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In the current study, to investigate the impacts of the wetness–dryness encountering of the upstream inflow and downstream salt intrusion on the water supply of the Pearl River Delta, we developed a water evaluation and planning (WEAP)-based water resources allocation model to calculate water supply schemes for the Pearl River Delta under 10 different scenarios. The impact of the scenarios on the water supply scheme of the Pearl River Delta was investigated. The results showed that (1) the water shortage of the Pearl River Delta is highly dependent upon the dryness combination of the upstream runoff during the dry period, in particular to the cities at the Pearl River Delta estuary, the water shortages are seriously influenced by saltwater intrusion; and (2) the water transfer projects could alleviate the water supply pressure of the Pearl River Delta when there is an extreme or more dryness encounter of upstream runoff. However, when extreme dryness events are impacting the upstream runoff of the West River, the impact of the water transfer projects is weakened and much of the critical upstream runoff for saltwater suppression cannot be satisfied, which largely impacts water withdrawals at the downstream cities in the Pearl River Delta estuary.

The hydrological process in the dry–warm valley of the mountainous area of southwestern China has unique characteristics and has attracted scientific attention worldwide. Given that this is an area with fragile ecosystems and intensive water resource conflicts in the upper reaches of the Yangtze River, a systematic identification of its hydrological responses to climate and land use variations needs to be performed. In this study, MIKE SHE was employed and calibrated for the Anning River Basin in the dry–warm valley. Subsequently, a deep learning neural network model of the long short-term memory (LSTM) and a traditional multi-model ensemble mean (MMEM) method were used for an ensemble of 31 global climate models (GCMs) for climate projection. The cellular automata–Markov model was implemented to project the spatial pattern of land use considering climatic, social, and economic conditions. Four sets of climate projections and three sets of land use projections were generated and fed into the MIKE SHE to project hydrologic responses from 2021 to 2050. For the calibration and first validation periods of the daily simulation, the coefficients of determination (R) were 0.85 and 0.87 and the Nash–Sutcliffe efficiency values were 0.72 and 0.73, respectively. The advanced LSTM performed better than the traditional MMEM method for daily temperature and monthly precipitation. The average monthly temperature projection under representative concentration pathway 8.5 (RCP8.5) was expected to be slightly higher than that under RCP4.5; this is contrary to the average monthly precipitation from June to October. The variations in streamflow and actual evapotranspiration (ET) were both more sensitive to climate change than to land use change. There was no significant relationship between the variations in streamflow and the ET in the study area. This work could provide general variation conditions and a range of hydrologic responses to complex and changing environments, thereby assisting with stochastic uncertainty and optimizing water resource management in critical regions.

Massive diagnostic testing has been performed for appropriate screening and identification of COVID-19 cases in the ongoing global pandemic. However, the environmental impacts of COVID-19 diagnostics have been least considered. In this paper, the environmental impacts of the COVID-19 nucleic acid diagnostics were assessed by following a full cradle-to-grave life-cycle approach. The corresponding life-cycle anthology was established to provide quantitative analysis. Moreover, three alternative scenarios, i.e., material substitution, improved waste treatment, and electric vehicle (EV)-based transportation, were further proposed to discuss the potential environmental mitigation and conservation strategies. It was estimated that the life cycle of a single COVID-19 nucleic acid diagnostic test in China would lead to the emission of 612.9 g CO

This study assessed the potential impact of climate change on spatiotemporal distribution of blue and green water resources in the Beijiang River basin, southern China, using the SWAT hydrological model and CORDEX-EAS regional climate models (RCMs). The outputs of three RCMs (namely RMOH, RMPI and RNCC) under two emission scenarios (RCP 2.6 and RCP 8.5) were bias-corrected by using the quantile delta mapping method for the control (1975–2004), near future (2021–2050) and far future (2061–2090) periods. Driven by the corrected climate variables, future blue and green water were assessed by using the SWAT model calibrated with streamflow data. The results indicated that the green water flow in the northwest basin predicted by RMOH under RCP 2.6 would increase up to about 2.7% in 2061–2090; RNCC suggests that most of the basin would experience the most significant reduction in green water storage (over 30%) under RCP 8.5 in the far future. For blue water, the ensemble mean of three RCMs indicates a slight decreasing trend in the northern part of the basin and an increasing one in the southern part under RCP 8.5 in the far future. Our findings could help watershed managers evaluate future hydrological risks and design appropriate adaptation strategies. Ministry of Education (MOE) Published version This work was supported by the National Natural Science Foundation of China (52009022) and AcRF Tier 1 project (2019- T1-001-160) from the Ministry of Education (MOE), Singapore.

