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Chloride is one of the most abundant ions in sea water, which is more available than fresh water. Due to lack of H2O adsorbate states near the valence band maximum (VBM) edge, the difficulty of water dissociation incidents has been reported on the rutile TiO2 surface as the excitation energy is around the band gap energy of TiO2. It is interesting whether the extra chloride can be a benefit to the water dissociation or not. In this study, the models of chlorine adatoms placed on the rutile TiO2 (110)/water interface are constructed using ab initio methods. The time-dependent spatial charges, bond-lengths of water molecules, and Hirshfeld charges are calculated by real-time time-dependent density functional theory and the Ehrenfest dynamics theory for investigating the excited state nonadiabatic dynamics of water dissociation. This study presents two photoinduced water-splitting pathways related to chlorine and analyzes the photogenerated hole along the reactions. The first step of water dissociation relies on the localized competition of oxygen charges between the dissociated water and the bridge site of TiO2 for transforming the water into hydroxyl and hydrogen by photoinduced driving force.

Roughly half of the human population lives near the coast, and coastal water pollution (CWP) is widespread. Coastal waters along Tijuana, Mexico, and Imperial Beach (IB), USA, are frequently polluted by millions of gallons of untreated sewage and stormwater runoff. Entering coastal waters causes over 100 million global annual illnesses, but CWP has the potential to reach many more people on land via transfer in sea spray aerosol (SSA). Using 16S rRNA gene amplicon sequencing, we found sewage-associated bacteria in the polluted Tijuana River flowing into coastal waters and returning to land in marine aerosol. Tentative chemical identification from non-targeted tandem mass spectrometry identified anthropogenic compounds as chemical indicators of aerosolized CWP, but they were ubiquitous and present at highest concentrations in continental aerosol. Bacteria were better tracers of airborne CWP, and 40 tracer bacteria comprised up to 76% of the bacteria community in IB air. These findings confirm that CWP transfers in SSA and exposes many people along the coast. Climate change may exacerbate CWP with more extreme storms, and our findings call for minimizing CWP and investigating the health effects of airborne exposure.

Water splitting is an effective strategy to produce renewable and sustainable hydrogen energy. Especially, seawater splitting, avoiding use of the limited freshwater resource, is more intriguing. Nowadays, electrocatalysts explored for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using natural seawater or saline electrolyte have been increasingly reported. To better understand the current status and challenges of the electrocatalysts for HER and OER from seawater, we comprehensively review the recent advances in electrocatalysts for seawater splitting. The fundamentals, challenges and possible strategies for seawater splitting are firstly presented. Then, the recently reported electrocatalysts that explored for HER and OER from seawater are summarized and discussed. Finally, the perspectives in the development of high-efficient electrocatalysts for seawater splitting are also proposed.

Seagrass meadows provide valuable ecosystem services of coastal protection and chemical habitat formation that could help mitigate the impact of sea level rise and ocean acidification. However, the intensification of hydrodynamic forces caused by sea level rise, in addition to habitat degradation threaten the provision of these ecosystem services. With quantitative field measurements of the coastal protection and chemical habitat formation services of seagrass meadows, we statistically model the relationships between hydrodynamic forces, vegetation density and the provision of these ecosystem services. Utilising a high-resolution hydrodynamic model that simulates end of the century hydrodynamic conditions and three scenarios of coral reef degradation (i.e., keep up, remain or loss) we quantify how the environmental conditions within a tropical bay will change given changes to the provision of ecosystem services. Our study shows that increasing hydrodynamic forces lead to a seafloor made up of a larger grain size that is increasingly unstable and more vulnerable to erosion. The loss of a fringing reef leads to larger hydrodynamic forces entering the bay, however, the 0.87 m increase in depth due to sea-level rise reduces the bed shear stress in shallower areas, which limits the change in the ecosystem services provided by the current benthic seagrass meadow. Loss of seagrass constitutes the greatest change in a bay ecosystem, resulting in the sediment surface where seagrass existed becoming unstable and the median sediment grain size increasing by 5-7 %. The loss of seagrass also leads to the disappearance of the unique fluctuating chemical habitat, which leaves the surrounding community vulnerable to ocean acidification. A reduction or complete loss of these ecosystem services would impact the entire community assemblage while also leaving the surrounding coastline vulnerable to erosion, thus exacerbating negative effects brought about by climate change.

A hybrid enhanced oil recovery (EOR) method by combining low salinity water (LSW) and low salinity surfactant (LSS) flooding techniques was designed. Different experiments were done to screen the Caspian seawater (SW) with altered ionic composition and surfactant, for the optimized performance in Kazakhstani carbonate oil fields. Changing to a more water-wet state and creating the middle phase were studied as the main criteria to select the best-engineered brine and anionic surfactant. The largest alteration towards the water-wet condition was recorded at 10 times dilution of the SW with 3- and 6- times spiked calcium and sulfate ions, respectively (10xSW-6SO4, Mg, 3Ca). This combination of anionic surfactants with carbonate formations is considered as a new approach in hybrid EOR methods. Among the anionic surfactants screened, Soloterra-113H (Alkyl Benzenesulfonic acid) showed the best solubilization ratio, aqueous stability, and Winsor type 3 microemulsions. The wettability alteration by the combination of optimized brine and screened surfactant was greater compared to the standalone LSW, which was confirmed by the 10° difference in contact angle measurement. The microemulsion phase constituted nearly 40% of the total height of the oil/brine column by the hybrid method. The recovery factor after injecting formation water was 52%, and it increased to 61% after optimized LSW injection. After switching to the engineered brine/surfactant, the recovery factor reached 70%, which proves the effectiveness of the hybrid method. The proposed combined method works better than either standalone EOR method due to the higher alteration in capillary number by changing wettability and reducing IFT, which leads to higher oil recovery.

