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• Composite TiO 2 /SiO 2 films were prepared by sol-gel and ink-jet printing. • Hydrophobic TiO 2 /SiO 2 were more efficient than hydrophilic ones. • Autochthonous bacteria are significantly more resistant to SODIS than not autochthonous. • Decrease of photocatalytic activity for seawater was observed after ten cycles. Hybrid TiO 2 /SiO 2 thin films deposited by material printing technique on flexible substrates were prepared, characterized and tested for solar photocatalytic disinfection. Effect of surface hydrophilicity/hydrophobicity of printed coatings on photocatalytic disinfection was studied by means of (i) drinking water contaminated with natural consortia of fecal bacteria (gram-negative: Escherichia coli and total coliforms; gram-positive: Enterococci), and (ii) seawater containing pathogenic gram-negative bacteria (Vibrio owensii, Vibrio alfacsensis and Vibrio harveyi). Inactivation of gram-negative bacteria in drinking water with fecal contamination by solar photocatalysis was slightly more efficient than solar disinfection, while for gram-positive bacteria similar efficiency was observed. These results, in combination with observed release of titanium from coatings (detected by means of inductively coupled plasma atomic emission spectrometer), indicate that TiO 2 /SiO 2 needs further improvements for solar photocatalytic disinfection of drinking water. Efficiency of seawater disinfection towards gram-negative Vibrio spp. (Vibrio owensii, Vibrio alfacsensis and Vibrio harveyi) was significantly enhanced when TiO 2 /SiO 2 coatings were used under natural solar light. Moreover, hydrophobic thin films led to faster Vibrio spp. inactivation as compared to hydrophilic ones, which was attributed to higher bacteria adhesion on hydrophobic coatings. However, decrease of photocatalytic activity of hydrophobic TiO 2 /SiO 2 coatings was observed after ten experimental cycles mainly due to deposition of salts on the surface of photocatalyst. Generally, results of this study suggest that autochthonous bacteria such as Vibrio spp. in seawater are significantly more resistant to solar disinfection in comparison with not autochthonous bacteria such as Escherichia coli , total coliforms and Enterococci in contaminated drinking water. [ABSTRACT FROM AUTHOR]

Abstract Seasonal variability in fresh water influx and ingression of sea water establish a unique transition zone in Asia's largest coastal lagoon – the Chilika lake. The seasonal variability in water and sediment input has significant impacts on the ecosystem influencing the rate of CO 2 sequestration. We have assessed the impact of seasonal variability on CO 2 sequestration using foraminiferal analysis and grain size data end member modeling. Lake floor sediment samples were collected seasonally, besides in situ measurements of physicochemical parameters of the lake bottom water at fixed stations influenced by seasonally variable fresh and saline water influx. Low electrical conductivity, pH of bottom water and absence of calcareous foraminifera suggest that the region proximal to the river mouth has fresh water ecosystem and has very limited role in CO 2 sequestration. The region near to the sea mouth experiences high energy condition and seasonally changes from brackish to marine water ecosystem are ideal for diversification and opportunistic populations of foraminifera, but not ideal for flourishing (high population) of calcareous foraminifera. Inter-mixing of fresh and saline sea water develops fresh to brackish water conditions with medium energy condition in the interior region. These locations are away from the river and sea mouths and have high calcareous foraminifera abundances, but low diversity along with high bottom water pH suggesting seasonal variations in the sinking of CO 2. Like other shallow coastal areas, Ammonia beccarii and Ammonia tepida are the dominant calcareous species, but their smaller size suggests a seasonal stressed condition. The opening of new and artificial sea mouth has increased the inflow of sea water into the lagoon that maintains its brackish water conditions, suggested by significant increase in calcareous foraminifera abundance. The sinking of these calcareous foraminifera may enhance the rate of CO 2 sequestration and reduce degassing of dissolved carbon carried by the fresh water to the atmosphere. Graphical abstract Unlabelled Image Highlights • Variable influx of fresh and sea water causes varying lagoon ecosystem. • The ecosystem change has affected the foraminifera abundance and diversity. • Brackish region has higher calcareous foraminifera and supports sinking of CO 2. • Higher inflow of sea water maintains brackish water conditions and enhanced the rate of CO 2 sequestration. [ABSTRACT FROM AUTHOR]