The rapid expansion of aquaculture in coastal areas is typically associated with ecological negligence and low water quality owing to the economic exploitation of these areas. However, evaluation of these water bodies tends to be laborious, time-consuming, and costly. Therefore, to overcome the limitations of field surveys, in this study, we evaluated the water quality of the cultured water in the Beibu Gulf of Guangxi, obtained spectral reflectance by unmanned aerial vehicle with multispectral sensors, and constructed inverse models of 11 water quality parameters, namely, ammonia nitrogen (NH3-N), chemical oxygen demand (COD), active phosphate (PO4−), dissolved oxygen, nitrate nitrogen (NO3-N), nitrite nitrogen (NO2-N), inorganic nitrogen, total nitrogen, total phosphorus, suspended solids (SS), and chlorophyll a (chl-a), based on the partial least squares method to invert the water quality distribution of regional aquaculture. Furthermore, we compared the retrieval accuracy of different water quality parameters. The following results were obtained: 1) the constructed model’s results showed that the retrieval models for COD, NO3-N, SS, and chl-a had better accuracy compared with those of other parameters; 2) application of the model to the validation set data yielded a correlation coefficient of 0.93 between the measured and predicted SS values, with a mean absolute error of prediction of 4.65 mg L−1; this parameter constructed the best prediction model. According to the validation set results, the correlation coefficients of chl-a, COD and NO3-N are all greater than 0.8, which had better performance effects compared with the remaining models, which are 0.87, 0.86, and 0.81 respectively. This study provides a reference for remote sensing monitoring of water quality in mariculture in cloudy and rainy areas.

Water, energy, and food are indispensable resources for regional social and economic development. The cross-regional resource transfer can increase the complexity in the coordinated management of water, energy, and food in Guangdong, Hong Kong, and Macao regions. This study proposed a footprint accounting framework for cross-regional water, energy, and food nexus, which incorporates direct flows within territory and nexus flows embodied in final consumption. An environmentally extended multi-regional input-output model was established to quantify water, energy, food, water-related energy, food-related energy, energy-related water, and food-related water footprints in Guangdong, Hong Kong, and Macao regions. The results indicated that direct energy footprint was 5.3 times of food-related and water-related energy footprints, and energy-related and food-related water footprints were 3.8 times of direct water footprint. Inter-regional trade plays an important role in the management of the water, energy, and food nexus in three regions. Hong Kong and Macao outsource huge water, energy, and food nexus footprints by importing freshwater, electricity, and food from Guangdong to satisfy local demand. The proposed footprint framework could serve as indicators or tools for measuring sustainable development goals, and the results could provide the basis for the coordinated resources management of Guangdong, Hong Kong, and Macao regions.

High-strength alterations in the water level due to extreme climate change and increased anthropogenic activities have implications for methane (CH4) and carbon dioxide (CO2) emission variations in shallow lakes. However, the consistency of the carbon emission flux in response to water-level fluctuations and temperature is still unclear. Here, we evaluated the water depth (WD) on the magnitude and variation sensitivity of CH4, CO2, and GHG, and then the temperature dependence of carbon emissions was estimated at different water levels. The water depth threshold indicated a maximum CH4 (97.5 cm) and CO2 (10 cm), resulting in a water depth threshold of GHG at 54.6 cm. Inside the whole WD, the effect of rising water depth on CH4, CO2 and GHG sensitivity shifted from a positive effect to a negative effect at a WD of 97.5 cm. And CH4, CO2 and GHG in 10 cm4 and CO2 are driven by the hydrological regime without water level stress, shifting the GHG emission flux. Ensuring the restoration management goal related to the carbon peak by governing the time of threshold occurrence is essential.

Dam construction and nutrient enrichment are two pervasive stressors in rivers worldwide, which trigger a sharp decline in biodiversity and ecosystem services. However, the interactive effects of both stressors on multitrophic taxonomic groups remain largely unclear. Here, we used the multitrophic datasets captured by the environmental DNA (eDNA) approach to reveal the interactions between dams and nutrient enrichment on aquatic communities from the aspects of taxonomic α diversity, β diversity, and food webs. First, our data showed that dams and nutrient enrichment jointly shaped a unique spatial pattern of aquatic communities across the four river systems, and the dissimilarity of community structure significantly declined (i.e., structural homogenization) under both stressors. Second, dams and nutrients together explained 40-50% of the variations in aquatic communities, and dams had a stronger impact on fish, aquatic insects, and bacteria, yet nutrients had a stronger power to drive protozoa, fungi, and eukaryotic algae. Finally, we found that additive, synergistic, and antagonistic interactions of dams and nutrient enrichment were common and coexisted in river systems and led to significantly simplified aquatic food webs, with decreases in modularity (synergistic) and robustness (additive) and an increase in coherence (synergistic). Overall, our study highlights that eDNA-based datasets can provide multitrophic perspectives for fostering the understanding of the interactive effects of multiple stressors on rivers.