Red abalone, Haliotis rufescens, are herbivorous marine gastropods that primarily feed on kelp. They are the largest and longest-lived of abalone species with a range distribution in North America from central Oregon, United States, to Baja California, MEX. Recently, red abalone have been in decline as a consequence of overharvesting, disease, and climate change, resulting in the closure of the commercial fishery in the 1990s and the recreational fishery in 2018. Protecting this ecologically and economically important species requires an understanding of their current population dynamics and connectivity. Here, we present a new red abalone reference genome as part of the California Conservation Genomics Project (CCGP). Following the CCGP genome strategy, we used Pacific Biosciences HiFi long reads and Dovetail Omni-C data to generate a scaffold-level assembly. The assembly comprises 616 scaffolds for a total size of 1.3 Gb, a scaffold N50 of 45.7 Mb, and a BUSCO complete score of 97.3%. This genome represents a significant improvement over a previous assembly and will serve as a powerful tool for investigating seascape genomic diversity, local adaptation to temperature and ocean acidification, and informing management strategies.

This study explored the applicability of chemical cleaning and air-backwash to alleviate biofouling on seawater membrane distillation (SWMD). Membrane performance and wettability properties maintained at optimum duration and frequency of the treatments, as indicated by low permeate conductivity throughout the tests. The cleaning of the membrane using 2% NaOH by immersing the membrane for 30 min after 240 min operation removed the biofouling layer, indicated by low permeate conductivity of 370 µScm

A novel bacterium designated RR4-40

Ocean acidification (OA) is expected to modify the structure and function of coral reef ecosystems by reducing calcification, increasing bioerosion, and altering the physiology of many marine organisms. Much of our understanding of these relationships is based on experiments with static OA treatments, although evidence suggests that the magnitude of diurnal fluctuations in carbonate chemistry may modulate the calcification response to OA. These light-mediated swings in seawater pH are projected to become more extreme with OA, yet their impact on bioerosion remains unknown. We evaluated the influence of diurnal carbonate chemistry variability on the bioerosion rates of two Caribbean sponges: the zooxanthellate Cliona varians and azooxanthellate Cliothosa delitrix. Replicate fragments from multiple colonies of each species were exposed to four precisely controlled pH treatments: contemporary static (8.05 ± 0.00; mean pH ± diurnal pH oscillation), contemporary variable (8.05 ± 0.10), future OA static (7.80 ± 0.00), and future OA variable (7.80 ± 0.10). Significantly enhanced bioerosion rates, determined using buoyant weight measurements, were observed under more variable conditions in both the contemporary and future OA scenarios for C. varians, whereas the same effect was only apparent under contemporary pH conditions for C. delitrix. These results indicate that variable carbonate chemistry has a stimulating influence on sponge bioerosion, and we hypothesize that bioerosion rates evolve non-linearly as a function of pCO

The safety of mooring systems and accessories is one of the most critical issues in the structural integrity of floating oil/gas and renewable offshore structures. Mooring chains and accessories operate under dynamic conditions in harsh marine environments. They are subject to severe wear and corrosion between their links due to relative movement from waves, wind, and ocean currents that disrupt structural integrity. To cope with this problem, the pack-aluminizing process was applied on the R4 grade offshore mooring chain steel for 2 h at 850 °C to improve corrosion and wear-corrosion (tribocorrosion) resistance in 3.5% NaCl. The tribocorrosion behaviour of untreated and aluminized samples was investigated by a tribo-electrochemical setup that simultaneously allows for collecting the wear and corrosion data. Potentiodynamic and potentiostatic corrosion and tribocorrosion tests were carried out to understand corrosion kinetics. Optical, SEM, XRD and EDS analyses were performed to characterize the aluminide layer and surface morphologies before and after tribocorrosion investigations. In polarization scans under corrosion and tribocorrosion conditions, the current showed a significant activation stretch of several orders of magnitude, with minor potential changes in the anodic region. Due to the galvanic effects of sliding under natural electrochemical conditions, the untreated R4 alloy exhibited cathodic properties in the wear track, while the aluminium coating was out of the wear track due to its oxide-forming ability. At the cathodic potential, two hard Al2O3 materials under pure mechanical effects and third bodies emerging from cracks on the coating surface increase the friction coefficient (COF), while the oxide product film, which has a lubricating ability and pits which reduces the contact area, caused a decrease in COF at the high anodic potential. The study revealed that while the aluminide layer improved the corrosion and tribological character of R4 alloy, material loss from wear track increased due to micro fractures and cracks in the coating layer during sliding tribocorrosion conditions.

In microbiology, cultivation is a central approach for uncovering novel physiology, ecology, and evolution of microorganisms, but conventional methods have left many microorganisms found in nature uncultured. To overcome the limitations of traditional methods and culture indigenous microorganisms, we applied a two-stage approach: enrichment/activation of indigenous organisms by using a continuous-flow down-flow hanging sponge bioreactor and subsequent selective batch cultivation. Here, we provide a protocol for this bioreactor-mediated technique using activation of deep marine sediment microorganisms and downstream isolation of a syntrophic co-culture containing an archaeon closely related to the eukaryote ancestor (Candidatus Promethearchaeum syntrophicum strain MK-D1) as an example. Both stages can easily be tailored to target other environments and organisms by modifying the inoculum, feed solution/gases, attachment material and/or cultivation media. We anaerobically incubate polyurethane sponges inoculated with deep-sea methane seep sediment in a reactor at 10 °C and feed anaerobic artificial seawater medium and methane. Once phylogenetically diverse and metabolically active microorganisms are adapted to synthetic conditions in the reactor, we transition to growing community samples in glass tubes with the above medium, simple substrates and selective compounds (e.g., antibiotics). To accommodate for the slow growth anticipated for target organisms, primary cultures can be incubated for ≥6-12 months and analyzed for community composition even when no cell turbidity is observed. One casamino acid- and antibiotic-amended culture prepared in this way led to the enrichment of uncultured archaea. Through successive transfer in vitro combined with molecular growth monitoring, we successfully obtained the target archaeon with its partner methanogen as a pure syntrophic co-culture.

