Spatial distribution and seasonal variation of trace hazardous elements contamination in the coastal environment

Groundwater is the second largest water source for daily consumption, only next to surface water resources. Groundwater has been extensively investigated for its pollution level in urban areas. The groundwater quality assessments in industrial areas associated with every urban landscape are still lacking. In order to examine the spatial distribution characteristics, pollution levels, and sources of trace metals in the densely populated Chennai coastal region of Tamilnadu, India, physicochemical parameters and trace element concentrations have been determined in groundwater. 55 groundwater samples from Tamil Nadu's coastal region were collected and analyzed for physicochemical parameters such as pH, (EC), (TDS), and (TH) during the pre-monsoon (June 2015) and post-monsoon (January 2016) seasons. We used trace elements and analyzed them in this study (Mg, Zn, Pb, Ni, Co, Cu, Cr, and Fe). Furthermore, anthropogenic input from industries and power plants exacerbates the pollution of Ni, Mg, Fe, and Mn. Due to evaporites and anthropogenic input, samples with excessive salinity, total hardness, and water quality are considered unsuitable for irrigation or drinking. The results demonstrated that seasonal, geogenic, and anthropogenic influences all have a significant impact on the heterogeneous chemistry of groundwater.

Vanishing lead in the Loire River estuary: An example of successful environmental regulation

The behavior, and history of lead (Pb) contamination in the ecosystem of the Loire estuary was examined using elemental concentrations and Pb isotope data in water, sediment, bivalves, shrimps, and fish. In the estuary and in the surrounding coastal area, Pb concentrations in water and sediment decreased compared to concentrations determined in the 1980s, with concentrations ranging from 15.8 to 65.7 mg kg-1 in the surface sediment, 0.04-0.26 nM in the water column, and 48.0-77.9 mg kg-1 in suspended particles. Pb biomonitoring using blue mussels collected by the French Mussel Watch Program over the last 40 years showed a concentration decrease from 3.8 to 0.8 mg kg-1. A similar trend is observed in an estuarine sediment core. Changes in accompanying Pb isotope compositions strongly suggest a binary mixing process between Pb derived from terrigenous material and anthropogenic sources. Thus, environmental regulations restricting the release of lead into the environment contribute to a decrease in estuarine levels of this pollutant, which occurs on a decadal time scale.

The molecular level degradation state of drift plastics in the Sea of Japan coastline

Polyethylene (PE) and polyethylene terephthalate (PET) are among the most abundant plastics polluting the oceans. However, their environmental fate depends on how they have been weathered. Due to its unique geography, the Sea of Japan is a pollution hotspot where plastics accumulate. In this study, the structures of plastics, having drifted into the Sea of Japan coastline environment, were analyzed with a particular focus on examining polymer crystallization and carbonyl formation; two factors which influence microplastic formation and the adsorption of contaminants onto plastic surfaces. PE in the coastal environment did not show evidence of crystallization, although carbonyl formation did increase. By contrast, PET bottles were shown to not be uniform in structure, with unaged bottles being less crystalline in the neck component compared to the body. Because of this difference, in environmental PET bottles, it was the bottle neck that showed increases in crystallization and carbonyl group formation.

Effects of TiO2 ultraviolet filter and sunscreens on coastal dune plant performance and competitive interactions

Ultraviolet filters (UVFs) added to sunscreens (SS) are emerging contaminants in marine environments due to their adverse effects on organisms and ecosystems. UVFs have also been detected in beach-dune systems, but their influence on resident organisms has not been explored yet. Native plants are fundamental components of coastal dunes, and these ecologically/economically important systems are currently among the most threatened globally. Thus, understanding whether UVFs may act as threats to dune plants is crucial. This field study evaluated and compared the effects of titanium dioxide nanoparticles (nTiO2), one of the inorganic UVFs most commonly added to sunscreens, and those of a commercial sunscreen product containing it (SS-nTiO2) on the performance of adult dune plants of a native (Thinopyrum junceum) and a non-native invasive species (Carpobrotus sp. pl.) and their competitive interactions at environmentally realistic concentrations. The effects of nTiO2, SS-nTiO2 and of a sunscreen product containing just organic UVFs (SS-OF) on early life stages of T. junceum were also examined. Ti bulk content in sand and plants at the study site ranged from 970 to 1069 mg kg-1 and from 2 to 7.9 mg kg-1, respectively. Thinopyrum junceum adult plants periodically exposed during the summer season to seawater contaminated by SS-nTiO2 produced less biomass than un-exposed plants and nTiO2 exposed plants. nTiO2 and SS-nTiO2 reduced the capacity of T. junceum to control the spread of Carpobrotus. Both SS-nTiO2 and SS-OF reduced seedling emergence in T. junceum whereas nTiO2 did not. These results demonstrated that the periodical exposures of native dune plants to sunscreens could reduce their establishment success and growth and favor invasive plant spread potentially resulting in community structure changes. They also emphasize the need to assess the phytotoxicity not only of single UVFs but especially that of complete sunscreen products to design more eco-friendly formulations in the future.

Intra-annual variation in microplastics in mussels (Mytilus galloprovincialis) inhabiting an urbanized bay of South Korea

This study investigated the presence of microplastics (MPs) in mussels from an urbanized bay in Korea, focusing on intra-annual variation. The average MP concentration was 0.36 ± 0.14 n/g w.w. (1.24 ± 0.56 n/individual). MPs were detected throughout the year with minor monthly variation and no significant monthly changes. Although there was no correlation between MP concentration in mussel and seawater, a positive relationship was observed when normalizing MPs to mussel's condition index (except for July). Polypropylene, polyethylene and acrylate polymer were dominant MPs, with high-density polymers comprising 59 % of the total. Most MPs were fragments and particles <200 μm. This study indicates that strict time restrictions for mussel sampling may not be necessary to assess MP levels in this bay. Additionally, considering MPs in seawater, biological conditions of mussel may be essential for understanding variations in MP levels in mussels. Including small MPs (<200 μm) and high-density polymers in MP assessment is recommended.

Plastic litter changes the rhizosphere bacterial community of coastal dune plants

The presence of plastic litter in coastal environments like beach-dune systems has been well documented, and recent studies have shown that this pollutant can influence sand properties as well as dune vegetation. However, the effects of plastics on rhizosphere bacterial communities of dune plants have largely been neglected. This is an ecologically relevant issue since these communities may play an important role in improving plant growth and resilience of dune systems. Here, we explored the impact of plastic litter made of either non-biodegradable polymers (NBP) or biodegradable/compostable polymers (BP) on the structure and composition of rhizosphere bacterial communities associated with two widespread species along coastal European dunes, Thinopyrum junceum and Sporobolus pumilus, by using a one-year field experiment combined with metabarcoding techniques. Both plastics did not affect neither the survival nor the biomass of T. junceum plants, but they significantly increased alpha-diversity of rhizosphere bacterial communities. They also changed rhizosphere composition by increasing the abundance of the phyla Acidobacteria, Chlamydiae, and Nitrospirae, and of the family Pirellulaceae, and reducing the abundance of the family Rhizobiaceae. NBP reduced drastically the survival of S. pumilus while BP increased its root biomass compared to controls. BP also increased the abundance of the phylum Patescibacteria of the rhizosphere bacterial communities. Our findings provide the first evidence that NBP and BP can change rhizosphere bacterial communities associated with dune plants and highlight the importance of investigating how these changes can affect the resilience of coastal dunes to climate change.

The joint effects of atmospheric dry and wet deposition on organic carbon cycling in a mariculture area in North China

In this research, the atmospheric dry and wet deposition fluxes of particulate organic carbon (POC) over the coastal waters around the Yangma Island in North Yellow Sea were investigated. Combining the results of this research and previous reports about the wet deposition fluxes of dissolved organic carbon (DOC) in precipitation (F_DOC-wet) and dry deposition fluxes of water-dissolvable organic carbon in atmospheric total suspended particles (F_DOC-dry) in this area, a synthetic assessment of the influence of atmospheric deposition on the eco-environment was conducted. It was found that the annual dry deposition flux of POC was 1097.9 mg C m^-2 a^-1, which was approximately 4.1 times that of F_DOC-dry (266.2 mg C m^-2 a^-1). For wet deposition, the annual flux of POC was 445.4 mg C m^-2 a^-1, accounting for 46.7 % that of F_DOC-wet (954.3 mg C m^-2 a^-1). Therefore, atmospheric POC was mainly deposited through dry process with the contribution of 71.1 %, which was contrary to the deposition of DOC. Considering the indirect input of organic carbon (OC) from atmospheric deposition, that is, the new productivity supported by nutrient input from dry and wet deposition, the total OC input from atmospheric deposition to the study area could be up to 12.0 g C m^-2 a^-1, highlighting the important role of atmospheric deposition in the carbon cycling of coastal ecosystems. The contribution of direct and indirect input of OC through atmospheric deposition to the dissolved oxygen consumption in total seawater column was assessed to be lower than 5.2 % in summer, suggesting a relatively smaller contribution to the deoxygenation in summer in this region.

