Sea based on specific tie points and evaluate the impacts of different age models on SST reconstruction. Our results indicate that our revised monthly age model reduces conversion errors by up to nearly 20%–30% relative to previously reported values, thereby improving the precision of seasonal SST estimates and enabling better paleoclimate interpretations, such as El Niño–Southern Oscillation variability. The revised monthly age model provides a generalized approach for developing more robust seasonal resolution Sr/Ca–SST reconstructions in other regions. Key Points: We develop a revised monthly age model for coral Sr/Ca‐derived sea surface temperature estimatesThe new age model reduces errors by up to 20%–30% relative to previously reportedThe new age model improves the accuracy of the South China Sea climate and El Niño–Southern Oscillation reconstructions [ABSTRACT FROM AUTHOR]

Coral skeleton δ13C is a routinely measured indicator in modern insolation change research, but the knowledge of environmental and climatic signals recorded in its seasonality during geological time is sparse. In this study, we present eight Porites coral δ13C records from the mid‐late Holocene to the present from the northern South China Sea (NSCS). Compared with the main control factors for modern δ13C changes, coral δ13C seasonality in the NSCS since the mid‐Holocene shows a long‐term decreasing trend, which is consistent with the change trend as orbital‐induced (precession) insolation seasonal amplitude. By excluding other influencing factors, we speculate that the stronger coral δ13C seasonality (18.8%) over the mid‐Holocene than modern period is attributable to the metabolic effect, which predicts the stronger coral δ13C seasonality under stronger insolation seasonality. Our study has implications for coral δ13C seasonality as a potential indicator to record past insolation information under different climatic backgrounds. Plain Language Summary: Numerous studies have documented the seasonal features of fast‐growing modern coral skeleton δ13C in response to insolation variation. The environmental and climatic signals recorded by coral δ13C seasonality in the geological period remain unclear owing to the relatively short length of observation records. Here we present monthly resolved δ13C records in seven fossil Porites corals (5.6–3.6 ka BP, before 1950 CE) and one modern Porites coral (1987–2001 CE) from the northern South China Sea (NSCS). Compared with the widely accepted prevailing control factors for modern coral δ13C, our results indicated that the stronger coral δ13C seasonality (18.8%) over the mid‐Holocene compared to the modern period is consistent with the orbital‐induced (precession) insolation changes, which indicate a declining seasonality from the mid‐Holocene to present. By excluding other influencing factors, we infer that a tendency toward higher δ13C seasonality during the mid‐Holocene was primarily driven by the metabolic fractionation caused by the enhanced insolation seasonality. This study highlighted coral δ13C seasonality as a potential indicator for recording past insolation information. Key Points: The seasonal variation of modern coral skeleton δ13C in the northern South China Sea (NSCS) is primarily controlled by solar insolationCoral δ13C seasonality in the NSCS since the mid‐Holocene shows a long‐term decreasing trendThe decrease of orbital‐induced (precession) insolation seasonal amplitude led to the declining trend of δ13C seasonality [ABSTRACT FROM AUTHOR]

The El Niño–Southern Oscillation (ENSO) is the dominant interannual variability affecting global weather and climate. However, limited observational records hinder our understanding of the evolution of natural ENSO variability and its driving mechanisms. In this study, ENSO variations from 665 to 749 CE (Common Era) were investigated using monthly sea surface temperature (SST) records of the northern South China Sea derived from coral strontium to calcium ratios of sub‐fossil Porites obtained at the Xisha Islands. The results suggested the existence of cold conditions in this period relative to the twentieth century. No change in SST seasonality for the CE was found that is in agreement with the orbitally controlled insolation seasonality at that time. ENSO variability during 665–749 CE was enhanced by 39% than that during 1980–2014 CE and exhibited fluctuations. A persistent dampened ENSO variability with frequent El Niño events from 665 to 700 CE was followed by a rapid increase in variability to a level double that of the present. The frequency of La Niña events increased during this time. The abrupt transformation of ENSO activity at 700 CE was attributed to the increased natural radiative forcing induced by intense solar irradiance and weak volcanism. This paper demonstrates that ENSO variability can be influenced by external forcings, such as changes in solar and volcanic activity, and not only by the internal dynamics of the climate system. Plain Language Summary: Reconstructing the amplitude and frequency of historical El Niño and La Niña events will allow us to better understand the driving mechanisms of their evolution and improve predictions of ENSO under anthropogenic climate change. This study reconstructed monthly sea surface temperature (SST) from 665 to 749 CE using a continuous sub‐fossil coral Sr/Ca record from Xisha Islands. We demonstrated that the northern South China Sea and its adjacent area experienced cold conditions during this period, with no change in SST seasonality relative to the present. Our results also revealed that ENSO variability during 665–749 CE exhibited significant fluctuations from a state with dampened ENSO to one with amplified ENSO, accompanied by a transition from frequent El Niño to La Niña anomalies. The abrupt increase in ENSO variability after 700 CE was triggered by the increased solar irradiance and weak volcanic eruptions. This suggests that in addition to the internal dynamics of the climate system, ENSO variability is also influenced by external forcings. Key Points: Cooler conditions and similar sea surface temperature seasonality compared to the present characterized 665–749 CEEl Niño–Southern Oscillation (ENSO) variability during 665–749 CE was 39% higher than that during 1980–2014 CEEnhanced solar activity triggered an abrupt increase in ENSO variability at 700 CE [ABSTRACT FROM AUTHOR]