Our understanding of the significance of dimethylmercury (DMHg) to the mercury (Hg) global ocean biogeochemical cycle is unclear because of the lack of detailed DMHg measurements in the water column. To our knowledge, 30 years of published studies have generated no more than 200 DMHg data points in the ocean surface waters and marine boundary layer (MBL). To improve the precision and reduce the uncertainty in determining DMHg in surface seawater, we developed a simple and robust DMHg automatic analyzer (DAA). This DAA system couples the main sampling and analytic steps, including a continuous flow chamber, with dual Carbotrap preconcentration, a gas chromatographic column, a cold vapor atomic fluorescence spectrometry, and a data logger for signal integration. We compared the operation, performance, and reproducibility between our DAA and the traditional manual analytic method. Its advantages include the ease of operation, the high time resolution and precision (30 min sampling and5% relative variation), and long-term stability (2 weeks). The DAA can determine DMHg in both the MBL and surface seawater. The estimated detection limits for DMHg with the DAA in the atmosphere and in surface seawater are 10 pg/m

Originally developed for use in controlled laboratory settings, potentiometric ion-selective electrode (ISE) sensors have recently been deployed for continuous, in situ measurement of analyte concentration in agricultural (e.g., nitrate), environmental (e.g., ocean acidification), industrial (e.g., wastewater), and health-care sectors (e.g., sweat sensors). However, due to uncontrolled temperature and lack of frequent calibration in these field applications, it has been difficult to achieve accuracy comparable to the laboratory setting. In this paper, we propose a novel temperature self-calibration method where the ISE sensors can serve as their own thermometer and therefore precisely measure the analyte concentration in the field condition by compensating for the temperature variations. We validate the method with controlled experiments using pH and nitrate ISEs, which use the Nernst principle for electrochemical sensing. We show that, using temperature self-calibration, pH and nitrate can be measured within 0.3% and 5% of the true concentration, respectively, under varying concentrations and temperature conditions. Moreover, we perform a field study to continuously monitor the nitrate concentration of an agricultural field over a period of 6 days. Our temperature self-calibration approach determines the nitrate concentration within 4% of the ground truth measured by laboratory-based high-precision nitrate sensors. Our approach is general and would allow battery-free temperature-corrected analyte measurement for all Nernst principle-based sensors being deployed as wearable or implantable sensors.

The solar-driven interfacial evaporation (SDIE) is now a promising way to solve the shortage of fresh water. However, high performance SDIE for the oil contaminated seawater remains challenging. Here, we propose a facile "chitosan assisted MXene decoration" strategy to prepare a superhydrophilic and underwater superoleophobic Chitosan/MXene/fabric (CMF) for highly efficient SDIE. Benefiting from the superhydrophilicity and excellent photo-thermal conversion performance, the CMF is served as both the solar absorber and the water transportation path. Under the light illumination with one sun intensity (1 kW·m

Electrochemical splitting of seawater is highly preferable over freshwater electrolysis to produce sustainable hydrogen terrifically due to its abundance in nature. Seawater electrolysis is encouraging to produce green hydrogen and safe drinking water. The accomplishment of seawater electrolysis needs robust and cost-effective anode material that should acquire an excellent catalytic activity, durability, and selectivity for OER and have high resistance against Cl- corrosion. Here we report a free-standing anode consisting of partially amorphous sulfur substituted copper oxide (S-Cu2O-CuO) nanoneedles directly grow on Cu foil. Benefiting from high electrical conductivity, plentiful active sites, high intrinsic activity per active site, and fast rate for ionic and electronic transfer, these disorders nanoneedles structured S-Cu2O-CuO demonstrate outstanding OER performance needing an overpotential of 450 mV to attain a high geometric activity (1000 mA cm−2) in 1 M KOH. Its disordered surface structure and amorphous features lead to improved corrosion resistance and durability, making it a prospective anode for direct seawater electrolysis. It requires an overpotential of 420 mV to achieve a geometric activity of 500 mA cm−2 in alkaline seawater and sustain water electrolysis for 100 h without making hypochlorite. Because of the facile, scalable, and economical approach, the catalyst is highly promising for large-scale realistic alkaline seawater electrolysis.

Aims This work aims to characterize the microbial diversity of the encrusting sponge Cliona varians, a pore-forming and coral reef bioeroding marine sponge of emerging spread related to ocean acidification. Methods and results We analysed the microbiome composition by 16S V4 amplicon next-generation sequencing in a community of the bioeroding coral reef encrusting/excavating marine sponge Cliona varians thriving at the Southern Caribbean Sea. About 87.21% and 6.76% of the sequences retrieved were assigned to the domain Bacteria and Archaea. The most predominant operational taxonomic units were classified as members of the order Rhizobiales and family Nitrosopumilaceae, representing members of not yet characterized genera. Features found strictly conserved in the strain/genomic representatives reported in those microbial taxa are nitrogen fixation and transformation. Conclusion Our results suggest, in accordance with recent results, that these microbiome members and associated functions could be contributing to the biological fitness of the sponge to be able to colonize and bioerode in environments with low access and scarce availability of nitrogen sources. Significance and Impact of Study Coral reefs bioresources such as sponge holobionts are intriguing and complex ecosystem units. This study contributes to the knowledge of how C. varians microbiota is composed or shaped, which is crucial to understand its ecological functions.

The Vibrionaceae family groups genetically and metabolically diverse bacteria thriving in all marine environments. Despite often representing a minor fraction of bacterial assemblages, members of this family can exploit a wide variety of nutritional sources, which makes them important players in biogeochemical dynamics. Furthermore, several Vibrionaceae species are well-known pathogens, posing a threat to human and animal health. Here, we applied the phylogenetic placement coupled with a consensus-based approach using 16S rRNA gene amplicon sequencing, aiming to reach a reliable and fine-level Vibrionaceae characterization and identify the dynamics of blooming, ecologically important, and potentially pathogenic species in different sites of the northern Adriatic Sea. Water samples were collected monthly at a Long-Term Ecological Research network site from 2018 to 2021, and in spring and summer of 2019 and 2020 at two sites affected by depurated sewage discharge. The 41 identified Vibrionaceae species represented generally below 1% of the sampled communities; blooms (up to ~ 11%) mainly formed by Vibrio chagasii and Vibrio owensii occurred in summer, linked to increasing temperature and particulate matter concentration. Pathogenic species such as Vibrio anguilllarum, Vibrio tapetis, and Photobacterium damselae were found in low abundance. Depuration plant samples were characterized by a lower abundance and diversity of Vibrionaceae species compared to seawater, highlighting that Vibrionaceae dynamics at sea are unlikely to be related to wastewater inputs. Our work represents a further step to improve the molecular approach based on short reads, toward a shared, updated, and curated phylogeny of the Vibrionaceae family.