Terrestrial particulate nutrients transported during flood events are known to indirectly fuel phytoplankton blooms in rivers, lakes and coastal waters, although the mechanisms are poorly understood. Quantifying the response of phytoplankton to nutrients in sediments eroded from catchments is fundamental to prioritizing areas for erosion control. This study developed a novel bioassay technique for rapidly assessing the effects of nutrients released from suspended sediments on the growth of marine and freshwater phytoplankton communities. A range of sediment slurries were placed in bioassay bottles within dialysis tubing in the presence of phytoplankton and their photosynthetic efficiency (F v /F m ) was measured over 72 h. This allowed an assessment of the effects of dissolved nutrients released from sediments without the confounding effects of suspended sediments. Chlorophyll a concentrations were also measured for comparison with F v /F m . Our study showed F v /F m was an effective method for measuring phytoplankton responses to sediment slurries. Photosynthetic efficiency was a more sensitive response metric than chlorophyll a . Applying the method to a range of suspended sediments from two tropical catchments in Australia that drain into Great Barrier Reef coastal waters, we identified a subset of sediment types (~40%) that increased F v /F m under the bioassay conditions. These sediments have the potential to stimulate marine and freshwater phytoplankton growth under the loads simulated in this study. The bioassay has the advantage of being a rapid and relatively simple method where a large number of sediments can be simultaneously tested for a phytoplankton response. To our knowledge this is the first time F v /F m has been used to assess phytoplankton responses to sediments in a bioassay. This approach advances the use of F v /F m as a sensitive indicator of phytoplankton responses to nutrients and could be used to develop indices of the relative risk various sediments pose, hence support decision making for erosion control measures. [ABSTRACT FROM AUTHOR]

Concentrations of bisphenol A (BPA) in North American and European fresh and marine surface waters and sediments were analyzed to quantify environmental levels and evaluate trends over the years 1996–2014. In North American surface water and sediment, 68% of 1030 weighted observations were below a detection limit (varied widely between studies). In Europe, 33% of 5057 weighted observations were below a detection limit. In North America and Europe, 50th percentile concentrations were 0.005 μg L-1 and 0.029 μg L-1 in freshwater and 0.0011 μg L-1 and 0.007 μg L-1 in marine water. The 95th percentile concentrations in freshwater were the same in North America and Europe at 0.30 μg L-1 and were 0.024 μg L-1 and 0.15 μg L-1 in marine water, respectively. Fiftieth percentile concentrations in North American and European freshwater sediment were 0.7 ng g-1 dry weight (dw) and 7.0 ng g-1 dw and in marine sediment were 1.0 ng g-1 dw and <0.03 ng g-1 dw, respectively. The 95th percentile concentrations were 39 ng g-1 dw and 177 ng g-1 dw in freshwater sediment and 100 ng g-1 dw and 63 ng g-1 dw in marine sediment, respectively. Most concentrations were below published chronic toxicity values or regulatory limits. BPA freshwater concentrations in both regions appear to have remain relatively unchanged over the 19 year period during which BPA production and use in polycarbonate plastic production increased significantly. There is no clear correlation between BPA or polycarbonate production and BPA levels in surface waters. [ABSTRACT FROM AUTHOR]