Seafloor warm water temperature anomalies impact benthic macrofauna communities of a high-Arctic cold-water fjord

Amid the alarming atmospheric and oceanic warming rates taking place in the Arctic, western fjords around the Svalbard archipelago are experiencing an increased frequency of warm water intrusions in recent decades, causing ecological shifts in their ecosystems. However, hardly anything is known about their potential impacts on the until recently considered stable and colder northern fjords. We analyzed macrobenthic fauna from four locations in Rijpfjorden (a high-Arctic fjord in the north of Svalbard) along its axis, sampled intermittently in the years 2003, 2007, 2010, 2013 and 2017. After a strong seafloor warm water temperature anomaly (SfWWTA) in 2006, the abundance of individuals and species richness dropped significantly across the entire fjord in 2007, together with diversity declines at the outer parts (reflected in Shannon index drops) and increases in beta diversity between inner and outer parts of the fjord. After a period of three years with stable water temperatures and higher sea-ice cover, communities recovered through recolonization processes by 2010, leading to homogenization in community composition across the fjord and less beta diversity. For the last two periods (2010-2013 and 2013-2017), beta diversity between the inner and outer parts gradually increased again, and both the inner and outer sites started to re-assemble in different directions. A few taxa began to dominate the fjord from 2010 onwards at the outer parts, translating into evenness and diversity drops. The inner basin, however, although experiencing strong shifts in abundances, was partially protected by a fjordic sill from impacts of these temperature anomalies and remained comparatively more stable regarding community diversity after the disturbance event. Our results indicate that although shifts in abundances were behind important spatio-temporal community fluctuations, beta diversity variations were also driven by the occurrence-based macrofauna data, suggesting an important role of rare taxa. This is the first multidecadal time series of soft-bottom macrobenthic communities for a high-Arctic fjord, indicating that potential periodic marine heatwaves might drive shifts in community structure, either through direct effects from thermal stress on the communities or through changes in environmental regimes led by temperature fluctuations (i.e. sea ice cover and glacial runoff, which could lead to shifts in primary production and food supply to the benthos). Although high-Arctic macrobenthic communities might be resilient to some extent, sustained warm water anomalies could lead to permanent changes in cold-water fjordic benthic systems.

Investigation and comparative analysis of ecological risk for heavy metals in sediment and surface water in east coast estuaries of India

The sediments and surface water from 8 stations each from Dhamara and Paradeep estuarine areas were sampled for investigation of heavy metals, Cd, Cu, Pb, Mn, Ni, Zn, Fe, and Cr contamination. The objective of the sediment and surface water characterization is to find the existing spatial and temporal intercorrelation. The sediment accumulation index (I_sed), enrichment index (I_En), ecological risk index (I_EcR) and probability heavy metals (p-HMI) reveal the contamination status with Mn, Ni, Zn, Cr, and Cu showing permissible (0 ≤ I_sed ≤ 1, I_En ˂ 2, I_EcR ≤ 150) to moderate (1 ≤ I_sed ≤ 2, 40 ≤ R_f ≤ 80) contamination. The p-HMI reflects the range from excellent (p-HMI = 14.89-14.54) to fair (p-HMI = 22.31-26.56) in off shore stations of the estuary. The spatial patterns of the heavy metals load index (I_HMc) along the coast lines indicate that the pollution hotspots are progressively divulged to trace metals pollution over time. Heavy metal source analysis coupled with correlation analysis and principal component analysis (PCA) was used as a data reduction technique, which reveals that the heavy metal pollution in marine coastline might originate from redox reactions (FeMn coupling) and anthropogenic sources.

Abundance and characterization of microplastics in amphipods from the Japanese coastal environment

Microplastics can be ingested by tiny detritivores such as amphipods, with potential consequences on the food chain. The present study characterizes the abundance, chemical composition, and size of microplastics in amphipods found in the Japan Sea coastal environment, which is a hotspot for microplastic accumulation. High amounts of microplastic ingestion and a large discrepancy by amphipod species, Talorchestia nipponensis, Ampithoe valida, and Trinorchestia trinitatis, were observed (between 0.2 and 76.3 particles/individual) which may be due to differences in habitat preference and background contamination. This result indicates that coastal amphipods in particular may ingest large amounts of microplastics. The average microplastic particle size in amphipods was 59 ± 8.6 µm, with 83% of particles smaller than 90 µm, and polyethylene was dominant. This study provides insights into microplastic abundance in coastal amphipods and the context for further studies on coastal amphipod microplastic ingestion.

Pollution and ecological risk assessments for heavy metals in coastal, river, and road-deposited sediments from Apia City in Upolu Island, Samoa

This study was the first to investigate the pollution and ecological risks of heavy metals in coastal, river/stream and road-deposited sediments (RDS) from Apia in Samoa. Cr and Ni concentrations in sediment samples were higher than those of other metals. River sediments and RDS had relatively high EF values around the intensive commercial areas, with a moderate to significant enrichment of Cu, Zn, Cd, and Pb. The results indicate that Cr and Ni have a natural origin from volcanic parent materials, while Cu, Zn, Cd, and Pb originated from anthropogenic activities, such as traffic emissions and the discharge of municipal wastewater. The assessments of pollution and ecological risk revealed that coastal sediments adjacent to the river are anthropogenically contaminated and present a moderate ecological risk. This study demonstrates that metals that have accumulated in the urban impermeable layer and river/stream bed have flowed into the coastal environment through runoff.

Environmental magnetic signatures in mangrove ecosystems in northern Persian Gulf: Implication for pollution assessment in marine environment

Magnetic properties of root, bark, and leaf of mangrove (Avicenna marina) and sediment were determined for pollution assessment at three locations in the northern coast of the Persian Gulf. The study revealed that the sources of the particles deposited on leaf surfaces can be discriminated via saturation isothermal remanent magnetization (SIRM) values and heavy metal. However, different factors including wind direction, size of the magnetic particles and crown density, play a role using SIRM for biomonitoring of atmospheric particulate matter. For leaves, the significant correlations between SIRM and leaf elemental contents indicated that the deposited particles on their surface mainly have geogenic sources. The magnetic analyses revealed that leaves are more suitable than bark for monitoring atmospheric pollution using mangrove trees due to the effect of different factors including dense crown of trees, washing of tree trunk by sea waves, and elements translocation from roots and sediments. Instead, the positive and significant correlation between the SIRM values for sediments and mangrove roots, and no or negative correlation between sediments and roots with barks and leaves indicates that the magnetic properties of the sediments and mangrove roots are suitable indicators of pollution in aquatic environment.

Composition and functionality of bacterioplankton communities in marine coastal zones adjacent to finfish aquaculture

Finfish aquaculture is a fast-growing primary industry and is increasingly common in coastal ecosystems. Bacterioplankton is ubiquitous in marine environment and respond rapidly to environmental changes. Changes in bacterioplankton community are not well understood in semi-enclosed stratified embayments. This study aims to examine aquaculture effects in the composition and functional profiles of the bacterioplankton community using amplicon sequencing along a distance gradient from two finfish leases in a marine embayment. Results revealed natural stratification in bacterioplankton associated to NOx, conductivity, salinity, temperature and PO₄. Among the differentially abundant bacteria in leases, we found members associated with nutrient enrichment and aquaculture activities. Abundant predicted functions near leases were assigned to organic matter degradation, fermentation, and antibiotic resistance. This study provides a first effort to describe changes in the bacterioplankton community composition and function due to finfish aquaculture in a semi-enclosed and highly stratified embayment with a significant freshwater input.

The role of alcohol and drug intoxication in fatal drowning and other deaths that occur on the Australian coast

INTRODUCTION

Alcohol and drug (illicit or prescription) intoxication impairs motor skills, coordination, decision making abilities, hazard perception, and is known to increase the risk of death in coastal environments. Prior coastal safety research has focused largely on the impact of alcohol on drowning, with less research on the influence of drugs and leaving a significant number of other non-drowning fatalities largely excluded, despite being preventable with mitigation of injuries or medical factors.

METHOD

This retrospective cross-sectional study explored the impact of alcohol and drugs on unintentional Australian drowning deaths and other coastal fatalities over a 16-year period to identify higher-risk populations and coastal activity groups for which alcohol/drug use is increased.