Cadmium (Cd) geochemical cycle plays a significant role in the composition and function of the marine ecosystem. Skeletal cadmium‐to‐calcium (Cd/Ca) ratios in hermatypic corals have been applied to reconstruct the historical changes of oceanic and climatic processes, yet there was no systematic evaluation of this tracer's natural variability in high resolution over time. Here, we reported a coral skeletal Cd/Ca record in monthly resolution from 1999 to 2008 CE and reconstructed the history of Cd contents in surface seawater in the northern South China Sea. A significant seasonal variation (higher in the winter but lower in the summer) of Cd contents in surface seawater can be identified. We found that the seasonal variations in coral skeletal Cd/Ca ratios exhibited significant trends coupled with the surface wind speeds, indicating that strong winds had likely driven the vertical seawater mixing process and then induced the process of sediment remobilization on the shelf, which significantly increased Cd contents in surface seawater. The reduction in Cd contents in surface seawater due to biological processes might be masked by the impacts of surface winds. Importantly, we also observed that coral skeletal Cd/Ca records in the winter showed significant correlations with the winter monsoon index, highlighting the possibility as a new proxy of winter monsoon in the non‐upwelling shelf environments. Plain Language Summary: Cadmium (Cd) is a nutrient element absorbed by phytoplankton in surface seawater, showing a distribution of low surface content and high bottom content. In order to determine the seasonal variations of Cd content in surface seawater in the northern South China Sea, we analyzed the coral skeletal Cd/Ca ratios in monthly resolution (1999–2008 CE) and finally concluded that the process of sediment resuspension and vertical mixing of seawater driven by winter monsoons is the main reason. The reduction of Cd contents in surface seawater due to biological processes was masked by the impacts of surface winds. In the past, Cd content in seawater/coral has been used to track the history of upwelling and El Niño Southern Oscillation, but the potential indicative on winter monsoon has not been reported so far. Considering that the trend between coral skeletal Cd/Ca ratios and average wind speeds showed a great agreement, we suggested that coral skeletal Cd/Ca ratios in the winter might be a potential proxy of winter monsoon. Key Points: Coral skeletal Cd/Ca ratios in monthly resolution were first reportedSeawater mixing process and sediments resuspension caused by winter monsoon are responsible for Cd seasonal variations in surface seawaterCoral skeletal Cd/Ca ratios have potential to be a novel proxy for winter monsoon [ABSTRACT FROM AUTHOR]

BACKGROUND β‐Glucosidases (3.2.1.21) play essential roles in the removal of nonreducing terminal glucosyl residues from saccharides and glycosides. However, the full potential and different applications of recombinant high‐yield microbial β‐glucosidase‐producing systems remain to be tackled. RESULTS: A β‐glucosidase gene designated as Mg132 was isolated from a coral microorganism by high‐throughput sequencing and functional screening. The deduced amino acid sequences of Mg132 showed a highest identity of 97% with β‐glucosidase predicted in the GenBank database. This gene was cloned and overexpressed in Escherichia coli BL21 (DE3) for the first time. The optimal pH and temperature of purified recombinant Mg132 were 8.0 and 50 °C respectively. It exhibited a high level of stability at high concentration of glucose and ethanol, and glucose concentrations below 300 mmol L–1 distinctly stimulated p‐nitrophenyl‐β‐d‐glucopyranoside hydrolysis, reaching 200% at 15% ethanol. The Km and Vmax values were 0.293 mmol L–1 and 320 μmol min−1 mg−1 respectively while using p‐nitrophenyl‐β‐d‐glucopyranoside as a substrate. Wine treated with Mg132 had an obvious positive catalytic specificity for glycosides, which give a pleasant flavor of temperate fruity and floral aromas. The total concentration of fermentative volatiles was 201.42 ± 10.22 μg L−1 following Mg132 treatment and 99.21 ± 7.72 μg L−1 in control samples. CONCLUSION: Good tolerance of winemaking and aroma fermentative properties suggest that Mg132 has potential application in aroma enhancement in wine and warrants further study. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