The impact of waves on the morphological changes of sheltered mudflats is less well studied compared to that on open flats. To investigate the sensitivity of low-energy sheltered mudflats to hydrodynamics such as waves, we carried out in situ measurements of bed level, currents, and waves on the middle flat of a sheltered mudflat in a bay in southern China. Two 1-month measurements, March 26–26 April 2021, and July 8–8 August 2021, were performed for repetition. We found that the sheltered system was not as stable as it appeared. The maximum intratidal bed-level variation, ΔZ, was Z reaching up to 2 cm. Intratidal bed-level change patterns depend on the relative dominance of waves and currents: low τc (current-induced bed shear stress) and high τw (wave-induced bed shear stress) promote the generation and migration of bed ripples; comparable τc and τw, with medium-to-high values, lead to non-cyclic bed-level change patterns; high τc and high τw result in bed accumulation/degradation superimposed by bed ripple migration. From a long-term perspective, i.e. in the time scale of month to year, sheltered mudflats are stable systems, and their high sensitivity causes short-term significant bed-level variation. The sensitivity and stability of sheltered mudflats must be further investigated to explore the effects of human intervention and global climate change.

In this study, a new concept concerning comprehensive characteristics of water resources utilization as an index for risk modeling within the water allocation management model is proposed to explore the tolerance of unbalanced allocation problem under the water–energy nexus. The model is integrated with interval two-stage stochastic programming for reflecting system uncertainties. These uncertainties are associated with the industrial production feature and the decision-making process. With respect to the water–energy nexus, energy proposed is mainly focused on the consumption intensity of water purification and transportation from different water sources. The developed model is applied for industrial water resources allocation management in Henan province, China. Multiple scenarios related to disparate energy consumption control and the comprehensive risk levels are simulated to obtain a reasonable trade-off among system profit, comprehensive risk, and energy consumption. The results indicated that the strict comprehensive risk management or energy consumption control measures could cause damage to system benefit owing to decreasing the flexibility of industrial water resources distributions, and the preliminary energy consumption or the comprehensive risk control would be beneficial to moderate the conflict between industrial sectors and water resources, and accelerate industrial structure transformation in the future. HIGHLIGHTS A comprehensive risk-oriented industrial water resources management model is proposed.; Uncertainties are reflected as stochastic and interval information.; Energy–water nexus is a constraint index for water purification and transportation.; The tolerance of unbalanced allocation problem is explored.; Trade-off among system profit, comprehensive risk, and energy consumption is analyzed.

Vegetation in hot and arid valleys is a crucial indicator of ecosystem health, but is vulnerable to human activities and environmental change. Using the Longkaikou Reservoir in the Jinsha River in southwestern China as a case study, we developed a spatially explicit model that combined the plant growth, fruiting, seed dispersal, and seed germination stages to reveal the potential impact of multiple human activities (reservoir construction, logging, grazing, and aerial seeding) on the vegetation dynamics of Dodonaea viscosa and Pinus yunnanensis. After reservoir construction, the grassland area of 68 km2 in 2003 decreased to 24 km2 in 2018, replaced by forest, shrubland, and bodies of water, and the precipitation increased during the dry season, which indicated the improvement of the local plant and soil environment. Our model predicted that when soil moisture decreased by more than 20% compared to current levels, the area of D. viscosa increased greatly at low elevations; however, when at higher soil moisture, P. yunnanensis would occupy more of the study area. Logging and grazing would slightly change the spatial pattern of vegetation and delay P. yunnanensis communities from achieving stability by directly reducing plant biomass. Countermeasures such as aerial seeding would increase the total area by 13.13 km2 and 8.09 km2 of two plants, respectively, and accelerate the stabilization of plant communities. The effects of multiple human activities on vegetation may counteract each other; for example, logging decreased the P. yunnanensis area whereas aerial seeding increased it, and plant biomass changed in response to this pressure. Given the complex relationships between vegetation and human impacts, our study provides a scientific basis for vegetation restoration and ecological security in this hot and arid valley.