RESULTS

It was found that alcohol, benzodiazepines/sedatives, and amphetamine usage was prevalent in coastal deaths. Of the 2,884 coastal deaths, 80.6% of decedents had known toxicological data. Alcohol and/or drug intoxication contributed to 23% of coastal drowning deaths and 19% of fatalities. For drowning and other fatalities combined, 8.7% were due to alcohol, 8.7% due to drugs, and 4.1% due to both alcohol and drugs. Australian-born decedents were more likely to involve alcohol (RR = 1.7, 95%CI = 1.26-2.3, p &lt; 0.001), drugs (RR = 2.62, 95%CI = 1.85-3.7, p &lt; 0.001), or both alcohol and drugs (RR = 4.43, 95%CI = 2.51-7.82, p &lt; 0.001) with an increased risk identified in Indigenous Australian populations (RR = 2.17, 95%CI = 1.12-4.24, p = 0.04). The impact of alcohol and drug intoxication varied by activity, with Personal Watercraft users more likely to die due to alcohol intoxication (RR = 2.67, 95%CI = 1.23-5.78, p = 0.035), while scuba divers (RR = 0, p &lt; 0.001), snorkelers (RR = 0.14, 95%CI = 0.036-0.57, p &lt; 0.001), and rock fishers (RR = 0.46, 95%CI = 0.22-0.96, p = 0.03) were less likely. Recreational jumping and fall-related coastal deaths were more likely to involve alcohol and alcohol/drugs combined.

PRACTICAL APPLICATIONS

This study identifies factors to further investigate or target with prevention strategies to decrease the holistic burden of mortality due to alcohol and/or drug usage on the Australian coast.

Elucidating sources of atmospheric NOX pollution in a heavily urbanized environment using multiple stable isotopes

Atmospheric deposition of nitrogen (N) from rain and aerosols can be a significant non-point source - particularly in urbanized coastal areas and contribute to coastal eutrophication and hypoxia. Here, we present geochemical and isotopic data from surface waters coupled with an 18-month time series of geochemical and isotopic data measured on wet and dry deposition over Hong Kong from June 2018. Dual stable isotopes of nitrate (δ¹⁵N-NO₃^- and δ¹⁸O-NO₃^-) of rain and total suspended particulates (TSP) were analyzed to trace the sources and understand seasonal pattern of atmospheric nitrate. The δ¹⁵N of TSP, δ¹⁵N-NO₃ in rain and TSP ranged from +0.94 to +17.6‰, -4.1 to +3.0‰ and -1.3 to +9.0‰ respectively. δ¹⁵N varied seasonally with higher values in winter and lower values in summer. This variation can be explained by a change in the sources of atmospheric NO_x driven by the East Asian Monsoon. It was found that most NO_x comes from coal burning in winter and a mix of vehicle emissions, fossil fuel combustion and lightning in summer. Moreover, the estimated dry and wet deposition of nitrate and ammonium in Hong Kong is around 18 kg N ha^-1 annually, which is of the same order of magnitude as N released by sewage effluents and groundwater. This implies that atmospheric N deposition over the N-limited waters of the eastern side of Hong Kong could contribute significantly to the N budget. Therefore, atmospheric N deposition may alter the local N marine cycling, thus monitoring its impact is crucial for water quality in Southern China.

Sources, behaviors, transformations, and environmental risks of organophosphate esters in the coastal environment: A review

The rapid growth in the global production of organophosphate esters (OPEs) has resulted in their high environmental concentrations. The low removal rate of OPEs makes the effluents of wastewater treatment plants be one of the major sources of OPEs. Due to relatively high solubility and mobility, OPEs can be carried to the coastal environment through river discharge and atmospheric deposition. Therefore, the coastal environment can be an important OPE sink. Previous studies have shown that OPEs were widely detected in coastal atmospheres, water, sediments, and even aquatic organisms. OPEs can undergo various environmental processes in the coastal environment, including adsorption/desorption, air-water exchange, and degradation. In addition, bioaccumulation of OPEs was observed in coastal biota but current concentrations would not cause significant ecological risks. More efforts are required to understand the environmental behaviors of OPEs and address resultant environmental and health risks, especially in the complicated environment.

Impact of storms and proximity to entry points on marine litter and wrack accumulation along Mediterranean beaches: Management implications

Beach litter can affect public health and economic activities worldwide forcing local authorities to expensive beach cleaning. Understanding the key mechanisms affecting the accumulation of this waste on beaches, such as sea state and proximity to entry points, is critical to plan effective management strategies. In this one-year study, we estimated the impact of storm events and waterways runoff on litter abundance and local economy using as a model a managed, peri-urban beach facing a north-western sector of the Mediterranean Sea. We also investigated the relationship between litter composition/density and beach proximity to major/closest harbors/rivers at regional scale by combining our data with those on litter density available in literature. Autumn/winter storms caused larger litter depositions than spring/summer ones in the peri-urban beach. No preferential accumulation occurred near to waterway mouths. Litter mainly consisted of plastic, and its composition in terms of micro-categories varied over seasons. In total, 367,070 items were deposited along 4.7 km of beach over one year, and the cost for the removal of this waste amounted to approximately 27,600 euros per km/year. At regional scale, beach litter density was positively correlated to the proximity of major harbors while its composition was related to the proximity to both major harbors and rivers. Results indicate that autumn/winter storms are important drivers of marine litter deposition. They also suggest that beaches in front of the convergence zone of littoral currents and close to major harbors can be particularly subjected to this kind of pollutant. To increase their effectiveness, litter mitigation/cleaning activities should be planned based on predictions of major storm events and performed at spatial scales encompassing at least coastal regional sectors.

Occurrence of polychlorinated biphenyls (PCBs) in the sea anemone Bunodosoma zamponii, sediments and seawater from the southwestern Atlantic

Polychlorinated biphenyls (PCBs) are persistent and bioaccumulable organic compounds. The occurrence of PCBs was assessed in two populations of the intertidal sea anemone Bunodosoma zamponii living under different anthropogenic strains. One location was in vicinity to a wastewater plant (Las Delicias, LD), and the other was a preserved location chosen as a reference site (Punta Cantera, PC). Anemone populations were sampled 4 times (spring, summer, autumn and winter) throughout a year, in addition to seawater and sediment from those areas. PCB loadings ranged from 2.89 to 79.41 ng L^-1 in seawater samples and from 0.07 to 6.61 ng g^-1 dry weight in sediment samples. Total PCB levels ranged from 0.22 to 14.94 and 2.79 to 24.69 ng g^-1 wet weight in anemones from PC and LD, respectively. PCBs concentrations in anemones from LD were significantly greater than PC during spring, summer and winter. The congeners 18 and 44 prevailed in seawater samples, 44 and 52 in sediment and 18 and 132+153 in anemones. Redundancy analysis integrated PCB levels from all matrixes and bolstered contrast between sampling sites. Seasonality was also a relevant factor since during winter PCB loading was greater in sediment and anemone samples, coincident with the rainiest season. Disparity between sites could be due to LD's proximity to the wastewater plant, effect of littoral drift direction and/or asymmetries in anemones physiological condition.

The impacts of intensive scallop farming on dissolved organic matter in the coastal waters adjacent to the Yangma Island, North Yellow Sea

In-situ field investigations coupled with incubation experiments were conducted in the coastal waters adjacent to the Yangma Island to explore the impacts of intensive bay scallop farming on the quantity and composition of dissolved organic matter (DOM). During the scallop farming period, the values of dissolved organic carbon (DOC), chromophoric dissolved organic matter (CDOM) and fluorescence dissolved organic matter (FDOM) in the mariculture area (MA) were generally higher than those in the non-mariculture area (NMA). Bay scallops released a large amount of DOM with the characteristics of high molecular weight and low degree of humification into the water column through excretion, which altered the DOM biogeochemical cycle. The DOM excretion fluxes by scallop were calculated based on incubation experiments. The results showed that, without considering the DOM transformation in the water, the excretion process of bay scallops in a growth cycle can increase the concentration of DOC, CDOM and fluorescent components C1-C4 in the seawater in MA by 19.7 μmol l^-1, 0.048 m^-1, 0.065 QSU, 0.164 QSU, 0.017 QSU and 0.015 QSU, respectively. Assuming that the labile part of DOM excreted by scallops was completely aerobic decomposed, it could reduce DO and pH in the seawater by ~13.4 μmol l^-1 and ~ 0.018 in MA. This study highlights the impact of human activities (scallop farming activities) on DOM cycle in coastal waters, which can help guide future policy formulating of mariculture and ecological protection.