We used the top age of storm‐relocated coral blocks (SRCBs) from Xisha Islands and Huangyan Island, South China Sea (SCS), in combination with existing paleotempestology records and instrumental climatic data, to reconstruct the spatio‐temporal changes in tropical cyclone (TC) activity over the past millennium, and to project its future trends in the Northwestern Pacific region. We found a positive correlation between the frequencies of TCs, typhoons, and super‐typhoons and the NINO3.4 on the interannual timescale during 1945–2019. TCs latitude has a significant positive correlation with sea surface temperature, with a northward migration rate of 80 ± 11 km per decade during 1951–2019. Coral δ18O can well indicate the month of paleo‐TCs occurrence. The frequency of SRCBs (and by inference, TCs) is relatively low during relatively warm periods (RWP) but high during relatively cold periods (RCP) in the SCS. The spatio‐temporal pattern inferred from paleotempestology records further supports the notion of North‐South migration in TC activity as revealed by the instrumental record in this study. TC activity mainly affected relatively low latitudes (e.g., Philippines, Vietnam, and Hainan, Guangdong, Taiwan) during the RCP (AD 1450–1900), but it migrated from low latitudes towards higher latitudes during the RWP (AD 1000–1450), affecting locations such as Zhejiang, Jiangsu, and Shandong, southwestern Japan, the Korean Peninsula, and even Northeast China. Fujian and northern Guangdong may be in a transition zone of paleo‐TC activity between the North and the South in the past millennium. As global warming continues, the mean tracks and landfall locations of TCs will continue to migrate northward in this region. Key Points: Tropical cyclones (TC) latitude and sea surface temperature are positively correlated; TCs had a northward migration rate of 80 ± 11 km per decade during AD 1951–2019The coral δ18O can indicate the month when the paleo‐TC event happened; SRCBs appeared more frequently during relatively cold periods in the South China SeaPaleo‐TCs mainly affected relatively high latitudes during climatically warm periods, but lower latitudes during cold periods in the Northwestern Pacific region [ABSTRACT FROM AUTHOR]

Pyrosequencing (PSQ) represents the golden standard for MGMT promoter status determination. Binary interpretation of results based on the threshold from the average of several CpGs tested would neglect the existence of the "gray zone". How to define the gray zone and reclassify patients in this subgroup remains to be elucidated. A consecutive cohort of 312 primary glioblastoma patients were enrolled. CpGs 74‐81 in the promoter region of MGMT were tested by PSQ and the protein expression was assessed by immunohistochemistry (IHC). Receiver operating characteristic curves were constructed to calculate the area under the curves (AUC). Kaplan‐Meier plots were used to estimate the survival rate of patients compared by the log‐rank test. The optimal threshold of each individual CpG differed from 5% to 11%. Patients could be separated into the hypomethylated subgroup (all CpGs tested below the corresponding optimal thresholds, n = 126, 40.4%), hypermethylated subgroup (all CpGs tested above the corresponding optimal thresholds, n = 108, 34.6%), and the gray zone subgroup (remaining patients, n = 78, 25.0%). Patients in the gray zone harbored an intermediate prognosis. The IHC score instead of the average methylation levels could successfully predict the prognosis for the gray zone (AUC for overall survival, 0.653 and 0.519, respectively). Combining PSQ and IHC significantly improved the efficiency of survival prediction (AUC: 0.662, 0.648, and 0.720 for PSQ, IHC, and combined, respectively). Immunohistochemistry is a robust method to predict prognosis for patients in the gray zone defined by PSQ. Combining PSQ and IHC could significantly improve the predictive ability for clinical outcomes. [ABSTRACT FROM AUTHOR]

Summary: Environmental conditions between the outer reef slope (ORS) and lagoon in tropical atolls are significantly different, but the variations of juvenile coral‐microbiomes in the two environments and their relationship with coral thermal acclimatization are poorly understood. We explored this issue based on local water conditions and the microbiome of juvenile corals in the ORS and lagoon in the central South China Sea. Coral‐symbiotic Symbiodiniaceae showed significant differences among coral species; Pocillopora verrucosa and Pachyseris rugosa in the ORS, and Acropora formosa in the lagoon were dominated by Durusdinium, but other corals were dominated by Cladocopium. Although A. formosa in the ORS were dominated by Cladocopium (C3u), they were dominated by Durusdinium (D1/D1a) and Cladocopium (C50) in the lagoon. Other coral species were both dominated by Cladocopium in the lagoon and ORS. The relative abundance of bacteria in the Deinococcus–Thermus was generally higher in the lagoon corals than in the ORS corals. Our study indicates that P. verrucosa, P. rugosa and Porites lutea may have high thermal tolerance based on the relatively high abundance of heat‐tolerant Durusdinium and Thermus scotoductus. Likewise, A. formosa in the lagoon may acclimatize to the thermal environment based on a high relative abundance of heat‐tolerant Durusdinium. [ABSTRACT FROM AUTHOR]