Desalination brine is a hypersaline byproduct that contains various operational chemicals such as polyphosphonate-based antiscalants. Brine often sinks and flows over the seabed by density currents; therefore, it may affect sediment-water nutrient fluxes and thus microbial activity. We quantified these parameters in brine plumes around two large-scale desalination facilities located in the P-limited Southeastern Mediterranean Sea. The benthic nutrient fluxes and microbial activity were determined using

Deep-water corals are protected in the seas around New Zealand by legislation that prohibits intentional damage and removal, and by marine protected areas where bottom trawling is prohibited. However, these measures do not protect them from the impacts of a changing climate and ocean acidification. To enable adequate future protection from these threats we require knowledge of the present distribution of corals and the environmental conditions that determine their preferred habitat, as well as the likely future changes in these conditions, so that we can identify areas for potential refugia. In this study, we built habitat suitability models for 12 taxa of deep-water corals using a comprehensive set of sample data and predicted present and future seafloor environmental conditions from an earth system model specifically tailored for the South Pacific. These models predicted that for most taxa there will be substantial shifts in the location of the most suitable habitat and decreases in the area of such habitat by the end of the 21st century, driven primarily by decreases in seafloor oxygen concentrations, shoaling of aragonite and calcite saturation horizons, and increases in nitrogen concentrations. The current network of protected areas in the region appear to provide little protection for most coral taxa, as there is little overlap with areas of highest habitat suitability, either in the present or the future. We recommend an urgent re-examination of the spatial distribution of protected areas for deep-water corals in the region, utilising spatial planning software that can balance protection requirements against value from fishing and mineral resources, take into account the current status of the coral habitats after decades of bottom trawling, and consider connectivity pathways for colonisation of corals into potential refugia.

A novel efficiency reduction model to tubular heat exchanger based on heat transfer losses by biofilm adhesion is proposed, which included a modified equation based on the real data-dependent time, seawater, hydrodynamics and heat transfer resistance using computational fluid dynamics (CFD). The biofilm growth model based on Verhulst model and experimental data has been obtained and simulated in a CFD software tool to analyze the tubular heat exchanger performance prediction cooled by seawater. The biofilm CFD model with appropriate fit, and the correlation coefficient (R2) values are between 0.97 and 0.99, was validated by experimental data obtained at different flow velocity. The final results of in/outlet difference temperatures were from 3.9 °C to 2.2 °C for different flow velocity with R2 gt; 0.97. The simulation results demonstrate that the novel CFD model is capable of predicting the efficiency losses during the development period of biofilm growth in in open-loop cooling seawater systems.

Most previous studies focused on the redox state of the deep water, leading to an incomplete understanding of the spatiotemporal evolution of the redox-stratified ocean during the Ediacaran-Cambrian transition. In order to decode the redox condition of shallow marine environments during the late Ediacaran, this study presents I/(Ca + Mg), carbon and oxygen isotope, major, trace, and rare earth element data of subtidal to peritidal dolomite from the Dengying Formation at Yangba, South China. In combination with the reported radiometric and biostratigraphic data, the Dengying Formation and coeval successions worldwide are subdivided into a positive δ

Microplastics (MPs) are a widely distributed pollutant and have been attracting global attention. The increasing abundance of MPs in marine environments has raised concern about their adverse effects on marine organisms and influence on the fate of contaminants in seawater. In this study, we investigated the effects of natural aging on the adsorption of di (2-ethylhexyl) phthalate (DEHP), one of the most widely used phthalic acid esters (PAEs), in two types of MPs (polyethylene and polystyrene). Biofilm was observed on the surface of MPs after 3-month exposure in seawater. Atomic force microscopy revealed there were significant physical changes in the MPs after aging. Aging in coastal seawater for 3 months significantly reduced the MPs' surface roughness and adhesion, and increased the Young's modulus at the same time. Adsorption isotherms of DEHP indicated that aged MPs had stronger binding capacity of the organic contaminant than pristine MPs. Our data shed some light on the biogeochemical role of MPs in marine environments.

High-frequency field nutrient analyzers offer a promising technology to solve time-consuming and laborious sampling problems in dynamic and complex river-estuarine-coastal ecosystems. However, few studies on the simultaneous underway analysis of five key nutrients (ammonium, nitrite, nitrate, phosphate, and silicate) in seawaters are available because of the limitations of the technique. In this study, a state-of-the-art autonomous portable analyzer for the shipboard analysis of nutrients in the environment of varied salinities and concentration ranges was reported. The analyzer consisted of compact hardware that was well suited for shipboard deployment with minimal maintenance. Moreover, a novel LabVIEW-based software program was developed, containing additional functions such as automated calibration curve generation, autodilution of high-concentration samples, and a user-friendly interface for multiparameter analysis using a single instrument. After the optimization of chemical reactions and work flow chart, the analyzer exhibited low limits of detection, a large linear range with automated dilution, and relative standard deviations of less than 2% (

Infectious diseases caused by Aeromonas salmonicida (A. salmonicida) have a huge impact and produce significant losses in aquaculture and fish farming. Fish pathogen early detection is a critical step for the rapid identification and prevention of these problems. This work presents a novel portable label-free ultrasensitive electrochemical immunosensor for A. salmonicida detection in seawater. It consists of a fluidic integrated electrochemical-cell-chip (ECC) with independent chambers enclosing three electrochemical cells (ECs). Anti-A. salmonicida (AbSalm) antibodies were covalently attached to the gold surface of the microfabricated electrodes and were used for the sensitive detection of A. salmonicida. The antibody-antigen immunoreaction was studied by enzyme-linked immunosorbent assay (ELISA), and the surface functionalization was characterized by using quartz crystal microbalance (QCM), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The performance of the developed immunosensor, in terms of sensitivity, repeatability, and specificity, was also studied. The linear working range varied between 1 and 10