The genus Arcobacter comprises Campylobacter -related species, considered zoonotic emergent pathogens, the presence of which in water has been associated with fecal pollution. Discharges of fecal polluted water into the sea have been considered as one of the main reasons for the presence of Arcobacter in shellfish, and this may represent a risk for public health. In this study, the European Union shellfish food safety criteria based on levels of Escherichia coli were studied in relation to their capacity to predict the presence of Arcobacter species. In addition, the accumulation factor (AF) that measures the concentration ratio between the microbes present in the shellfish and in the water, was also studied for both bacteria. The results show that the presence of E. coli correlated with the presence of the potentially pathogenic species A. butzleri and A. cryaerophilus . However, in 26.1% of the shellfish samples (corresponding to those taken during summer months) E. coli failed to predict the presence of, for instance A. butzleri and A. skirrowii , among other species. In the rest of the samples a significant correlation between the concentration of E. coli and Arcobacter spp. (mussels and oyster; R 2 = 0.744) was found. This study indicates that the presence of E. coli can predict the presence of pathogenic Arcobacter species in shellfish samples harvested from water with temperatures lower than 26.2 °C. Consumption of shellfish collected at higher temperatures which may not be permissive to the growth of E. coli but does allow growth of Arcobacter spp., may represent a risk for consumers. [ABSTRACT FROM AUTHOR]

A mixture of polyethylene (PE), polyethylene-terephtalate (PET), polypropylene (PP) and Nylon was submerged in marine water during 12 moths. The chlorine content of these plastics was measured through the passing time. Thermobalance was used to look for differences in the thermal decomposition of the plastics during in that time interval. Degradation of PET, PP and Nylon produced changes in the weight loss curve, but behaviour of PE is confusing. Pyrolysis and combustion at 850 °C was finally performed to get knowledge of the possible differences in the emission of main gases, volatiles and semivolatiles including polycyclic aromatic hydrocarbons (PAHs), polychlorinated benzenes (ClBzs), polychlorinated phenols (ClPhs), polybrominated phenols (BrPhs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Results show that the emission of chlorinated species is somewhat not affected by the chlorine content of the plastics mix. The production of PCBs and PCDD/Fs was very low, under 4 pg WHO-TEQ/g. [ABSTRACT FROM AUTHOR]

Heterosigma akashiwo (H. akashiwo) is recognized as a harmful algal bloom (HABs) species with a global distribution, capable of posing significant threats to marine ecosystems, particularly when spread through ship ballast water. This investigation focused on elucidating the inactivation kinetics and underlying mechanism of H. akashiwo through a combined ultraviolet irradiation and peroxydisulfate (UV/PDS) process. The results demonstrated a strong synergistic effect within the UV/PDS system, resulting in an inactivation of 0.78-ln and 2.67-ln within 40 min of UV and UV/PDS processes. The principal agents accountable for inactivation were identified as sulfate radicals (•SO 4 −) and hydroxyl radical (•OH), which exhibited a synergistic effect in the UV/PDS process. Furthermore, the study observed a negatively impact of seawater pH and salinity on the efficiency of inactivation. UV/PDS caused oxidative stress on algal cells, initially involving the participation of antioxidant enzymes in counteracting cellular damage, but this protective mechanism diminished as the reaction duration extended. The UV/PDS treatment not only inflicted damage upon H. akashiwo 's photosynthetic system but also caused the extracellular release of DNA and algal organic matter (AOM) due to damaged cell membranes. Transcriptome analysis provided a molecular biology perspective on the cellular inactivation process. Upregulation of genes linked to photosynthesis and oxidative phosphorylation suggested a potential elevation in energy metabolism. In contrast, genes associated with cellular and metabolic processes, including glycolysis and the tricarboxylic acid cycle (TCA cycle), exhibited downregulation. Moreover, this treatment exerted an inhibitory influence on RNA polymerase and protein synthesis, resulting in the reduced expression of genetic information. [Display omitted] • Cell membrane of H. akashiwo was damaged by both •SO 4 − and •OH in UV/PDS. • DNA and AMO of H. akashiwo were released. • Disorder cellular metabolic processes such as TCA cycle of H. akashiwo were suppressed. • Gene expressions (RNA polymerase and protein synthesis) of H. akashiwo were disrupted. • The energy metabolism of H. akashiwo was enhanced to resist oxidative stress. [ABSTRACT FROM AUTHOR]