Aim: In this study, we investigated whether environmental factors can effectively control the spatial distribution of various benthic algae and examined the critical ecological impacts of algae on corals across the South China Sea (SCS). Relationships between benthic algae and environmental factors were assessed, and potential ecological impacts of algae on coral communities were evaluated across spatial scales. Location: A total of 104 sites at 12 coral reefs in four coral reef regions (CRRs) of the SCS (latitude range of 9–22° N). Taxa: Turf algae, macroalgae (including fleshy macroalgae and Halimeda), crustose coralline algae (CCA), coral and juvenile coral. Methods: Using diver‐based surveys (2015–2018), we investigated four CRRs with different reef distance to mainland (RDM) across the SCS. We obtained field data on benthic algal composition and cover, coral cover and diversity, and juvenile coral density. We also measured and collected the environmental factors (including seawater environmental parameters and reef fish diversity). Results: The cover of turf algae and CCA gradually decreased and increased, respectively, with an increase in RDM, which had a strong relationship with the gradually changing environmental factors. Random forest models suggested that nutrients, reef fish diversity, seawater transparency and temperature were the most important factors for predicting turf algae and CCA cover. Linear regression analyses showed a significant relationship between the turf algae, macroalgae, and CCA covers, and juvenile coral density. Main conclusions: Our results showed that gradually changing environmental factors were correlated with the spatial distributions of turf algae and CCA. However, the natural biophysical relationships between macroalgae and environmental factors may be disrupted by turf algal overgrowth and nutrient subsidies. Increases in all benthic algal groups significantly impacted coral recruitment, highlighting the critical role of benthic algae in determining the recovery trajectory of the Indo‐Pacific reefs that are threatened by human activities. [ABSTRACT FROM AUTHOR]

The El Niño–Southern Oscillation (ENSO) dominates interannual climate variability worldwide and has important environmental and socio‐economic consequences. However, determining the evolution of ENSO variability and its long‐term response to climate forcing remains an ongoing challenge owing to the limited instrumental records. In this study, we quantified ENSO variability via an empirically calibrated threshold and sliding variance windows using monthly sea‐surface temperature (SST) anomalies based on Porites coral Sr/Ca records from the Xisha Islands in the northern South China Sea. Instrumental SST anomalies from the Xisha Islands correctly captured increasing ENSO variability in the twentieth century, with ENSO detection skills similar to those for Niño3.4 regions. Coral Sr/Ca‐SST anomalies can also serve as sensitive and robust proxies for ENSO variability. Sub‐fossil coral Sr/Ca‐SST anomalies indicated intensified ENSO variability at the end of the Medieval Climate Anomaly (MCA) from 1149 to 1205 ± 4.9 (2σ) Common Era (CE). Combining our records with other ENSO‐sensitive proxy reconstructions from the tropical Pacific, we observed fluctuating ENSO variability during the MCA and intensified ENSO variability for the late MCA. Considering the fewer and low intensity fluctuations associated with external climate forcing and the absence of a coherent temporal correspondence of ENSO activity with solar irradiance and volcanic eruption during the MCA, we hypothesized that the internal dynamics of the climate system play a prominent role in modulating ENSO variability and its evolution, which is supported by unforced climate model simulations and coral reconstructions across the tropical Pacific. Key Points: Coral Sr/Ca‐sea‐surface temperature variations from the northern South China Sea are a reliable proxy of El Niño–Southern Oscillation variabilityIntensified El Niño–Southern Oscillation variability occurred during the late Medieval Climate AnomalyUnforced internal variability within the climate system likely play a prominent role in modulating El Niño–Southern Oscillation variability [ABSTRACT FROM AUTHOR]