Coastal sediments are considered as hotspots of microplastics (MPs), with substantial MPs stocks found in blue carbon habitats such as mangroves and tidal marshes, where wave-damping vegetation reduces sediment erosion and enhances accretion. Here, we examined the effects of such bio-geomorphic feedbacks in shaping MPs burial, through a year-round field study in a mangrove habitat along the coast of South China. The results revealed that MPs abundance decreased significantly with the increase of cumulative sediment erosion as the strength of bio-geomorphic feedbacks declined. More shapes and colors of MPs were found at locations with weaker waves and less sediment erosion, where the average particle size was also higher. Our findings highlight the importance of bio-geomorphic feedbacks in affecting both the abundance and characteristics of the buried MPs. Such knowledge extends our understanding of MPs transport and burial from the perspective of bio-geomorphology, which is essential to assess and predict MPs accumulation patterns as well as its impacts on ecosystem functioning of the blue carbon habitats.

Metronidazole (MNZ), an antibiotic that is specifically used for the treatment of anaerobic infections, may inhibit anaerobic fermentation. This work was designed to understand the fate and effects of MNZ in mesophilic fermentation (MF) and thermophilic fermentation (TF), respectively. The results showed that the removal of MNZ mainly occurred via biodegradation, rather than adsorption, and that MNZ could be completely degraded by opening the imidazole ring. MFs were more strongly inhibited by MNZ than TFs. MNZ concentration increased from 0 to 25 mg/L, hydrogen yield (HY) decreased from 167.5 to 16.8 mL/g glucose (90.0% decrease), and butyrate yield almost completely disappeared in MFs, whereas in TFs, HY decreased only from 101.1 to 89.3 mL/g glucose (11.7% decrease), and ethanol yield increased by 39.8%. Illumina MiSeq sequencing analysis showed that MNZ reduced the abundance of hydrogen-producing bacteria. Furthermore, the inhibition of MNZ on anaerobic fermentation was reversible.

With the intensification of climate change and human activities, the watershed ecosystem is seriously fragmented, which leads to the obstruction of hydrological connectivity, and further causes the degradation of the ecosystem. As the value of wetlands continues to be exploited, hydrological connectivity becomes increasingly significant. In this paper, the characteristics and development of hydrological connectivity research from 1998 to 2018 were analyzed through the scientometric analysis based on Web of Science database. CiteSpace, an analytical software for scientific measurement, is used to visualize the results of the retrieval. The analysis results of co-occurrence, co-operative and co-cited network indicate that the hydrological connectivity is a multidisciplinary field which involves the Environment Science and Ecology, Water Resources, Environmental Sciences, Geology and Geosciences. According to Keyword cooccurrence analysis, ecosystem, floodplain, dynamics, climate change and management are the main research hotspots in each period. In addition, the co-cited analysis of references shows that “amphibians” is the largest cluster of hydrological connectivity, and the “channel network” is the most important research topic. It is worth noting that the “GIWS” (Geographically Isolated Wetlands) is the latest research topic and may be a major research direction in the future.

Aerated flow characterized by complex mass transfer processes with multiple hydraulic properties is a common enviro-hydraulics phenomenon, which have a variety of profound effects on aquatic ecosystems and the environment. Accurate prediction of the mass transfer process between air and water is crucial to manage the water ecosystem. In this research, an improved two-phase mass transfer smoothed particle hydrodynamics (ITMT-SPH) model is developed with considering the inherent hydrodynamic equations and transport equations to investigate multiple key factors that have ecological implications such as DO (dissolved oxygen) concentration and TDG (total dissolved gas) level. The established model can eliminate the effects of phase separation and non-physical voids for conventional SPH models, which performs better than conventional grid-based methods in terms of prediction accuracy of hydraulic calculation. In addition, to improve the prediction accuracy of mass transfer calculation, experimental and observed field data from a physical model and a practical project are used to calibrate the source parameter of transport equations. Then, a physical model of Songta Hydropower Station (1:80) is established to simulate DO concentration. At the same time, the practical project of Tongjiezi Hydropower Station is used to explore dynamics of TDG level. Simulation results show that ITMT-SPH can simulate ecological indicators of the aerated flow well. The maximum relative error of DO deficit recovery rate between simulation and experiment is 7.8% downstream of dam of Songta physical model. The predicted result of TDG level downstream of Second Dam is 130–148% for Tongjiezi Project, which is close to the monitoring result (138%). This work provides an important theoretical and technical support for the application of ITMT-SPH model to accurately simulate ecological indicators in the ecosystem management.