This study has utilized carbon and oxygen isotopic data to unravel the origin of Holocene beachrock cements of Rio Grande do Norte State coast, northeastern Brazil. The cements are exclusively constituted of Mg-calcite, with isopachous prismatic rim, equant spar, cryptocrystalline coating or pore-filling, pseudo-peloidal, radial and scalenohedral habits. The δ 18 O VPDB values of most (93%) of the samples range from −1.8‰ to +0.5‰, which are compatible with precipitation from marine waters. The δ 13 C VPDB values of these cements are +1.7 to +3.6‰ (average + 3.05‰) suggesting derivation from marine dissolved carbon. In a few cases, the Mg-calcite cement shows low δ 13 C VPDB (−7.3‰ and −7.8‰) and δ 18 O VPDB (−4.4‰ and −4.3) values, which may indicate precipitation or recrystallization of marine cements under the influence of meteoric waters. [ABSTRACT FROM AUTHOR]

16S rRNA gene sequencing and bacteria- and genus-specific quantitative PCR was used to profile microbial communities and their associated functions in water, live feed (microalgae, Artemia , and rotifer), and European sea bass and gilthead sea bream larvae from hatcheries in Greece and Italy. The transfer to larvae of genus containing potential pathogens of fish was more likely with Artemia and rotifer than with microalgae or water, irrespective of geographic location. The presence of potentially pathogenic bacteria (Vibrio and Pseudoalteromonas) in the core microbiota of water, live feed, and fish larvae, the enrichment of different bacterial resistance pathways and biofilm formation, and the overall low beneficial bacteria load during larval ontogeny emphasizes the risk for disease outbreaks. The present data characterizing microbiota in commercial aquaculture hatcheries provides a baseline for the design of strategies to manage disease and to model or remediate potential adverse environmental impacts. [Display omitted] • Microbiomes of gilthead sea bream and European sea bass in commercial hatcheries • Water, live feeds, age, and geography drive microbial diversity in hatcheries. • Host selection of beneficial bacteria occurs in early stages (start feeding). • Pathogenic bacteria are part of the core microbiota in commercial hatcheries. [ABSTRACT FROM AUTHOR]

The genus Arcobacter is a relatively poorly known group of bacteria, and the number of new species and sequences from non-culturable strains has increased considerably in recent years. This study investigates whether using media that contain NaCl might help to improve the recovery of Arcobacter spp. from marine environments. To this aim, 62 water and shellfish samples were analysed in parallel, with both a commonly used culture method (enrichment in Arcobacter -CAT broth followed by culture on Blood Agar) and a new one that supplements the Arcobacter -CAT enrichment broth with 2.5% NaCl (w/v) followed by culturing on Marine Agar. The new method yielded ca. 40% more positive samples and provided a higher diversity of known (11 vs. 7) and unknown (7 vs. 2) Arcobacter species. Among the 11 known species recovered, Arcobacter marinus and Arcobacter halophilus were isolated only by this new method. No more strains of these species have been isolated since their original descriptions, both of which were based only on a single strain. In view of that, the phenotypic characteristics of these species are re-evaluated in the present study, using the new strains. Strains of A. halophilus had the same phenotypic profile as the type strain. However, some strains of A. marinus differed from the type strain in that they did not hydrolyse indoxyl-acetate, becoming, therefore, the first Arcobacter species to show a varying ability to hydrolyse indoxyl-acetate. This study shows to what extent a simple variation to the culture media can have a big influence on positive samples and on the community of species recovered. [ABSTRACT FROM AUTHOR]

To characterize the degradation mechanisms of silicate glasses in river and marine aquatic environments, soda-lime silicate, potash-lime silicate and lead silicate glasses were submerged during 300 days in synthetic marine and river solutions. The alteration was characterized through optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDS) and atomic force microscopy (AFM). The results of this induced alteration showed that the degradation mechanism is directly connected to the chemical composition of glass. In soda-lime silicate glasses the degradation proceeds in a two-step mechanism: firstly hydration and fissure development occurs, and secondly fissures grow and pits are formed. Lead silicate glass forms simultaneously pits and a recurrent alteration layer. Potash-lime silicate glasses forms stratified gel layers, which are easily detached. The potash-lime silicate glass was the least durable under aquatic conditions. Samples submerged in simulated marine water were altered faster than those submitted to river water. [ABSTRACT FROM AUTHOR]