Great efforts have been made to understand the impacts of the 1997 Indonesian wildfires on land ecology and human health, yet its influences on marine environments are poorly understood owing to sparse observations. Here we present weekly to monthly resolution coral δ13C records across the South China Sea in conjunction with a regional ocean general circulation model to study the effects of these cataclysmic wildfires on nearby oceans. Large and persistent negative δ13C excursions were found in corals from the interior South China Sea several months after the wildfires. This delay indicates that the 13C‐depleted ash fallout was distributed by ocean currents rather than direct atmospheric transport, which is supported by the results of our numerical model. Thus, the impacts of tropical wildfires on marine ecology may last for 1 year and extend thousands of kilometers from the burning center. Plain Language Summary: Tropical wildfires, intensified by extreme weather events and land use change, have continued to increase during this century, causing serious damage to the rainforests and local economies as well as human suffering and death. The threats of tropical wildfires to nearby oceans have been given little attention and are largely unknown because of limited observations. Here we use multiple coral records with weekly to monthly resolution from five sites near and around the South China Sea and a computer model to study the influences of the 1997 Indonesian wildfires on the ocean. We find a previously unrecognized ash fallout signal recorded in the corals in the interior of the South China Sea. Our model results indicate that the penetration of ash fallout into the South China Sea occurred through ocean currents rather than direct atmospheric transport. This study shows that the impacts of tropical wildfires on oceans may last for 1 year and can extend for thousands of kilometers from the source. We also show the potential for using coral records with computer modeling to identify and study the frequency and extent of past megafires. Key Points: A large negative excursion in δ13C values during summer–winter 1998 was detected in corals from the interior of the South China SeaModel shows that ash fallout from the 1997 Indonesian wildfires distributed by currents was responsible for the negative δ13C excursionNetworks of coral δ13C have great potential to record past pantropical wildfires [ABSTRACT FROM AUTHOR]

Excess anthropogenic phosphorus (P) supplied to marine systems, which may subsequently jeopardize ecosystem structure and function, has altered the P balance and quadrupled its flow. However, due to the diversity of P sources, the unpredictability and variability of human activities, and the absence of long‐term records, it remains uncertain how long the effects of excess P persist in aquatic ecosystems, and whether it stimulates gross primary productivity. In this study, we utilized geochemical proxies in coral skeletons from an atoll in the Xisha Islands of the South China Sea to reconstruct historical patterns of P in surface seawater. This atoll has remained in a natural state for an extended period of time, except for a short period of unambiguously documented guano extraction. Analyses of coral skeletons dating back to 1851 CE distinctly show that the P concentration in surface seawater increased abnormally in the 1960s. We deduced that guano extraction at that time led to an abrupt increase in the long‐term equilibrium of seawater P concentration. Subsequent P addition appeared to have continued for at least ~30 years after phosphorite exploitation ceased, and P showed a decay period that was longer than that of other elements. Similar temporal trends of coral P/Ca and δ13C indicated that elevated marine primary productivity was associated with increased P. Large inputs within a short period, as well as the continued influence of P over the long term, can serve as a natural ecological analog for coral reefs subject to nutrient contamination. Plain Language Summary: Nutrient contamination in tropical islands is considered a major cause of declines in the health of coral reefs. However, without a long‐term record, it is difficult to determine nutrient variations in the surface seawater clearly. Using P/Ca ratios in the aragonite layer of Porites lutea coral, we found that there was an abnormal increase in P concentrations in surface seawater surrounding Yongxing Island, of the Xisha Islands of the South China Sea, in the 1960s. We inferred that this phenomenon was related to the government's exploitation of guano. Since then, these P have continued to precipitate from the surface waters of nearby coral reefs for at least ~30 years. This trend differs from that of other elements (this included the time taken for P from the island to reach seawater after exploitation of the guano). In addition, we found that coral δ13C peaked and changed in line with P/Ca during the 1960s to 2005. Large inputs of P and long‐term persistent effects in the Xisha Islands can be used as a natural ecological simulation, similar to other coral reefs that have become eutrophic by anthropogenic activities. Key Points: Phosphorus input from guano extraction had a significant stress on remote coral reefsProlonged elevated P in seawater were related to its involvement in productivityExcess P in seawater persisted for ~30 years after the artificial disturbance [ABSTRACT FROM AUTHOR]

The knowledges of trophic status (i.e., autotrophy/heterotrophy) of corals are helpful for understanding the mechanisms driving their environmental stress tolerance and bleaching resilience. We conducted this study to elucidate the differences in trophic status among corals of different genera and then explore the implication of trophic status for their different environmental stress tolerance. In this study, 117 coral samples including five genera (i.e., relatively stress‐tolerant massive genera Porites, Favites, and Favia and relatively vulnerable plating genus Pavona and branching genus Acropora) were collected from Weizhou Island, northern South China Sea. The symbiotic zooxanthellae density, δ13C of host tissues (δ13Ch), and symbiotic zooxanthellae (δ13Cz) were measured. Besides, the difference in values between δ13Ch and δ13Cz (i.e., △h‐z 13C) was analyzed. Our results indicated that both zooxanthellae density and δ13Cz values of Porites, Favites, and Favia are higher than that of Pavona and Acropora and indicate that autotrophic photosynthesis intensity of symbiotic zooxanthellae of Porites, Favites, and Favia is higher than that of Pavona and Acropora. Besides, both δ13Ch and △h‐z 13C of Porites, Favites, and Favia are lower than that of Pavona and Acropora and indicate a higher contribution of heterotrophic predation to the coral host of Porites, Favites, and Favia. These comparisons suggest that trophic status of relatively stress‐tolerant Porites, Favites, and Favia is more plasticity than vulnerable Pavona and Acropora, which is conducive to maintain a positive energy budget. This is one of important factors leading to different environmental stress tolerance and bleaching resilience among corals of different genera. Key Points: Autotrophic photosynthesis and heterotrophic predation of massive corals are higher than that of plating and branching coralsTrophic status of relatively stress‐tolerant massive corals is more plasticity than that of vulnerable plating and branching coralsDifferent trophic status is one of important factors leading to different environmental stress tolerance and bleaching resilience [ABSTRACT FROM AUTHOR]