Insights into the distribution, partitioning and influencing factors of antibiotics concentration and ecological risk in typical bays of the East China Sea

In order to obtain in-depth insight of the behavioral fate and ecological risks of antibiotics in coastal environment, this study investigated the distribution, partitioning and primary influencing factors of antibiotics in water and sediment in the East China Sea. After quantification of 77 target antibiotics in 6 categories, ten antibiotics were detected simultaneously with a detection frequency >50.0% in water and sediment; the concentrations of these ten antibiotics were 0.1-1508.0 ng L^-1 and 0.01-9.4 ng g^-1 in water and dry sediment, respectively. Sulfadiazine and Azithromycin (Pseudo partitioning coefficient were 28-3814 L kg^-1 and 21-2405 L kg^-1, respectively.) had the largest partitioning coefficient between sediment and water. In addition, pseudo partitioning coefficient of Sulfadiazine and Clindamycin were higher than the values of corresponding equilibrium partitioning constant (K_d), which would likely cause them to re-release from sediment to water. Compared to the physiochemical properties of the sediment, water quality has a greater impact on antibiotic partitioning. We found that the partitioning of antibiotics was significantly positively correlated with salinity, suspended solids, pH, NH₄⁺-N and Zn; and negatively correlated with temperature, dissolved oxygen, PO₄^3-, chemical oxygen demand, NO₃^--N, oil, Cu and Cd. The ecological risks of antibiotics in water and sediment were also evaluated for revealing their relationship with the concentration partitioning of antibiotics. Results showed that the target antibiotics mainly pose ecological risks to Daphnia with low and median chronic toxicity risk rather than fish and green algae. The antibiotics in sediment were more chronically toxic to Daphnia than that in water. The risk quotient ratio of sediment and water (RQ_s/RQ_w) ranged from 0 to 1154.0, which were exactly opposite of the values of organic carbon normalized partition coefficient (K_oc), suggesting that the physical properties of antibiotics drove the ecological risk allocation of antibiotics in sediment and water.

Arsenic and chlordecone contamination and decontamination toxicokinetics in Sargassum sp

Massive Sargassum sp. beachings have been occurring on Caribbean shores since 2011. The sargassum involved in such events are S. fluitans and S. natans, two drifting species whose proliferation has been observed in the southern North Atlantic Ocean. Both for reasons of environmental and sanitary assessment and repurposing, Sargassum sp. that is ashore piled up on beaches and decaying must be studied. Studies are required because of the concerning content of pelagic arsenic reported in the literature. They are also needed owing to Sargassum sp. contamination subsequent to historical pollution in the French West Indies by chlordecone, an insecticide used against the banana weevil Cosmopolites sordidus. The present study aims to describe the contamination and decontamination toxicokinetics of arsenic and chlordecone for Sargassum sp. stranding on shores and shallows in the Caribbean, in order to support the decision-making of the authorities involved. In situ and in mesocosm experiments performed in the present study show that Sargassum sp. contamination by chlordecone is mainly done after 2 h of exposition and reaches equilibrium after a day of exposure in polluted water, but BCF study suggests that the phenomenon is not actively supported (passive soption only). Arsenic transudation is intense in the case of immerged algae both. Half of the arsenic content is transudated after 13 h at sea and will transudate until vestigial arsenic concentration. Sargassum sp. contamination by arsenic, due to phytoaccumulation offshore, is broadly homogeneous before decay, and then leaks lead rapidly to a decrease in concentration in Sargassum sp. necromass, questioning the subsequent contamination of the coastal environment.

Improved isolation and detection of toxigenic Vibrio parahaemolyticus from coastal water in Saudi Arabia using immunomagnetic enrichment

Background

Vibrio parahaemolyticus is recognized globally as a cause of foodborne gastroenteritis and its widely disseminated in marine and coastal environment throughout the world. The main aim of this study was conducted to investigate the presence of toxigenic V. parahaemolyticus in costal water in the Eastern Province of Saudi Arabia by using immunomagnetic separation (IMS) in combination with chromogenic Vibrio agar medium and PCR targeting toxR gene of species level and virulence genes.

Methods

A total of 192 seawater samples were collected from five locations and enriched in alkaline peptone water (APW) broth. One-milliliter portion from enriched samples in APW were mixed with an immunomagnetic beads (IMB) coated with specific antibodies against V. parahaemolyticus polyvalent K antisera and separated beads with captured bacteria streaked on thiosulfate citrate bile salts sucrose (TCBS) agar and CHROMagar Vibrio (CaV) medium.

Results

Of the 192 examined seawater samples, 38 (19.8%) and 44 (22.9%) were positive for V. parahaemolyticus, producing green and mauve colonies on TCBS agar and CaV medium, respectively. Among 120 isolates of V. parahaemolyticus isolated in this study, 3 (2.5%) and 26 (21.7%) isolates of V. parahaemolyticus isolated without and with IMB treatment tested positive for the toxin regulatory (toxR) gene, respectively. Screening of the confirmed toxR gene-positive isolates revealed that 21 (17.5%) and 3 (2.5%) were positive for the thermostable direct hemolysin (tdh) encoding gene in strains isolated with IMB and without IMB treatment, respectively. None of the V. parahaemolyticus strains tested positive for the thermostable related hemolysin (trh) gene. In this study, we found that the CaV medium has no advantage over TCBS agar if IMB concentration treatment is used during secondary enrichment steps of environmental samples. The enterobacterial repetitive intergenic consensus (ERIC)-PCR DNA fingerprinting analysis revealed high genomic diversity, and 18 strains of V. parahaemolyticus were grouped and identified into four identical ERIC clonal group patterns.

Conclusions

The presented study reports the first detection of tdh producing V. parahaemolyticus in coastal water in the Eastern Province of Saudi Arabia.

Bioassay-based ecotoxicological investigation on marine and freshwater impact of cigarette butt littering

Despite representing an extremely relevant portion (20-40%) of worldwide coastal litter, cigarette butts are still an underestimate environmental issue of limited scientific interest. Public authorities of different countries promote active removal of cigarette butts, but the issue remains problematic in terms of aesthetic, environmental and health-related impacts. There are few studies on the environmental side-effects of smoked cigarette butt litter despite being a worldwide issue. In this work, two ecotoxicological bioassay batteries were adopted to evaluate the environmental consequences of cigarette butt water-soluble ingredient release in both marine water and freshwater. Marine assays were generally more affected compared to freshwater. Interesting outcomes were observed with crustacean tests, showing a lower effect of smoked cigarette butt leachate when tested at maximum concentration. This finding were supported by heartbeat measures of Daphnia magna, which were accelerated at 100% of smoked cigarette butt leachate.

Can shellfish be used to monitor SARS-CoV-2 in the coastal environment?

The emergence and worldwide spread of SARS-CoV-2 raises new concerns and challenges regarding possible environmental contamination by this virus through spillover of human sewage, where it has been detected. The coastal environment, under increasing anthropogenic pressure, is subjected to contamination by a large number of human viruses from sewage, most of them being non-enveloped viruses like norovirus. When reaching coastal waters, they can be bio-accumulated by filter-feeding shellfish species such as oysters. Methods to detect this viral contamination were set up for the detection of non-enveloped enteric viruses, and may need optimization to accommodate enveloped viruses like coronaviruses (CoV). Here, we aimed at assessing methods for the detection of CoV, including SARS-CoV-2, in the coastal environment and testing the possibility that SARS-CoV-2 can contaminate oysters, to monitor the contamination of French shores by SARS-CoV-2 using both seawater and shellfish. Using the porcine epidemic diarrhea virus (PEDV), a CoV, as surrogate for SARS-CoV-2, and Tulane virus, as surrogate for non-enveloped viruses such as norovirus, we assessed and selected methods to detect CoV in seawater and shellfish. Seawater-based methods showed variable and low yields for PEDV. In shellfish, the current norm for norovirus detection was applicable to CoV detection. Both PEDV and heat-inactivated SARS-CoV-2 could contaminate oysters in laboratory settings, with a lower efficiency than a calicivirus used as control. Finally, we applied our methods to seawater and shellfish samples collected from April to August 2020 in France, where we could detect the presence of human norovirus, a marker of human fecal contamination, but not SARS-CoV-2. Together, our results validate methods for the detection of CoV in the coastal environment, including the use of shellfish as sentinels of the microbial quality of their environment, and suggest that SARS-CoV-2 did not contaminate the French shores during the summer season.