Electrolysis of seawater gets an attention to produce hydrogen for renewable energy technology. It significantly reduces the use of fresh water instead of seawater. Development of low temperature fabrication of electrocatalyst can explore seawater splitting by avoiding chloride reduction during the hydrogen production. In the present work, we fabricated low temperature hydrothermal growth of Cu2S electrocatalyst on Ni foam at constant temperature of 80 °C at different growth times of 1–3 h. The prepared Cu2S electrocatalyst grown for 1 h exhibited low overpotentials of 76 and 118 mV at 10 mA/cm2 (289 and 358 mV overpotentials at 100 mA/cm2) in 1 M KOH deionized water and seawater, respectively for hydrogen evolution reaction (HER). The Tafel plot of Cu2S catalyst grown for 1 h showed lesser Tafel slope value of 128 mVdec−1 than that of other growth times 2 h (136 mVdec−1) and 3 h (142 mV dec−1) indicating elevated electrocatalytic behaviour of Cu2S grown for 1 h. Electrochemical impedance spectroscopy (EIS) showed charge transfer resistance of 12.8Ω, 19.6 Ω and 25.7Ω, for Cu2S grown for 1, 2 and 3 h, respectively, this lower charge transfer resistance indicated higher charge transfer properties. The Cu2S electrocatalyst grown for 1 h sustained retention of 80% after 12 h continuous stability test. Therefore, the cost-effective and low temperature fabrication of Cu2S electrocatalyst proceeds for development of largescale seawater splitting for hydrogen production.

Microplastic pollution is a growing global concern and a serious threat to aquatic life. Microplastics (MPs) have been found in the natural environment in the last few years. However, levels of microplastic pollution in aquaculture areas of Hainan Island have been less studied than in wild environments. Xincun bay (XC) and Gangmen bay (GM) are lagoons that are rich in fishery resources. Here, we investigated microplastic pollution in 8 surface seawater samples, 17 species of fish, and mussel samples from XC bay and GM bay, Hainan, China. The MPs were isolated from surface seawater, organisms and identified by microscopic, Raman spectroscopic and micro-Fourier Transform Infrared spectrometer methods. The mean abundance of MPs in seawater samples was 523 items/m3 and that of fish was 7.1 items/individual and the percentages of microplastics detected in the gastrointestinal tracts (GITs) and gill were 99% and 1%, respectively. MPs were also observed in the soft tissues of mussel samples with a mean abundance of 0.36 ± 0.81 items/individual. Most MPs were identified as polystyrene and their sizes ranged between 0.5 and 5 mm in both seawater and organism samples. Our results indicated that the uptake of microplastics by organisms was closely related to microplastic pollution in the aquaculture environment. Foam pollution is common in organisms and surface seawater in the aquaculture area of our study region, which provides a way for human exposure.

The pollution and adverse effects of microplastics in the marine environment have been widely reported. However, the information on the transfer of chemical additives from microplastics to the environment or organisms is quite limited. This study investigated the release of hexabromocyclododecanes (HBCDs) from expanded polystyrene (EPS) microplastics in seawater and digestive fluids. The results showed that both the particle size of EPS microplastics and environmental parameters (temperature, salinity, and pH) play crucial roles in the release of HBCDs. The release rates of ΣHBCD (sum of α-, β- and γ-HBCD) from EPS microplastics in seawater ranged from 8.64 to 33.3 ng·g-1·d-1 under different conditions. Compared with the seawater control, a slight but not significant increase in the release of HBCDs was observed in the digestive fluids. The diastereoisomer profiles of HBCDs released from EPS microplastics both in seawater and digestive fluids were similar. The proportions of α-HBCD and β-HBCD released from EPS in seawater and digestive fluids were higher than those in the original EPS microplastics, especially for β-HBCD. The diffusion model explained the release data of HBCDs from EPS microplastics apparently better than the other two models, suggesting that the diffusion within the matrix of microplastic is a rate-limiting step. Based on the mass of EPS microplastics and release rates of HBCDs, the annual release of HBCDs from EPS microplastics into the global ocean was estimated to be 9.29 to 115 kg. These HBCDs would have profound impacts on marine organisms and even endanger human health and safety. Considering the abundance of microplastics in the ocean, the release of chemical additives from microplastics deserves more attention in the future.

Heavy metals that are adhered to the surfaces of microplastics in the natural marine environment pose potential threats to marine life. However, little is known about their adsorption mechanisms and composite risks. This study collected seawater, suspended particulate matter (SPM), plankton, and microplastic samples from the waters surrounding Hong Kong, established a method for analyzing 13 heavy metals in the plastisphere, and explored the extrinsic and intrinsic sources of the heavy metals by analyzing natural matrices (seawater, SPM, and plankton) and anthropogenic plastics. We found that heavy metals in the plastisphere were significantly affected by the surrounding matrices, as indicated by its positive correlations with the heavy metals in SPM and plankton at most of the sampling sites. Heavy metals in plankton usually occurred as traces of oxides such as As2O3 and ZnO. The partition coefficients of the studied heavy metals between seawater and the plastisphere were identical to those between the SPM and the plastisphere. No correlations were found between the concentrations of heavy metals in the plastisphere and the heavy metal concentrations, masses, quantities, or surface areas of the microplastics, although some polymer types contained extremely high Cd (676 mg/kg), Pb (1,742 mg/kg), and Zn (1,712 mg/kg) concentrations. Only the Cr, Cu, and Ni concentrations were positively correlated with the specific surface area of the microplastics. A cluster analysis showed that Cr, Cu, and Ni were derived from anthropogenic sources, indicating that adventive heavy metals could be adsorbed by plastics with large specific surface areas. We also established a new composite risk assessment method for heavy metals and microplastics that leverages the specific surface areas of microplastics. The assessment results showed that Cd from Tolo Harbor had a strong ecological risk, while As and Cd from the eastern waters off Hong Kong had moderate composite ecological risks.