Experiments were carried out, the aim of which was to determine the leaching rates for bisphenol A (4,4'-(propane-2,2-diyl)diphenol - BPA), 4- tert -octylphenol (OP), 4-nonylphenol (NP) from polycarbonate and recycled tyre granules into the seawater. Additionally biodegradation, sorption on marine suspended particulate matter and sorption on various types of nano-TiO 2 of BPA, OP, NP were studied. Experiments were carried out on plastics at various stages of degradation. The conducted experiment confirmed the flux of BPA, OP and NP from the studied plastics into seawater. The initial photodegradation of the plastic had a significant influence on the amount of the studied components released into water. During the first days of the experiment leaching was weaker from aged materials. After 60 days leaching of BPA and OP was higher for aged plastic compared to unaged. On average, suspension adsorbed OP, BPA and NP from seawater at respective levels of 37%, 75% and 100%. On the other hand, during biodegradation on average 25%, 9% and 2% of OP, BPA and NP respectively are removed from water. Nano-TiO 2 of 21 nm pore size diameter adsorbed all the compounds more strongly than nano-TiO 2 of 15 nm pores sized coated with Al and stearic acid. The strongest sorption (100%) on different types of nano-TiO 2 was that of the most hydrophobic and more linear structured NP with just one phenol group. The weakest sorption was observed in the case of BPA, which is the least hydrophobic, and characterized by higher compared to NP and OP steric hindrance and electrostatic repulsion. [ABSTRACT FROM AUTHOR]

Laser ablation inductively coupled mass spectrometry (LA-ICPMS) was used to determine Sr and Ba profiles along the growth axis of otholiths of European smelt caught in the Wadden Sea, the IJsselmeer and the Markermeer and to investigate the migration behaviour of the fish between the freshwater lakes and the marine environment. The use of Sr and Ba otolith profiles and their dissolved concentrations in the three aquatic systems provided a robust method for habitat classification and migration behaviour of the 111 individual smelts. No evidence was found of the migration of individuals from the Wadden Sea to the Ijsselmeer due to no marine Sr/Ba signal in the Ijsselmeer smelt. The Ba and Sr concentrations in the otoliths of Wadden Sea smelt suggest a mixture of two populations: juveniles that were born in the Wadden Sea and species that were born in Lakes IJsselmeer or Markermeer and migrated to the Wadden Sea. In the IJsselmeer different types of otolith profiles were observed depending on the migration history of the individuals in that lake: some individuals have probably not moved a lot, others may have used tributaries (e.g. the river IJssel) as spawning grounds or migrated from Markermeer to Ijsselmeer. [ABSTRACT FROM AUTHOR]

Finfish mariculture is typically threatened by parasite and disease outbreaks. Therefore, it is important to identify parasite species of potential risk for this activity. Snappers are valuable food fish worldwide. In the Eastern Pacific, spotted rose snapper ( Lutjanus guttatus [Steindachner, 1869]) is a firm candidate for sea-cage aquaculture. In the current study, the parasitism of caged L. guttatus by dactylogyrids was evaluated for the first time during a complete farming period. Twenty five thousand juvenile fish produced at the Research Center for Food and Development (CIAD, Mazatlan Unit) were reared in a sentinel sea-cage from February to November 2012 in Mazatlan Bay, Mexico. A fish sample ( n = 15) was obtained every month. Dactylogyrids from the left second gill arch were identified and quantified. A total of 18,704 dactylogyrids distributed in three species, Euryhaliotrema perezponcei García-Vargas, Fajer-Ávila and Lamothe-Argumedo, 2008, E. mehen (Soler-Jiménez, García-Gasca and Fajer-Ávila, 2012), and Haliotrematoides guttati García-Vargas, Fajer-Ávila and Lamothe-Argumedo, 2008 (Monogenea: Dactylogyridae) was found, which were able to infect caged L. guttatus since the first month of the farming period. Prevalence of these parasite species was 100% all the time, except for initial low values for E. mehen and H. guttati . The mean intensity of infection of each dactylogyrid species varied significantly between sampling months. Euryhaliotrema perezponcei was the most abundant parasite, reaching the highest mean intensity in May, June and July (154.3, 296.9 and 176.6 parasites/host, respectively). No clear seasonality of infection was observed; however, the influence of the water temperature on the observed infection levels is discussed. There was no mortality, change on behavior or pathological signs. However, given the rapid infection and proliferation of dactylogyrids, particularly E. perezponcei on L. guttaus reared in a sentinel sea-cage, outbreak of these parasites could be expected when this fish species is cultured on a large scale. [ABSTRACT FROM AUTHOR]