Traditional blue water resources assessment and management may not meet the needs of sustainable water resource utilization; ignoring the number of green water resources will underestimate the availability of water resources. To rationally allocate and scientifically manage the limited water resources, it is necessary to divide the rich and poor flow situation of blue water and green water. The MIKE SHE-MIKE HYDRO integrated coupled model was selected and used in the Yalong River basin to ascertain the blue and green water in the hydrological cycle. The model was calibrated by matching simulated discharge against observed streamflow discharge at the Tongziling Station. At the same time, the research analyzed the component of green water and the total amount of blue water or green water on a temporal scale. The set pair analysis (SPA) was introduced to classify blue water and green water, which can not only understand the amount and distribution characteristics of water resources in the Yalong River Basin but also rationally allocate the total of water resources in the basin from the perspective of the regional water cycle. Furthermore, according to the situation of blue water and green water in the basin, the related policies are formulated to realize the efficient utilization of water resources in the Yalong River basin.

Understanding the changes in hydrological process is a key subject for water resource management of a high-diversity watershed. In this paper, through an establishment of a SWAT-based model, the effects of climate change and its induced vegetation change on hydrological process were analyzed in the East River Basin. The model could well simulate the hydrological processes of the basin including surface runoff (SURQ), groundwater (GWQ), lateral flow (LATQ), total water yield (WYLD), actual evapotranspiration (ET), and groundwater recharge (PERC). Under the vegetation change induced by temperature increase, the effects of the vegetation change on hydrological process were larger than that of the temperature change. Under the vegetation change caused by the increase of temperature and precipitation, the vegetation change enhanced the effects of climate change on annual SURQ, LATQ, GWQ, WYLD, and PERC of the basin. Under spatial scale, when the temperature and precipitation changed simultaneously, the increase of precipitation could promote the increase of annual ET in sub-watersheds. Also, the annual SURQ, WYLD, GWQ and ET in western sub-watersheds were more sensitive to the cumulative changes of vegetation and climate. This work can provide useful information to decision makers in water resource management of watersheds.

As the total water resources consumption control and carbon mitigation continuous improvement, the weak water-carbon incorporate management is increasingly exposed. In this study, a water-carbon nexus assessment framework is proposed to analyze the nexus relationship between water consumption and carbon emission, and distinguishes the coupled water-carbon transmission intensity and the transfer paths under regional and industrial scales. According to the practical input-output table, water consumption, and carbon emission information, the framework is applied to Beijing-Tianjin-Hebei urban agglomeration (BTHUA), a population, resource, and trade intensive area of China. Inter-regional/intra-regional water consumption and carbon emission transfer fluxes between sectors, the pairwise ecological relationship, and the water-carbon nexus were analyzed. Results indicated that the water-carbon transfer indexes from Hebei to Beijing and Tianjin were 161.85 kg/m

Land use classification is fundamental both for monitoring and predicting regional development patterns and for planning and regulating land use. This research proposed a joint probability-based classifier for land use classification of multispectral remote sensing data and applied it to the Lake Baiyangdian region of North China. This classifier, based on the vine copula method, was suitable for dealing with the uncertainties of land classification and its random variables that did not necessarily obey predefined distributions. Comparison of the results obtained using the proposed classifier with those derived using the widely used maximum likelihood classifier indicated that the accuracy of land use classification of multispectral remote sensing data was higher with the proposed classifier. Compared with the contingency matrix of the maximum likelihood classifier, that of the vine copula classifier showed an increase in the producer’s (user’s) accuracy of rural land (shallow water) of 29.4% (30.0%). The proposed classifier increased the shallow water area and significantly reduced the area of rural land. The main reason was the maximum likelihood classifier had poor classification performance, misclassifying pixels of shallow water as rural land. The findings of this study demonstrated that the vine copula classifier performs better than the traditional maximum likelihood classifier and that its application could promote full utilization of remotely sensed data.