The purpose of this study was to analyze nitrogen removal by anaerobic ammonium oxidation (anammox) process using sludge from Muara Penjalinan Padang as an inoculum in a filter bioreactor (FtBR). The configuration of FtBR consisted of a housing filter with an effective volume of 1,500 mL and a string wound filter cartridge of 0.5 µm as a carrier for the growth of anammox bacteria. The artificial wastewater was made using seawater containing ammonium and nitrite with a concentration of 70 mg-N/L, which was delivered to the reactor continuously with a hydraulic retention time (HRT) of 24 hours. Influent and effluent samples were collected once-twice a week to analyze the concentration of ammonium, nitrite, and nitrate, based on Nessler, spectrophotometry, and UV screening methods. Process anammox takes place in FtBR based on the average ratio of ?NO2--N/?NH4+-N and ?NO3--N / ?NH4+-N of 0.986 dan 0.239. The nitrogen removal performance was calculated based on the ammonium conversion efficiency (ACE), nitrogen removal efficiency (NRE), nitrogen loading rate (NLR), and nitrogen removal rate (NRR). After operating the reactor for 143 days, the nitrogen removal of ACE, NRE, and NRR were 20.268%, 16. 872%, and 0.026 kg-N/m3·d at NLR 0.1804 kg-N/m3·d. Keywords: Anammox, Filter bioreactor, Muara Penjalinan, Seawater, Sludge ABSTRAK Anaerobic ammonium oxidation (anammox) merupakan penyisihan amonium menjadi gas nitrogen menggunakan nitrit sebagai penerima elektron dan berkontribusi dalam penyisihan nitrogen di lautan. Penelitian ini bertujuan untuk menganalisis penyisihan nitrogen melalui proses anammox menggunakan lumpur Muara Penjalinan Kota Padang sebagai inokulum pada filter bioreactor (FtBR). Konfigurasi FtBR terdiri atas housing filter dan string wound filter cartridge sebagai media lekat untuk pertumbuhan biomassa anammox yang dioperasikan secara kontinu dengan hydraulic retention time (HRT) 24 jam pada suhu ambien. Limbah artifisial dibuat menggunakan air laut yang dengan menambahkan 70 mg-N/L amonium dan nitrit masing-masingnya yang dipompakan ke reaktor secara kontinu. Pengambilan sampel influen dan efluen dilakukan satu hingga dua kali dalam seminggu untuk pengukuran konsentrasi amonium, nitrit dan nitrat berdasarkan metode Nessler, spektrofotometri, dan skrining spektrofotometri ultraviolet. Proses anammox berlangsung dalam reaktor berdasarkan rasio ?NO2--N/?NH4+-N dan ?NO3--N / ?NH4+-N sebesar 0,986 dan 0,239 yang mendekati stoikiometri reaksi anammox. Setelah operasional reaktor selama 143 hari didapatkan kinerja penyisihan nitrogen maksimal ammonium conversion efficiency (ACE), nitrogen removal efficiency (NRE) dan nitrogen removal rate (NRR) berturut-turut 20,268%, 16,872% dan 0,026 kg-N/m3.h pada nitrogen loading rate (NLR) 0,1804 kg-N/m3.h. Kata kunci: Anammox, Filter bioreactor, Muara Penjalinan, Air laut, Lumpur

The present study investigated the effects of rising carbon dioxide levels in nature and the carbon sequestration potential of dominant mangrove species for reducing the toxic effects of ocean acidification. The study was conducted on the east coast of Odisha, in the western Bay of Bengal. To determine the effect of these ambient parameters on the absorption of carbon dioxide by the mangroves, water temperature, salinity, pH levels of seawater along with soil texture and pH, salinity expressed in electrical conductivity, compactness expressed in bulk density, and soil organic carbon were simultaneously monitored. The aboveground biomass and carbon of the selected species were studied for 2 consecutive years at 10 designated stations. The total carbon calculated for the study area varied from 242.50 ± 49.00 to 1321.29 ± 445.52 tons with a mean of 626.68 ± 174.81 tons for Bhitarkanika and Mahanadi mangrove chunks. This is equivalent to 2299.92 ± 641.55 tons of CO

Global climate changes, such as warming and ocean acidification (OA), are likely to negatively impact calcifying marine taxa. Abundant and ecologically important coralline algae may be particularly susceptible to OA; however, multi-stressor studies and those on articulated morphotypes are lacking. Here, we use field observations and laboratory experiments to elucidate the impacts of warming and acidification on growth, calcification, mineralogy, and photophysiology of the temperate articulated coralline alga, Calliarthron tuberculosum. We conducted a 4-week fully factorial mesocosm experiment exposing individuals from a southern CA kelp forest to current and future temperature and pH/pCO

Trace analyte detection in a complex environment such as in seawater is usually challenging for classic redox-based electrochemical sensors since the matrix effect of high salinity and various interfering species with similar redox properties can generate false positive/negative signals, thus impacting the sensitivity and specificity of the sensors. In this work, unlike redox-based approaches, we propose a novel sensing mode that relies on dual-modulated interfacial energy barriers of heterojunctions. By constructing the hierarchical structure of Ni/TiO

Little data on the persistence of human norovirus infectivity are available to predict its transmissibility. Using human intestinal enteroids, we demonstrate that 2 human norovirus strains can remain infectious for several weeks in seawater. Such experiments can improve understanding of factors associated with norovirus survival in coastal waters and shellfish.

To elucidate the seawater biological and physicochemical factors driving differences in organic composition between supermicron and submicron sea spray aerosol (SSA

Large-scale surveys represented by 5800 bathymetric casts in the western Indian Ocean (0-22

To investigate the occurrence and partition of total petroleum hydrocarbons (TPHs), sediment, seawater, and biota of the eastern sea area of Shandong Peninsula (China) were sampled in 2016. Due to shipping activities and discharge of industrial wastes, the TPH levels in the sediment decreased from the coastal areas to the offshore area. Waterborne TPH concentrations showed a decreasing order of autumn summer spring winter, probably caused by low input of pollutants from the river into the ocean in dry seasons and frequent aquaculture operations in wet seasons. The distribution coefficient (logK

The diversity of life on Earth is controlled by hierarchical processes that interact over wide ranges of timescales

International audience; The present study, conducted in the Galion Bay in Martinique, aims to highlight the temporal and seasonal variations of chlordecone contamination (an organochlorine pollutant) in the ambient environment (seawater) but also in the marine organisms in three main coastal marine habitats (mangroves, seagrass beds and coral reefs). To this end, two methodologies were used to measure and compare the chemical contamination of seawater during 13 months (spot samplings and POCIS technique). In parallel, concentrations of chlordecone and isotopic ratios (C and N) were carried out on marine organisms, collected during two contrasting climatic periods (dry and rainy), to evidence seasonal variations. The results showed that the contamination of seawater displayed significant variations over time and depended on environmental factors such as water flows, which imply dilution and dispersion phenomena. Concerning the marine organisms, the level of contamination varied considerably between the two seasons in seagrass beds with higher levels of contamination during the rainy season. Reef organisms were more moderately affected by this pollution, while mangrove organisms Environnemental Science and Pollution Research 2022 2 showed a high level of chlordecone whatever the season. Finally, isotope analyses highlighted that bioamplification along marine food-webs occurs at each season and each station.