Exposure of coastal environments to river-sourced plastic pollution

Marine litter is a global problem which poses an increasing threat to ecosystem services, human health, safety and sustainable livelihoods. In order to better plan plastic pollution monitoring and clean-up activities, and to develop policies and programmes to deter and mitigate plastic pollution, information is urgently needed on the different types of coastal ecosystem that are impacted by land-sourced plastic inputs, especially those located in proximity to river mouths where plastic waste is discharged into the ocean. We overlayed the most current existing information on the input of plastic to the sea from land-based sources with maps of coastal environments and ecosystems. We found an inverse relationship exists between coastal geomorphic type, plastic trapping efficiency and the mass of plastic received. River-dominated coasts comprise only 0.87% of the global coast and yet they receive 52% of plastic pollution delivered by fluvial systems. Tide-dominated coasts receive 29.9% of river-borne plastic pollution and this is also where mangrove and salt marsh habitats are most common. Wave-dominated coasts receive 11.6% of river-borne plastic pollution and this is where seagrass habitat is most common. Finally, rocky shores comprise 72.5% of the global coast, containing fjords and coral reefs, while only receiving 6.4% of river-borne plastic pollution. Mangroves are the most proximal to river-borne plastic pollution point sources of the four habitat types studied here; 54.0% of mangrove habitat is within 20 km of a river that discharges more than 1 t/yr of plastic pollution into the ocean. For seagrass, salt marsh and coral reefs the figures are 24.1%, 22.7% and 16.5%, respectively. The findings allow us to better understand the environmental fate of plastic pollution, to advance numerical models and to guide managers and decision-makers on the most appropriate responses and actions needed to monitor and reduce plastic pollution.

Types of coastlines and the evacuees' mental health: A repeated cross-sectional study in Northeast Japan

Although the health risks and benefits of coastal areas have long been researched, these effects of the different types of coastlines have rarely been explored on the evacuees living near the coast, in a post-disaster context. Thus, this study aimed to explore, with the passing of years after a disaster, what kind of coastline is a useful public health resource as a post-disaster reconstruction approach in coastal environments that have suffered significantly from the tsunami disaster in northeast Japan in 2011. This study compared the evacuees' mental health based on proximity to the coast and the types of coastlines (artificial, semi-natural, and natural). Data were drawn from the Miyagi Prefectural Government surveys, which targeted almost all evacuees of the 2011 Great East Japan Earthquakes and Tsunami (n = 96,203). We applied a pooled Poisson regression model to a repeated cross-sectional dataset of evacuees' mental health between 2012 and 2016. Moderate psychological distress, measured via the Kessler Psychological Distress Scale (K6) score, was the dependent variable, while proximity to the coast and type of coastline were the independent variables. The estimated main effects of type of coastline indicated that overall associations between K6 ≥5 and all types of coastlines within a 1.6 km buffer of participants' residential space were not statistically significant (p > 0.05). However, among types of coastlines, the interaction terms of semi-natural coastline × year (2015 and 2016) were significantly associated with lower incidence rate ratios (IRR), which decreased in 2015 and 2016 (IRR: 0.88, 95%CI: 0.79-0.98; IRR: 0.78, 95%CI: 0.68-0.90, respectively). Further, we computed the marginal effects of coastline types for each year to observe differences in the impact on moderate psychological distress depending on different accessible coastline types within a distance of 1.6 km from the participants' living space. We found that, after the revision of the coastal act in 2014, the moderate mental stress of participants who lived around semi-natural coastlines significantly tended to be low (dy/dx: -0.04, 95%CI: -0.08-0.01 in 2015; dy/dx: -0.07, 95%CI: -0.11-0.04 in 2016). This finding can encourage policymakers to manage coastal areas with green infrastructure in the post-disaster reconstruction sustainably.

Wave energy assessment under climate change through artificial intelligence

The implementation of renewable energies is among the main challenges that we are confronting in the present situation of climate change. In this work, an artificial neural network (ANN) is optimized and used to assess the wave energy resource available to a wave farm over its service life. We select as case study a stretch of coastline in southern Spain. Different ANN architectures and training algorithms are tested for a dataset in deep water composed by: three values of significant wave height, four values of peak period, two values of incoming wave direction, three astronomical tide values, three storm surge values and three values of sea level rise induced by climate change. These deep-water sea states were propagated using a numerical model (Delft3D-Wave) and results were obtained at 176 locations. Thus, more than 114,000 data were used to train and test the ANNs. Once validated, the ANN was used to assess the cumulative wave energy at 704 locations during a 25-year period for three scenarios of rise in sea level according to the Intergovernmental Panel on Climate Change (IPCC) reports: present situation, pessimistic IPCC projection and optimistic IPCC projection. According to the results, the cumulative wave energy in the case study increases with increasing water depths. The greatest values of cumulative wave energy are reached at great depths off a shoreline horn and a port. Importantly, the rise in sea level will induce an increase in the wave energy resource. The ANN developed in this work allows the quantification of wave energy over long-term periods, reducing the computational cost, as well as the choice of the best locations for wave farms considering the effects of climate change.

The influence of summer hypoxia on sedimentary phosphorus biogeochemistry in a coastal scallop farming area, North Yellow Sea

In situ field investigations coupled with laboratory incubations were employed to explore the surface sedimentary phosphorus (P) cycle in a mariculture area adjacent to the Yangma Island suffering from summer hypoxia in the North Yellow Sea. Five forms of P were fractionated, namely exchangeable P (Ex-P), iron-bound P (FeP), authigenic apatite (CaP), detrital P (De-P) and organic P (OP). Total P (TP) varied from 13.42 to 23.88 μmol g^-1 with the main form of inorganic P (IP). The benthic phosphate (DIP) fluxes were calculated based on incubation experiments. The results show that the sediment was an important source of P in summer with ~39% of the bioavailable P (BioP) recycled back into the water column. However, the sediment acted a sink of P in autumn. The benthic DIP fluxes were mainly controlled by the remobilizing of FeP, Ex-P and OP under contrasting redox conditions. In August (hypoxia season), ~0.92 μmol g^-1 of FeP and ~0.52 μmol g^-1 of OP could be transformed to DIP and released into water, while ~0.36 μmol g^-1 of DIP was adsorbed to clay minerals. In November (non-hypoxia season), however, ~0.54 μmol g^-1 of OP was converted into DIP, while ~0.55 μmol g^-1 and ~0.28 μmol g^-1 of DIP was adsorbed to clay minerals and bind to iron oxides. Furthermore, scallop farming activities also affected the P mobilization through biological deposition and reduced hydrodynamic conditions. The burial fluxes of P varied from 11.67 to 20.78 μmol cm^-2 yr^-1 and its burial efficiency was 84.7-100%, which was consistent with that in most of the marginal seas worldwide. This study reveals that hypoxia and scallop farming activities can significantly promote sedimentary P mobility, thereby causing high benthic DIP flux in coastal waters.

Nationwide monitoring of microplastics in bivalves from the coastal environment of Korea

Bivalves are useful bioindicators of microplastic contamination in the marine environment for several reasons, such as extensive filter feeding activity, broad geographical distribution, and limited movement capability. This study conducted a nationwide monitoring of microplastic pollution along the Korean coasts using filter-feeding bivalves (including oyster, mussel, and Manila clam) as bioindicators to identify the national contamination level and characteristics of microplastics. Seawater sample was collected from the same sampling stations of oyster and mussel for comparison. Microplastics were widely distributed in both coastal bivalves and waters with mean concentrations of 0.33 ± 0.23 n/g (1.21 ± 0.68 n/individual) in oyster/mussel, 0.43 ± 0.32 n/g (2.19 ± 1.20 n/individual) in Manila clam, and 1400 ± 560 n/m³ in seawater. Despite the lack of significant relationship in the abundance of microplastics, their dominant features such as size, shape, color and polymer type were similar between bivalves and seawater. Fragments (69% for oyster/mussel, 72% for Manila clam, and 77% for seawater), particles smaller than 300 μm (96% for oyster/mussel, 83% for Manila clam, and 84% for seawater) and colorless (79% for oyster/mussel, 85% for Manila clam, 75% for seawater) were the dominant shape, size and color, respectively. The major polymer types were polypropylene, polyethylene, and polyester. The microplastic level in bivalves was relatively high in urbanized areas with a wide diversity of polymer types compared with those in non-urbanized areas, and the proportion of polystyrene in the Korean samples was abundant compared with other regions due to wide use of polystyrene products in Korea. Our result suggests that microplastic contamination is widespread in the Korean coastal environment, and bivalves can reflect the microplastic pollution characteristics of the surrounding waters where they live.