As one of the microcontinents dispersed in the South China Sea (SCS), the Xisha microcontinent lacks the petrological evidence of the Cenozoic magmatic activity and basement. Well CK‐2, as a full‐coring kilometre‐scale major scientific drilling in Xisha Islands in the northwestern SCS, drilled through the thick reefal limestone and into the underlying basaltic pyroclastic rocks basement. This paper presents zircon U–Pb age and mineral chemistry of clinopyroxenes from the basaltic pyroclastic rocks. Mineral composition of the clinopyroxenes suggests that most of the clinopyroxenes are composed of diopside, which contains relatively high Al(w (Al2O3) = 5.03%–10.25%) and Ti(w (TiO2) = 2.2%–4.95%). The clinopyroxene discrimination diagrams show that the primary magma is alkaline basalt and likely generated in an intraplate tectonic setting. U–Pb dating of zircons by LA‐ICP‐MS yielded a wide range of ages: 36–33, 116–104, 148–140, 207–196, 255–236, 440, 808–749, and 2,440–1185 Ma. The youngest group has an average age of 35.5 ± 0.9 Ma, which is considered as the maximum age of the basalt eruption. The 2440 ± 19 Ma, which is the oldest zircons in the SCS, are firstly found in the basaltic pyroclastic rocks from the SCS, suggesting that the SCS may contain very old materials. The ages of the inherited zircons are comparable to magmatic activities that occurred around the SCS, implying that they were probably once linked and an integrated part of Gondwana. The ancient continental basement has experienced multistages magmatic events. [ABSTRACT FROM AUTHOR]

The decadal variability of ocean primary productivity (PP) has mainly been studied using relatively short term satellite data, limiting its in‐depth analysis. Here, by removing the influence of the 13C Suess effect, we extract the PP signal on decadal timescales using a record of coral δ13C values from the northern South China Sea (NSCS), where the physical‐biogeochemical conditions are influenced largely by the winter monsoon. Our results show that the PP in the NSCS increased from 1851 to the 1920s and decreased from the 1920s to 2007, and large superimposed decadal‐scale changes were observed. The in‐phase relationship observed between the PP reconstruction and winter monsoon records suggests that the changes in the PP in the NSCS are linked to decadal‐scale changes in the winter monsoon. Considering that the winter monsoon intensity may weaken in the future under global warming, the PP in the NSCS might decrease in the coming decades. Plain Language Summary: Marine phytoplankton contributes roughly half of the global primary production and thus constitutes a vital component of the marine ecosystem that serves as the foundation of the marine food web. Due to the relatively short length of observation records, evaluations of the long‐term changes in ocean primary productivity (PP) have suffered from large uncertainties, which have hampered further discussion of the decadal variability of PP in a long‐term context. To discuss the decadal variability of the PP beyond the range of satellite observations, we present a coral‐based PP reconstruction since 1851 CE from the northern South China Sea (NSCS), where the physical‐biogeochemical conditions are influenced largely by the winter monsoon. Our results show considerable decadal variability of the PP in the NSCS superimposed on a pre‐1920s increase and a post‐1920s decrease. We also found an in‐phase relationship between the decadal variability of the reconstructed PP and the winter monsoon records over the past 150 years, indicating that the PP in the NSCS is linked to changes in the winter monsoon forcing on decadal timescales. Considering that the winter monsoon intensity may weaken in the future under global warming scenarios, the PP in the NSCS might decrease in the coming decades. Key Points: The decadal variability of primary productivity was extracted from a coral δ13C record by removing the influence of the 13C Suess effectThe coral‐based primary productivity reconstruction for the past 150 years showed a pre‐1920s increase and a post‐1920s decreaseThe primary productivity of the northern South China Sea varied in phase with the intensity of the winter monsoon on decadal timescales [ABSTRACT FROM AUTHOR]