Environmental virus communities are highly diverse. However, the infection physiology underlying the evolution of diverse phage lineages and their ecological consequences are largely unknown. T7-like cyanophages are abundant in nature and infect the marine unicellular cyanobacteria, Synechococcus and Prochlorococcus, important primary producers in the oceans. Viruses belonging to this genus are divided into two distinct phylogenetic clades: clade A and clade B. These viruses have narrow host-ranges with clade A phages primarily infecting Synechococcus genotypes, while clade B phages are more diverse and can infect either Synechococcus or Prochlorococcus genotypes. Here we investigated infection properties (life history traits) and environmental abundances of these two clades of T7-like cyanophages. We show that clade A cyanophages have more rapid infection dynamics, larger burst sizes and greater virulence than clade B cyanophages. However, clade B cyanophages were at least 10-fold more abundant in all seasons, and infected more cyanobacteria, than clade A cyanophages in the Red Sea. Models predicted that steady-state cyanophage abundances, infection frequency, and virus-induced mortality, peak at intermediate virulence values. Our findings indicate that differences in infection properties are reflected in virus phylogeny at the clade level. They further indicate that infection properties, together with differences in subclade diversity and host repertoire, have important ecological consequences with the less aggressive, more diverse virus clade having greater ecological impacts.

Ocean acidification is impacting marine life all over the world. Understanding how species can cope with the changes in seawater carbonate chemistry represents a challenging issue. We addressed this topic using underwater CO2 vents that naturally acidify some marine areas off the island of Ischia. In the most acidified area of the vents, having a mean pH value of 6.7, comparable to far-future predicted acidification scenarios (by 2300), the biomass is dominated by the brown alga Sargassum vulgare. The novelty of the present study is the characterization of the S. vulgare proteome together with metabolite analyses to identify the key proteins, metabolites, and pathways affected by ocean acidification. A total of 367 and 387 proteins were identified in populations grown at pH that approximates the current global average (8.1) and acidified sites, respectively. Analysis of their relative abundance revealed that 304 proteins are present in samples from both sites: 111 proteins are either higher or exclusively present under acidified conditions, whereas 120 proteins are either lower or present only under control conditions. Functionally, under acidification, a decrease in proteins related to translation and post-translational processes and an increase of proteins involved in photosynthesis, glycolysis, oxidation-reduction processes, and protein folding were observed. In addition, small-molecule metabolism was affected, leading to a decrease of some fatty acids and antioxidant compounds under acidification. Overall, the results obtained by proteins and metabolites analyses, integrated with previous transcriptomic, physiological, and biochemical studies, allowed us to delineate the molecular strategies adopted by S. vulgare to grow in future acidified environments, including an increase of proteins involved in energetic metabolism, oxidation-reduction processes, and protein folding at the expense of proteins involved in translation and post-translational processes.

Anthropogenic stressors are predicted to alter biodiversity and ecosystem functioning worldwide. However, scaling up from species to ecosystem responses poses a challenge, as species and functional groups can exhibit different capacities to adapt, acclimate, and compensate under changing environments. We used a naturally acidified seagrass ecosystem (the endemic Mediterranean Posidonia oceanica) as a model system to examine how ocean acidification (OA) modifies the community structure and functioning of plant detritivores, which play vital roles in the coastal nutrient cycling and food web dynamics. In seagrass beds associated with volcanic CO

Molecular methodologies providing data on viral concentration and infectivity have been successfully used in environmental virology, supporting quantitative risk assessment studies. The present study aimed to assess human mastadenovirus (HAdV) intact particles using a derivative of propidium monoazide associated with qPCR (PMAxx-qPCR) in aquatic matrices. Initially, different concentrations of PMAxx were evaluated to establish an optimal protocol for treating different naturally contaminated matrices, using 10 min incubation in the dark at 200 rpm at room temperature and 15 min of photoactivation in the PMA-Lite™ LED photolysis device. There was no significant reduction in the quantification of infectious HAdV with increasing concentration of PMAxx used (20 μM, 50 μM, and 100 μM), except for sewage samples. In this matrix, a reduction of 5.01 log of genomic copies (GC)/L was observed from the concentration of 50 μM and revealed 100% HAdV particles with damaged capsids. On the other hand, the mean reduction of 0.51 log in stool samples using the same concentration mentioned above demonstrated 83% of damaged particles eliminated in the stool. Following, 50 μM PMAxx-qPCR protocol revealed a log reduction of 0.91, 0.67, and 1.05 in other samples of raw sewage, brackish, and seawater where HAdV concentration reached 1.47 × 10

Environmental DNA (eDNA) quantification and sequencing are emerging techniques for assessing biodiversity in marine ecosystems. Environmental DNA can be transported by ocean currents and may remain at detectable concentrations far from its source depending on how long it persist. Thus, predicting the persistence time of eDNA is crucial to defining the spatial context of the information derived from it. To investigate the physicochemical controls of eDNA persistence, we performed degradation experiments at temperature, pH, and oxygen conditions relevant to the open ocean and the deep sea. The eDNA degradation process was best explained by a model with two phases with different decay rate constants. During the initial phase, eDNA degraded rapidly, and the rate was independent of physicochemical factors. During the second phase, eDNA degraded slowly, and the rate was strongly controlled by temperature, weakly controlled by pH, and not controlled by dissolved oxygen concentration. We demonstrate that marine eDNA can persist at quantifiable concentrations for over 2 weeks at low temperatures (≤10 °C) but for a week or less at ≥20 °C. The relationship between temperature and eDNA persistence is independent of the source species. We propose a general temperature-dependent model to predict the maximum persistence time of eDNA detectable through single-species eDNA quantification methods.