Risk and vulnerability assessment in coastal environments applied to heritage buildings in Havana (Cuba) and Cadiz (Spain)

In this paper, diagnostic tools are utilized to conduct a vulnerability analysis of monuments located in a coastal environment in accordance with a raft of standards drawn up by the International Organization for Standardization (ISO) 31000, in order to identify the main risks for Cultural Heritage in Havana (Cuba) and Cadiz (Spain). Vulnerability analysis is based on a Leopold matrix, which models the relationship between major hazards and pathologies in order to evaluate coastal influence and the risks for the conservation of cultural heritage. The quantitative matrix allows for a cause-effect analysis to be conducted for the main scenarios, related to the state of conservation. These relationships are a key step in risk assessment and treatment strategies. Major hazards have been identified by different public bodies and agencies to provide information about the probability and intensity of these variables in the vulnerability matrix. The combination of vulnerability index assessment, which depends on intrinsic variables and environmental scenarios, and knowledge of the main hazards in Havana and Cadiz, has provided useful tools to conduct risk assessments for cultural heritage conservation in coastal environments, where climate conditions, geomorphology and social issues are the main hazards, while vulnerability is associated with conservation plans. These tools provide information that will enable decision-makers in different coastal environments to prioritize strategies for cultural heritage preservation.

Behavior of metallurgical zinc contamination in coastal environments: A survey of Zn from electroplating wastes and partitioning in sediments

The contamination of coastal environments by metallurgical wastes involves multiple biogeochemical processes; accordingly, understanding metal behavior and risk evaluation of contaminated areas, such as Sepetiba Bay (Rio de Janeiro, Brazil), remains challenging. This study coupled Zn isotopic analyses with sequential extractions (BCR) to investigate the mechanisms of Zn transfer between legacy electroplating waste and the main environments in Sepetiba Bay. This metallurgical waste showed a light bulk isotopic signature (δ^66/64Znbulk_JMC = +0.30 ± 0.01‰, 2 s, n = 3) that was not distinct from the lithogenic geochemical baseline, but was different from signature of mangrove sediment considered as anthropogenic end member (δ^66/64Zn_JMC = +0.86 ± 0.15‰) in a previous isotopic study in this area. Zn isotopic compositions of sediment samples (ranging from +0.20 to +0.98‰) throughout the bay fit a mixing model involving multiple sources, consistent with previous studies. In the metallurgic zone, the exchangeable/carbonate fraction (ZnF1) exhibited high Zn concentrations (ZnF1 = 9840 μg g^-1) and a heavy isotopic composition (δ^66/64ZnF1_JMC = +1.10 ± 0.01‰). This finding showed that, in some cases, the bulk isotopic signature of waste is not the most relevant criterion for evaluating trace metal dispersion in the environment. Indeed, based on the BCR, it was observed that part of the anthropogenic metallurgical Zn was redistributed from the exchangeable/carbonate fraction in the waste to the surrounding mangrove sediment. Then, this contaminated sediment with heavy δ^66/64Zn values was exported to other coastal environments. In Sepetiba Bay, contaminated sediments revealed a large concentration of ZnF1 fraction (up to 400 μg g^-1) with a heavy Zn isotopic signature. This signature also matched the Zn isotopic signature of oysters in Sepetiba Bay reported by other studies; hence, measurement of the isotopic exchangeable/carbonate fraction has important implications for tracing the transfer of anthropogenic Zn to biota.

Long-term quality record (1996-2018) of coastal sediments at the complex industrial site along the Jordanian coast of the Gulf of Aqaba

To evaluate the effect of the industrial activities on the sediment quality, we investigated long-term records of physical and chemical properties of bottom-surface sediments from a complex industrial site along the Jordanian coast of the Gulf of Aqaba. Sediment samples were collected from 10 m depth once a year from six different stations (S1-S6) and analyzed for grain size, loss on ignition (LOI), organic carbon (OC), hydrogen sulfide (H₂S), total nitrogen (TN), total phosphorus (TP), and heavy metal contents. Temporal variations show a constant/decreasing trend for H₂S, OC, and LOI, whereas an increasing trend for TN and TP was observed. Heavy metal concentrations reveal almost constant trends over time for Cd, Cu, and Zn and a decreasing trend for Cr and Pb. Statistical analysis indicates that the differences between the different sampling stations were insignificant for almost all variables. However, some differences were observed, as the highest values were recorded in S3 and the lowest values in S1. The textural proprieties show no significant variation among sites. As a result, the sediment quality at the industrial site is comparable with that in other sites along the northern Gulf of Aqaba. Sediments at the industrial site appear to have attained steady-state equilibrium where basic environmental parameters are insignificantly modified from the baseline values of the area. The decreasing trend observed over time indicates a significant improvement in the environmental quality attributed to the stringent implementation of environmental regulation in Aqaba (e.g., zero discharge policy).

The impact of anthropogenic activity at the tropical Sergipe-Poxim estuarine system, Northeast Brazil: Fecal indicators

The individual concentrations and sources of sterols in sediments samples collected in two periods 2017 (dry period /March and rainy period/August) were determined along with the Sergipe-Poxim estuarine system, Aracaju, Brazil. The individual sterols concentration ranged from 135 to 21,746 ng g^-1 (March) and 191 to 144,748 ng g^-1 (August) and the distribution was mainly dominated by β-sitosterol in both periods with 37.2% (March) and 70.8% (August) of the total sterols found. In all the sampling sites, the coprostanol levels were higher than 100 ng g¹ (March) and 500 ng g^-1 (August), indicating sewage contamination. Diagnostic ratios between sterols suggested the predominance of sewage sources. Pearson correlation assessed a correlation significant (March) and negligible (August) between coprostanol concentration levels and organic matter. The principal component analysis (PCA) showed that the sterols levels influenced strongly C1, as well as C2 distinguished between the plant sterols and from sewage.

Bioremediation potential of Sargassum sp. biomass to tackle pollution in coastal ecosystems: Circular economy approach

During the past years, the ecological integrity and biodiversity of marine ecosystems have been highly threatened due to the controlled or uncontrolled release of high concentrations of pollutants generated through anthropogenic activities. The occurrence of environmentally related hazardous pollutants, such as toxic elements, and recalcitrant compounds in various environmental matrices has raised increasing concern. Different technologies have been developed for efficient removal and complete mitigation or degradation of these toxic elements from the aquatic environment. Among them, biosorption and bioaccumulation by renewable and biodegradable sources are of supreme interest and have not been reviewed much. For instance, the invasive seaweed Sargassum sp. has been spotted as a cost-effective natural material to capture targeted pollutants from the coastal ecosystem, which is currently becoming a pressing problem, around the globe, due to its unusual proliferation near tropical shores. This review is an effort to cover the left behind gap to present the multifunctional potentialities of Sargassum sp. biomass. Herein, salient information is given to highlight the potential of Sargassum sp. biomass for environmental decontamination with particular focus to coastal ecosystems. Bioremediation mechanisms, challenges of implementation and factors involved in adsorption and absorption of pollutants by seaweeds are also discussed in this review. Against this background, a circular economy perspective is given for the integrated use of the algal raw material. The up-taken pollutants can be recovered and reintegrated into the value chain of industrial processes, while residual biomass is refined to obtain added-value products as bioactive compounds with potential applications for biofuel, agriculture, cosmetics, nutraceutical, pharmaceutical industries among others, to make the most of renewable resources.

Enrichment behavior of contemporary PAHs and legacy PCBs at the sea-surface microlayer in harbor water

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the sea-surface microlayer (SML) and sub-surface water (SSW) were analyzed in and around Kaohsiung Harbor. The results confirm SML enrichments for PAHs, but PCBs less significantly, since PAHs are still produced while PCBs had banned years ago. However, PCBs still leak to the environment from contaminated sites. The results showed the sources and transport of PAHs and PCBs were different, but both are enriched in the SML. Total particulate PAHs at most sites are below the toxicity thresholds, with a few individual PAHs between the effects range-low and effect range-median even higher than the effect range-median. Total particulate PCBs might cause occasionally adverse effects in sensitive species and pose a risk to the organisms. The particulate phase in the SML poses a higher risk to the marine ecosystem than in the SSW although not all organisms will make direct use of the microlayer. Principal component analysis (PCA) of PAHs indicated the important contribution of traffic engine emission in the particulate samples of the SML and SSW and revealed that probably the petroleum pollutants are a predominant source for the dissolved phase. Cluster analysis revealed that PAH-PCB patterns in the river and anchorage channels were different to those in the wetlands and open harbor. However, PCA of PCBs showed differences in the congener profiles for the two phases, with highly chlorinated PCBs more abundant in particles, while less chlorinated PCBs were more abundant in dissolved.