To date, the decadal variability of the Global Monsoon (GM) has been mainly studied using instrumental data collected over the last 50 years, and further discussion has been hampered by the limited data length. Here, we present a coral δ18O record from the northern South China Sea, where the hydrology is related to the seasonal Intertropical Convergence Zone (ITCZ) migration, and we use this record to reconstruct the decadal migration of the ITCZ since 1851 A.D. Combining our record with a synthesis of monsoon records reveals an anti‐phase inter‐hemispheric variability of the GM over the last 150 years, indicating that the decadal‐scale hydrologic variability in the tropics is modulated by the meridional migration of the ITCZ. The plausible relationship observed between the decadal variability of the GM and the Atlantic Multidecadal Oscillation suggests that the decadal variability of tropical hydrological changes is likely linked to the climate perturbations in the North Atlantic. Plain Language Summary: The prediction of monsoon variability in the coming decades will be of great importance for policy‐making and socio‐economic development. The Global Monsoon (GM) is the global‐scale seasonal atmospheric overturning associated with the migration of the Intertropical Convergence Zone (ITCZ). The variability and dynamics of the GM on decadal timescales are still unclear due to the limited length of the instrumental data (< 50 years). Here, we integrated a synthesis of the monsoon and the ITCZ records, including published records and our new coral record, and found that the GM varied in an anti‐phase inter‐hemispheric mode on decadal timescales associated with the ITCZ migration over the past 150 years, suggesting that the simultaneous intensification of the monsoons in both hemispheres since the ~1980s was unusual in a long‐term context. The linkage between the decadal variability of GM and the Atlantic Multidecadal Oscillation/Variability indicated that the North Atlantic has been driving the anti‐phase inter‐hemispheric variability of the GM on decadal timescales. Key Points: The coral δ18O record from the northern South China Sea captures the migration of the regional ITCZ on decadal timescalesThe Global Monsoon varied in an anti‐phase inter‐hemispheric mode on decadal timescales associated with the ITCZ migration since 1851 A.DThe decadal variability of the Global Monsoon was found to be linked to the Atlantic Multidecadal Oscillation [ABSTRACT FROM AUTHOR]

The article talks about the geophysical method of natural gamma radiation applied in stratigraphic classification, counting the gamma photons emitted by natural radionuclides that originates from the interior of the Earth and its redistribution during the formation of rocks and minerals. It talks about the use of natural gamma radiation in search of uranium mine, to identify lithological profile, clay mineral typing and low energy resolution of gamma spectrometry.

It is well known that coral thermal bleaching is mainly caused by abnormally high temperatures, but the spatial/intergeneric variation in coral‐algal symbiosis and its linkage to coral bleaching susceptibility is not well understood. In this study, 654 coral samples were collected from six coral reef regions (CRRs) in the South China Sea (SCS), between the Nansha Islands (~10°N) and Daya Bay (22°50′N). They were analyzed to explore how geographical/environmental variation affects coral bleaching susceptibility. The results showed significant spatial and intergeneric variation in zooxanthellae density, Chl a content, and tissue biomass. Massive corals generally showed higher values than branching corals for all three parameters across CRRs. Spatial analysis showed that these parameters were lowest in the Nansha Islands and highest in Daya Bay, indicating increases with latitude. Several factors may have accounted for this trend, with the most important being sea surface temperature and nutrients. Additionally, we observed a relationship between physiological parameters and bleaching susceptibility, which was that branching corals had greater bleaching susceptibility than massive corals. Coral community composition and live coral cover data showing increasing dominance of massive corals in the SCS support the above inference. Relatively high‐latitude areas have been proposed as potential refuges for corals under continued global warming and the physiological parameters in the present study seem to support this. However, in spite of the aforementioned results, the smallest live coral cover was found in the northern CRRs. This suggests that this refuge function is currently compromised, mainly due to increasing destructive anthropogenic actions. Key Points: The spatial variation in all of the coral physiological parameters used suggests significant increase with the increase in latitudeThe intergeneric variation in the parameters used affects coral bleaching susceptibility and adaptability to environmental stressThe potential of the northern South China Sea to serve as a coral refuge is currently being compromised by local anthropogenic activities [ABSTRACT FROM AUTHOR]