A series of experiments and simulations were performed to ascertain the rate at which phosphorus is released using a water quality model in Saemangeum Lake, an artificially constructed lake located in an estuary. The general inflow of seawater once a day contributed to the formation of a halocline in the lake water, which caused variation in the vertical concentration of dissolved oxygen. The halocline was mainly observed in the deep downstream regions of Saemangeum Lake that are close to the open sea. In contrast, the shallower regions upstream, which are under the influence of pollutant-loading from upstream rivers, exhibited high concentrations of chemical oxygen demand, total phosphorus, and Chl-a, resulting in lower water quality than the downstream regions. Laboratory experiments investigating the release of phosphorus at five representative locations showed that the upstream release flux, where the halocline was weaker, was higher than that downstream, where the initial level of phosphorus sedimentation was high. In particular, a need for an accurate evaluation method for the release of phosphorus at each site was suggested as slight differences were obtained depending on the estimation method used at each representative location. The results of the phosphorus release experiments led to the use of time-weighted integration (TWI), terminated time evaluation, and statistical mean value; the Environmental Fluid Dynamics Code–National Institute of Environment Research model, a widely used water quality model for studying retention watersheds, was applied to the simulation of hydraulic and water quality characteristics for the Saemangeum Lake and its surrounding waters. The result of the water quality simulation indicated the highest reproducibility for release-time TWI so that TWI values were more useful in predicting phosphorus concentrations and the subsequent management of water quality.

Marine biofouling occurs through the colonization of undesired microorganisms on the surfaces of structures. In this study, four immersion cycles (2, 5, 15, and 25 days) of total immersion in seawater were carried out at the Sanya Marine Environmental Test Station using three materials: industrial pure titanium (Ti), hot-dip zinc (Zn), and glass slide (GS). Three phyla, four classes, and nine bacterial genera were identified. The dominant genera were Pseudomonas, Alteromonas, and Pseudoalteromonas. The number of bacteria increased with soaking time. Sixty-one species of diatoms belonging to 30 genera, 24 families, and 16 orders were detected, among which the dominant genera were Amphora, Nitzschia, and Navicula. Four genera of ciliates belonged to two classes, three orders, and four families, among which the dominant species were Euplotes sp. and Uronema marinum. Tubular polychaetes was the dominant metazoans. Species diversity increased over time. The highest biofilm diversity was observed on the GS surface. The diversity of biofilms on the Ti surface was higher than that on the Zn surface. This study provides basic data for marine material research, marine corrosion, and national defence construction.

Bilayer solar evaporator combines high photothermal conversion capacity and low heat loss, has become the new darling in interfacial solar steam generation (ISSG). However, the bilayer structure generally achieved by introducing a photothermal coating on the substrate is not conducive to long-term use due to the poor stability of coating. Herein, a fully biomass-based bilayer evaporator is all-in-one designed, using chitosan (CS) as building blocks and CS derived N, S - doped porous carbon (NSPC) as fillers via pre-freezing and freeze-drying. This facile method could realise the quantitative addition of photothermal materials and controllably regulate the structure of the bilayer evaporator, making the structural optimisation readily available. The optimised evaporator exhibits a remarkable evaporation rate of 2.51 kg m

Two-dimensional (2D) material-based membranes are promising candidates for various separation applications. However, the further enhancement of membrane ion conductance is difficult, and the regulation of membrane ion selectivity remains a challenge. Here, we demonstrate the facile fabrication of MXene composite membranes by incorporating spacing agents that contain SO

Diatoms account for up to 40% of marine primary production1,2 and require silicic acid to grow and build their opal shell3. On the physiological and ecological level, diatoms are thought to be resistant to, or even benefit from, ocean acidification4–6. Yet, global-scale responses and implications for biogeochemical cycles in the future ocean remain largely unknown. Here we conducted five in situ mesocosm experiments with natural plankton communities in different biomes and find that ocean acidification increases the elemental ratio of silicon (Si) to nitrogen (N) of sinking biogenic matter by 17 ± 6 per cent under $${{p}}_{{{\rm{CO}}}_{2}}$$ p CO 2 conditions projected for the year 2100. This shift in Si:N seems to be caused by slower chemical dissolution of silica at decreasing seawater pH. We test this finding with global sediment trap data, which confirm a widespread influence of pH on Si:N in the oceanic water column. Earth system model simulations show that a future pH-driven decrease in silica dissolution of sinking material reduces the availability of silicic acid in the surface ocean, triggering a global decline of diatoms by 13–26 per cent due to ocean acidification by the year 2200. This outcome contrasts sharply with the conclusions of previous experimental studies, thereby illustrating how our current understanding of biological impacts of ocean change can be considerably altered at the global scale through unexpected feedback mechanisms in the Earth system.

We assessed the contamination, dynamics, and health risks of the pesticides cyanazine, simetryn, fenarimol, isoprothiolane, diazinon, irgarol, fenitrothion, and diuron in marine samples (seawater, sediments, plankton, fish, and other edible organisms) at various locations in the Seto Inland Sea in Japan in 2016 and 2017. Pesticide concentrations were highest at sampling sites close to the coastline, and mean concentrations in seawater were slightly higher in surface water than in bottom water. All eight pesticides were detected in plankton. Diazinon concentrations (77-387 ng/g dw) were highest in sediments and cyanazine was the most frequently detected pesticide (88%, n = 17) in sediments. Only cyanazine (2.7-41.9 ng/g dw), simetryn (1.0-34.3 ng/g dw), and diazinon (6.3-308.8 ng/g dw) were detected in fish and other edible marine organisms. Based on the calculated bioconcentration factor, the results showed that plankton, fish, and marine animals bioaccumulated pesticides. The highest hazard quotients were calculated for diazinon in red seabream and greenling, indicating a possible risk to consumers. It is, therefore, imperative to promote strict implementation of pollution control, integrated pest management practices, and policy formulation on pesticides. Usage of diazinon must be controlled and monitored to ensure large residues do not reach aquatic ecosystems and marine coastlines.