Antibiotics in coastal water and sediments of the East China Sea: Distribution, ecological risk assessment and indicators screening

The distribution of 77 antibiotics in the coastal water and sediment from 3 bays of the East China Sea was investigated. There were 43 and 25 antibiotics detected with total concentrations of 30.8-2106.1 ng/L and 2.2-99.9 ng/g in water and sediment, respectively. Approximately 83.0% and 85.4% of the individual antibiotic concentrations were lower than 5.0 ng/L in water and 1.0 ng/g in sediment. Clindamycin (1.2-1507.9 ng/L, mean 183.8 ng/L) and erythromycin (ND-45.2 ng/g, mean 3.4 ng/g) were the most abundant in water and sediment, respectively. Ecological risk assessment revealed that the joint toxicity was enhanced when multiple antibiotics were present simultaneously. A decrease in the total antibiotic concentration and the ecological risk in water was observed from nearshore to offshore. Three antibiotics (sulfamethoxypyridazine, sulfamethoxazole and cinoxacin) were selected to be prioritized based on ecological risks for antibiotics monitoring and management of the coastal water in the East China Sea.

Trace metal speciation in North Sea coastal waters

Most trace metals exhibit a dual role in marine waters, acting as nutrients at low concentration and being toxic at high concentration. But besides concentration range, speciation is also an important factor. They both show both seasonal and spatial variations. A thorough comparison between total dissolved and particulate concentrations estimated from manual sampling and an assessment of the bioavailability using Diffusive Gradients in Thin Films (DGT) has been performed in this work for Cd, Co, Cu, Ni and Pb, at several sampling points of the Belgian Coastal Zone (BCZ). Additional information to trace back the origin and identify the anthropogenic fingerprint of Suspended Particulate Matter (SPM) was measured using stable carbon isotope measurements in particulate organic matter. Our results show that: (i) particulate and total dissolved metal concentrations are higher at two stations, one in the harbor of Oostende and one offshore; (ii) dissolved and particulate trace metal concentrations do not correlate with the dissolved labile fractions; and (iii) SPM in the harbor zone is likely from allochthonous sources, while in the offshore station marine origin has been evidenced. Our results indicate that, even though contamination is higher in the harbor zones, the trace metal toxicity, which is linked to the metal bioavailability, is most likely not higher than in the open sea. However, with increasing acidification of the ocean, a shift from particulate to dissolved phase might lead to increasing adverse effects on the coastal environment.

Plasticrusts: A new potential threat in the Anthropocene's rocky shores

Plastic debris is one of the most extensive pollution problems our planet is facing today and a particular concern for marine environment conservation. The dimension of the problem is so large that it is possible our current era will generate an anthropogenic marker horizon of plastic in earth's sedimentary record. Here we present a new type of plastic pollution, the 'plasticrusts', plastic debris encrusting the rocky surface, recently discovered in the intertidal rocky shores of a volcanic Atlantic island. The potential impact that these new 'plasticrusts' may have needs to be further explored, as e.g. potential ingestion by intertidal organisms could suppose a new pathway for entrance of plastics into marine food webs. Consequently, its inclusion as a potential new marine debris category in management and monitoring actions should be pondered.

Emerging per- and polyfluoroalkyl substances (PFASs) in surface water and sediment of the North and Baltic Seas

Along with the phase-out of legacy long-chain perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs) and their precursors, attention has been drawn to emerging per- and polyfluoroalkyl substances (PFASs). This study is aimed at investigating the importance of selected emerging PFASs as pollutants in European coastal environments and a possible transition from legacy long-chain PFCAs and PFSAs to replacement compounds. Therefore, the spatial distribution of 29 PFASs was analysed in surface water and sediment of the North and Baltic Seas sampled in 2017. Levels of the replacement compound HFPO-DA were approximately three times higher than those of its predecessor PFOA in surface water from the North Sea, which is characterised by the influence of point sources and constant exchange with open water. Reanalysis of sample extracts from the last decade showed that HFPO-DA had already been present in 2011, when it had not yet been in focus. In the Baltic Sea with a limited water exchange and dominance of diffuse sources, the proportion of HFPO-DA was negligible, whereas long-chain PFCAs and PFSAs still contributed to ∑PFASs with about 30%. The emerging cyclic compound perfluoro-4-ethylcyclohexanesulfonate (PFECHS), which has not yet been reported in European coastal environments, was detected in 86% of the Baltic Sea samples. Influenced by sediment characteristics in addition to source-specific contributions, the spatial distribution of PFASs in surface sediments was more variable than for water samples. The linear isomer of the long-chain legacy substance PFOS was the predominant compound found over the entire study area. Of the emerging PFASs, 6:6 and 6:8 perfluoroalkyl phosphinic acids (PFPiAs) were identified close to potential industrial inputs and in sedimentation areas. The results show that particular emerging PFASs play a relevant role in the investigated coastal environments and that a shift to replacements is dependent on sources and geographical conditions.

Impact of environmental gradients on the abundance and diversity of planktonic fungi across coastal habitats of contrasting trophic status

Fungal communities in the coastal waters have long been known to be dynamic with a significant role in organic matter cycling. However, the effects of environmental gradients on their community structures are poorly described. Here we studied three coastal sites off the South China Sea, namely Pearl River Estuary (PE), Shenzhen Bay (SB), and Daya Bay (DB) with contrasting trophic status and heterogenous local influences. Environmental analysis of these sites suggested higher nutrient and low salinity levels at PE and SB with wide variability compared to DB. Average molecular abundances (18S rRNA gene copy numbers) at sites PE (1.05 ± 0.27 × 10⁷ copies L^-1) and SB (1.2 ± 0.69 × 10⁷ copies L^-1) were similar and significantly higher (P < 0.05) than that at site DB (5.5 ± 9.5 × 10⁵ copies L^-1). Although planktonic fungi were molecularly abundant at the three sites, live fungal biomass based on ergosterol assay was detected only at some stations of PE and SB. Both molecular abundance and live biomass were significantly correlated with chemical oxygen demand, nutrients, and phytoplankton biomass, supporting their role in detritus turnover. The fungal communities were unprecedently diverse with the ubiquitous dominance of Dikarya and the occasional predominance of Glomeromycota, Mucoromycota, Mortierellomycota, and Chytridiomycota. A total of 24 classes, 46 orders, 71 families, 59 genera, and eight species were classified within the eight detected phyla, including the new finding of ascomycetous class Geoglossomycetes in coastal waters. Salinity and nitrate were the significant (r² = 0.70, P < 0.05) factors that determined the β-diversity of fungal communities. Overall, this study suggests that although planktonic fungi are ubiquitous in coastal habitats, their molecular abundances and diversities (both α and β) are significantly determined by environmental gradients, particularly the salinity, COD and nitrate levels of coastal waters.

Adverse effects of non-biodegradable and compostable plastic bags on the establishment of coastal dune vegetation: First experimental evidences

Non-biodegradable and compostable plastic bags on beaches negatively affect the development of coastal dune vegetation by drastically reducing seedling emergence and growth.

Identification of putative key genes for coastal environments and cold adaptation in mangrove Kandelia obovata through transcriptome analysis

Mangrove forests are an important contributor to the coastal marine environment. They have developed unique adaptations to the harsh coastal wetland, yet their geographic distribution is limited by environmental temperature. The adaptive strategies of mangrove at the molecular level, however, have not been addressed. In the present work, transcriptome analyses were performed on different cold damaged plants of a mangrove species, Kandelia obovata. From the samples collected in the field after a cold stress, we found that distinct expression profiles of many key genes are related to extreme temperature responses. These include transcription factors such as WRKY and bHLH, and other genes encoding proteins like SnRK2, PR-1, KCS, involving in the pathways of plant hormones, plant-pathogen interactions, and long chain fatty acid synthesis. We also examined the transcriptomes of eight tissues of K. obovata to identify candidate genes involved in adaptation and development. While stress-responsive genes were globally expressed, tissue-specific genes with diverse functions might be involved in tissue development and adaptability. For examples, genes encoding CYP724B1 and ABCB1 were specifically expressed in the fruit and root, respectively. Additionally, 26 genes were identified as positively selected genes in K. obovata, six of them were found to be involved in chilling stress response, seed germination and oxidation-reduction processes, suggesting their roles in stressful environment adaptation. Together, these results shed light into the K. obovata's natural responses to cold snaps at the molecular level, and reveal a global gene expression portrait across different tissues. It also provides a transcriptome resource for further molecular ecology studies and conservation planning of this and other mangrove plants in their native and adopted environments.

Arsenic enrichment in sediments and beaches of Brazilian coastal waters: A review

High concentrations of total arsenic (As), even above the Brazilian legislative threshold for marine sediments of 70 mg kg^-1, were found in beach sands and near-shore surface sediments. Two mechanisms (anthropogenic activities and sedimentary processes in the coastal waters) are responsible for this contamination. The anthropogenic impact includes releases from metallurgical plants, phosphate fertilizer plants and gold and iron mining. In the coastal area sedimentary processes redistributed the As from the sediment into the porous structure of calcareous marine algae. These enriched calcareous algae are transported over time to the beach by wave action. As in the Brazilian coastal environment, increased As levels were also observed in other coastal environments of South America such as Rio Loa (Chile), Barbacoas Bay (Colombia) and the Southern Pampa region (Argentina). Finally, arsenic levels in fish from Brazilian coastal waters and North Sea, which is also an As-contaminated area, were compared. In both areas, short term health effects from fish consumption are not expected, but a lifetime cancer risk cannot be excluded.