Abstract: Coral bleaching is becoming a serious issue for coral reefs under the stress of global warming. However, whether it has occurred in the past in times of thermal stress remains unclear. Moreover, an understanding of historic coral bleaching events would greatly improve our insight into the adaptive capabilities of corals under such stresses. It is known that Porites corals, a massive coral, have relatively high levels of symbiotic zooxanthellae and a strong thermal tolerance when compared with most other corals (and particularly branched corals). Thus, growth hiatuses and/or mortality surfaces of fossil Porites may be used to indicate past ecological or environmental stress events, such as severe bleaching. In this study, monthly geochemical and isotopic environmental proxies of four fossil Porites corals with well‐preserved growth hiatuses and mortality surfaces (aged 3,800–4,200 years before 2013 A.D.), collected from Wenchang fringing reef, Hainan Island, Northern South China Sea were analyzed. Specifically, the Sr/Ca, δ18O, and δ13C were measured with a monthly resolution for each sample. These environmental proxies were used to reconstruct the sea surface temperature (SST), sea surface salinity (SSS), and physiological activity of the coral at the time when the growth hiatuses and/or mortality surfaces occurred. These data were subsequently used to determine the causes of coral mortality and growth discontinuity in each case. The results show that growth hiatuses and mortalities mainly occurred in summer, with high SST (31–34°C) and SSS (32.8–38.4). In addition, abrupt negative shifts of 2–3‰ in δ13C were observed in almost all of the surfaces of growth hiatus and mortality, indicating a dramatically reduced level of photosynthetic activity in symbiotic zooxanthellae. Because of the above reasons, we conclude that the frequently observed mortality and growth discontinuity of Porites corals from the mid‐Holocene is evidence for thermal bleaching events in the past. That is, coral bleaching has occurred 3,800–4,200 years ago and is not a new phenomenon. [ABSTRACT FROM AUTHOR]

BACKGROUND The heterogeneous photo-Fenton-like process is emerging as a promising treatment of dye-containing wastewater because of its economic feasibility and high efficiency. However, it is still required to develop photo-Fenton-like catalysts with highly selective degradation ability and reusability. RESULTS Inorganic-framework molecularly imprinted Fe-doped TiO2 composites ( MIP/Fe- TiO2) were successfully prepared by the sol-gel method, with acid orange II as the template and TiO2 as the matrix material. The photo-Fenton-like catalysts were characterized using FESEM, EDS, BET, X-ray diffraction, FT-IR spectroscopy and UV-vis diffuse reflectance spectroscopy. These methods revealed the well-crystallized anatase phase and good nanometer-level particle sizes. The adsorption property and photo-Fenton-like activity of the catalysts were also studied in single and binary systems, respectively. CONCLUSIONS Compared with non-imprinted Fe- TiO2 composites ( NIP/Fe- TiO2), MIP/Fe- TiO2 showed higher adsorption capacity and selectivity toward the template molecule. In addition, it was found that the molecular recognition ability of MIP/Fe- TiO2 provided the catalysts with rapidly selective photo-Fenton-like degradation of low target pollutant levels (20 mg L−1) in the presence of high levels of interferential pollutant sodium dodecyl benzene sulfonate (100 mg L−1). Moreover, because of the stable physicochemical properties of the inorganic framework, the new photo-Fenton-like catalysts were resistant to photochemical attack and showed favorable reusability. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Widespread coral bleaching and mortality associated with global warming have occurred frequently since the phenomenon was first documented in the early 1980s. One such episode that occurred in 1991 over the tropical Pacific‐Indian Ocean region has been attributed to high summer sea surface temperatures. However, we found that sea surface temperature values from the South China Sea region do not provide a comprehensive explanation for the event. Our results, based on time series records of rare earth elements, trace element Al/Ca ratios, and microdomain images from corals in the South China Sea, suggest that this coral mortality event was exacerbated by heavy ash fallout from the cataclysmic 1991 volcanic eruption of Mount Pinatubo. Our findings highlight the profound impact of a volcanic eruption on the modern vulnerable coral reef ecosystems, already under the stress of global warming. Plain Language Summary: Intensive and frequent coral bleaching events have occurred under global warming conditions in recent decades. However, abrupt and extensive mortality episodes, such as which occurred in the South China Sea in mid‐1991, cannot be explained solely on the basis of high summer sea surface temperatures. Here we examine this event in the light of time series of rare earth elements, trace element Al/Ca ratios, and microdomain images for coral samples collected in the South China Sea region. Our results suggest that the second‐largest volcanic eruption of the 20th century, the 1991 Mount Pinatubo volcanic eruption, exacerbated this coral mortality event. The sensitive impacts of such a volcanic eruption on modern vulnerable coral reefs, associated with the stress of thermal conditions, are demonstrated. Key Points: This study reports that the mortality of modern coral reefs could be exacerbated by volcanic eruptionsThe anomalies of rare earth contents and Al/Ca ratios associated with microdomain images indicate an external impact from the 1991 PinatuboOur results highlight amplified responses of vulnerable coral reefs to environmental changes under global warming [ABSTRACT FROM AUTHOR]