Flood disasters are one of the most destructive hazards faced across the globe, and thus flood hazard analysis is an essential factor for flood management. Due to the randomness and fuzziness of flood hazard, a series of possibilities is required for a certain flood level rather than just one exact probability. As a method for fuzzy hazard analysis derived from the information diffusion theory, the Interior-Outer-Set Model (IOSM) has the potential to reflect the randomness and fuzziness of flood hazard, however, the controlling intervals might have no sample points particularly when there are extraordinarily large flood peak flows or the flood samples concentrate. Based on this, the current study proposes a new framework for flood hazard analysis. First, flood samples are extracted from daily observed peak flow data. Second, the traditional IOSM is improved using design peak flows from flood frequency analysis (FFA) as the controlling points. From this, probability and floods hazard values are estimated via the FFA based IOSM (FFA-IOSM).The proposed framework is applied using data from the Dongjiang River, South China. Results demonstrate that the estimated flood probability was able to more effectively reflect the randomness and fuzziness of flood hazard compared to the traditional IOSM. This study provides a basis for reasonable flood engineering practices and supports the government with effective guidance on flood risk management, particularly under the increasing frequencies of the extreme precipitation events.

An improved model for investigating dual effects of vegetation density variations and groundwater level fluctuations on water transport and dissipation in the soil-plant-atmosphere continuum (SPAC) of raised field wetlands was developed through combining the HYDRUS and the dual crop coefficient models. The results showed the following: (1) the improved model was reliable for soil water and evapotranspiration simulation. For soil water, the coefficient of determination (R2) was above 0.68, the Nash-Sutcliffe efficiency coefficient (NSE) was above 0.53, and the relative deviation (Re) was below 6%. For evapotranspiration, R2, NSE and Re were 0.83, 0.83 and 12.3%, respectively. (2) For the evapotranspiration, both vegetation densities variations and groundwater level fluctuation would affect it. (3) For 0%–60% density, the groundwater level fluctuation mainly contributed to changes in evaporation rather than transpiration. For 80%–100% density, it was transpiration. (4) For the soil water supplement and drainage, under different densities, the main water replenishment source in the same month was almost identical, but the main water drainage approach was inconsistent. (5) For the soil water balance, groundwater level fluctuations had an influence on it, while vegetation density variations did not. This study can provide an method for analyzing water transport in SPAC.

Three new species of Meleonoma Meyrick, 1914 (Gelechioidea, Xyloryctidae) from China, Yunnan Province, Meleonoma plicatasp. nov., M. scalpratasp. nov. and M. taeniatasp. nov., are described and illustrated. A key to Meleonoma species known from China is provided.

Response of water and sediment generation to climate change and anthropogenic activities is becoming a hot topic in the middle reach of the Jinsha River Basin. In this research, coefficients of variation and concentration degree (i.e., Cᵥ and Cd) and double mass curve (DDC) were adopted to examine the changes in water and sediment discharge and their relationships with precipitation. The contribution rates of climatic and anthropogenic factors to water and sediment discharge were assessed through comparisons between the measured and predicted values in the baseline and postbaseline periods in the basin. The main results were: (a) the water and sediment discharges of the basin showed a decreasing trend from 2006 to 2014, with peak points of Cᵥ and Cd of sediment discharge of the basin in 2009 and 2010, respectively; (b) the precipitation had a major influence on water discharge variations, and the peak point of the DDC of the cumulative precipitation and sediment discharge was consistent with the cumulative water and sediment discharge; and (c) under annual and flooding season scales, the contribution rates of anthropogenic factors to water discharge were 63.060% and 70.457%, respectively. The contribution rates of anthropogenic factors on sediment discharge were 84.790% and 85.541%, respectively. The impacts of anthropogenic factors on water and sediment discharge were more significant than the impacts of precipitation, in which the construction and operation of cascade hydropower stations (CHS) were believed to play a crucial role.

Polyketide synthase 13 (Pks13), an essential enzyme for the survival of

Coastal sediments, recognized as a major sink for microplastics (MPs), are subject to frequent physical disturbances, such as wave disturbance and associated sediment dynamics. Yet it remains poorly understood how wave disturbance regulates MPs accumulation in such a dynamic environment. Here, we examined the effects of waves and their interactions with material density and burial depth on the retention of MPs in coastal sediments, through manipulative experiments in a mangrove habitat along the coast of South China. The results clearly revealed that stronger waves removed more buried MPs from the sediments. Moreover, storms can have disproportional effects on MPs retention by inducing large waves and strong sediment erosion. We also demonstrated that MPs retention generally increased linearly with growing material density and non-linearly with raised burial depth in the sediment. Overall, our findings highlight the importance of both external and internal factors in shaping MPs retention in coastal ecosystems like mangroves, which is essential to assess and predict MPs accumulation patterns as well as its impacts on ecosystem functioning of such blue carbon habitats.