Candida tropicalis geographic population structure maintenance and dispersion in the coastal environment may be influenced by the climatic season and anthropogenic action

Candida tropicalis is a pathogenic yeast with worldwide recognition as the second or third more frequently isolated species in Latin America, for both superficial and systemic infections. Because of its high prevalence, and growing clinical interest, it is essential to understand genetic variability patterns of this important Candida species in the tropics. Besides belonging to the human normal microbiota, C. tropicalis may be found in other warm blood animals and in the environment, including water and sand of beaches. The aims of the present study were to evaluate genotypic and phenotypic variability of 62 isolates of C. tropicalis obtained from the coastal environment in Northeast Brazil using microsatellite and MALDI-TOF/MS comparisons. There was a relatively low correspondence between these typing techniques employed. Therefore, further studies are needed to consolidate the use of MALDI-TOF/MS as a yeast typing tool. Nevertheless, the two methods employed demonstrated the heterogeneity of C. tropicalis in a coastal environment. We also found relative maintenance of the population structure within the same season, which may reinforce the idea that this species presents the potential to remain in the environment for a long period of time. In addition, highly related strains were found within different geographic points of collection, demonstrating that this strain may be dispersed at long distances, probably influenced by anthropogenic actions and driven by the sea tides and wind.

Distribution and fate of 129I in the seabed sediment off Fukushima

In this study, seabed sediment was collected from 26 stations located within 160 km from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) during the 2 years which followed the FDNPP accident of March 2011 and the concentrations of ¹²⁹I and ¹³⁷Cs were measured. By comparing the distribution of these two radionuclides with respect to their different geochemical behaviors in the environment, the transport of accident-derived radionuclides near the seafloor is discussed. The concentration of ¹²⁹I in seabed sediment recovered from offshore Fukushima in 2011 ranged between 0.02 and 0.45 mBq kg^-1, with ¹²⁹I/¹³⁷Cs activity ratios of (1.9 ± 0.5) × 10^-6 Bq Bq^-1. The initial deposition of ¹²⁹I to the seafloor in the study area was 0.36 ± 0.13 GBq, and the general distribution of sedimentary ¹²⁹I was established within 6 months after the accident. Although iodine is a biophilic element, the accident-derived ¹²⁹I negligibly affects the benthic ecosystem. Until October 2013, a slight increase in activity of ¹²⁹I in the surface sediment along the shelf-edge region (bottom depth: 200-400 m) was observed, despite that such a trend was not observed for ¹³⁷Cs. The preferential increase of the ¹²⁹I concentrations in the shelf-edge sediments was presumed to be affected by the re-deposition in the shelf-edge sediments of ¹²⁹I desorbed from the contaminated coastal sediment. The results obtained from this study indicate that ¹²⁹I/¹³⁷Cs in marine particles is a useful indicator for tracking the secondary transport of accident-derived materials, particularly biophilic radionuclides, from the coast to offshore areas.

Plastic pellets, meso- and microplastics on the coastline of Northern Crete: Distribution and organic pollution

Plastic pollution in the marine environment is one of the foremost environmental problems of our time, as it affects wildlife and human health both directly and indirectly through the effects of contaminants carried by microplastics. This study investigates the temporal and spatial distribution of plastic pellets and fragments in sandy beaches along the coastline of Northern Crete, during 2013. Their densities varied throughout the year in each beach, with highest densities during the summer and towards the upper parts of the beaches. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) sorbed on microplastics sampled from nine sandy beaches of Northern Crete was quantified using Gas chromatography - Ion Trap Mass Spectrometry (GC-ITMS). PAHs concentrations ranged from non-detectable levels to 1592 ng/g and fluctuated between sampling periods. Based on the observed patterns of meso- and microplastics distribution, practical guidelines are proposed to minimize the entrance of microplastics into the seawater wherefrom they are exceptionally difficult to collect, if mitigation actions are to be applied.

Single and combined metal contamination in coastal environments in China: current status and potential ecological risk evaluation

With the development of industrialization and urbanization, metal and metalloid pollution is one of the most serious environmental problems in China. Current contamination status of metals and metalloid and their potential ecological risks along China's coasts were reviewed in the present paper by a comprehensive study on metal contents in marine waters and sediments in the past few decades. The priority metals/metalloid cadmium (Cd), mercury (Hg), chromium (Cr), lead (Pb), and arsenic (As), which were the target elements of the designated project "Comprehensive Prevention and Control of Heavy Metal Pollution" issued by the Chinese government in 2011, were selected considering their high toxicity, persistence, and prevalent existence in coastal environment. Commonly used environmental quality evaluation methods for single and combined metals were compared, and we accordingly suggest the comprehensive approach of joint utilization of the Enrichment Factor and Effect Range Median combined with Pollution Load Index and Mean Effect Range Median Quotient (EEPME); this battery of guidelines may provide consistent, internationally comparable, and accurate understanding of the environment pollution status of combined metals/metalloid and their potential ecological risk.

Mapping toxic mineral contamination: the southern oyster drill, S. haemastoma (L., 1767), as evaluable sentinel species

The nickel, chromium, arsenic, cadmium, and lead content have been evaluated, by ICP-MS, in digestive gland of the amphiatlantic gastropod Stramonita haemastoma, sampled along the highly anthropized Gulf of Milazzo (Central Mediterranean). Concentrations notably higher than those reported in literature for other Mediterranean Muricidae have been recorded. The results also indicated a different impact in different sites, according to distribution and typology of human activities, whilst recorded seasonal variations might relate with rapid metabolic response. Such preliminary results suggest S. haemastoma may be considered a promising sentinel species for inorganic contamination in marine environment, especially in terms of short-medium-term exposure.

Presence of trace elements in the silverside Odontesthes argentinensis

The silverside Odontesthes argentinensis is an economically significant resource for commercial fisheries in South America. We evaluated the presence of trace elements in the stomach content and fish tissues (muscle and otoliths) of O. argentinensis. In addition, we assessed the presence of trace elements in its prey (zooplankton) and in seawater in a coastal temperate area. The most abundant trace elements found in the water, zooplankton, stomach content, and fish tissues (muscle and otoliths) constituted of Ba, Mn, Sr and Zn, while Cd, Cu and Pb were observed in lower concentrations. We concluded that O. argentinensis specimens captured from the environment, within the length range analyzed for muscle samples (total length: <21cm), are deemed fit for human consumption because the concentrations of trace elements mostly meet the standards established in the Argentine Food Code. The information obtained in this study is vital for O. argentinensis farming in closed systems.

Remediation of contaminated lands in the Niger Delta, Nigeria: Prospects and challenges

Contamination of the total environment (air, soil, water and biota) by crude oil has become a paramount interest in the Niger Delta region of Nigeria. Studies have revealed variable impacts of oil toxicity on the environment and exposed populations. The revelation gained much international attention in 2011 with the release of Environmental Assessment of Ogoniland report by the United Nations Environment Programme (UNEP). This has up scaled local and international pressures for urgent clean-up and restoration of degraded bio-resource rich environments of the Niger Delta, starting from Ogoniland. Previous remediation attempts in the area had failed due to erroneous operational conclusions (such as conclusions by oil industry operators that the Niger Delta soil is covered by a layer of clay and as such oil percolation remains within the top soil and makes remediation by enhanced natural attenuation (RENA) suitable for the region) and the adoption of incompatible and ineffective approaches (i.e. RENA) for the complex and dynamic environments. Perennial conflicts, poor regulatory oversights and incoherent standards are also challenges. Following UNEP recommendations, the Federal Government of Nigeria recently commissioned the clean-up and remediation of Ogoniland project; it would be novel and trend setting. While UNEP outlined some measures of contaminated land remediation, no specific approach was identified to be most effective for the Niger Delta region. Resolving the technical dilemma and identified social impediments is the key success driver of the above project. In this paper, we reviewed the socio-economic and ecological impacts of contaminated land in the Niger Delta region and the global state-of-the-art remediation approaches. We use coastal environment clean-up case studies to demonstrate the effectiveness of bioremediation (sometimes in combination with other technologies) for remediating most of the polluted sites in the Niger Delta. Bioremediation should primarily be the preferred option considering its low greenhouse gas and environmental footprints, and low-cost burden on the weak and overstretched economy of Nigeria.