Abstract: Use of fecal indicator bacteria (FIB) for monitoring beach water quality is based on their co-occurrence with human pathogens, a relationship that can be dramatically altered by fate and transport processes after leaving the human intestine. We conducted a prospective cohort study at Avalon Beach, California (USA), where the indicator relationship is potentially affected by the discharge of sewage-contaminated groundwater and by solar radiation levels at this shallow, relatively quiescent beach. The goals of this study were to determine: 1) if swimmers exposed to marine water were at higher risk of illness than non-swimmers; 2) if FIB measured in marine water were associated with swimmer illness, and; 3) if the associations between FIB and swimmer health were modified by either submarine groundwater discharge or solar radiation levels. There were 7317 individuals recruited during the summers of 2007–08, 6165 (84%) of whom completed follow-up within two weeks of the beach visit. A total of 703 water quality samples were collected across multiple sites and time periods during recruitment days and analyzed for FIB using both culture-based and molecular methods. Adjusted odds ratios (AOR) indicated that swimmers who swallowed water were more likely to experience Gastrointestinal Illness (GI Illness) within three days of their beach visit than non-swimmers, and that this risk was significantly elevated when either submarine groundwater discharge was high (AOR [95% CI]:2.18 [1.22–3.89]) or solar radiation was low (2.45 [1.25–4.79]). The risk of GI Illness was not significantly elevated for swimmers who swallowed water when groundwater discharge was low or solar radiation was high. Associations between GI Illness incidence and FIB levels (Enterococcus EPA Method 1600) among swimmers who swallowed water were not significant when we did not account for groundwater discharge, but were strongly associated when groundwater discharge was high (1.85 [1.06, 3.23]) compared to when it was low (0.77 [0.42, 1.42]; test of interaction: P = 0.03). These results demonstrate the need to account for local environmental conditions when monitoring for, and making decisions about, public health at recreational beaches. The views expressed in this article are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency. [Copyright &y& Elsevier]

Ammonia is an important nutrient in coastal and oceanic waters due to its role in the aquatic nitrogen cycle. However, the presence of the analyte at trace concentrations (nanomolar) and the high salinity of the water make its analysis a real challenge. Historically, flow-based methodologies, such as segmented flow analysis, and, more recently, flow-injection analysis and sequential injection analysis, have been used to assist with this difficult task. This review explains the importance of the analysis of ammonia in estuarine and marine water samples and the challenges facing the analytical chemist. We describe the flow-based methodologies that have been developed for this particular application. We discuss detection and on-line sample-pretreatment strategies employed to improve the limit of detection and to reduce and eliminate interferences, and illustrate them with examples of field applications. [ABSTRACT FROM AUTHOR]

Reports concerning the quantitative analysis of pharmaceuticals in marine ecosystems are somewhat limited. It is necessary to determine pharmaceutical fate and assess any potential risk of exposure to aquatic species and ultimately, seafood consumers. In the work presented herein, analytical methods were optimised and validated for the quantification of pharmaceutical residues in wastewater effluent, receiving marine waters and marine mussels (Mytilus spp.). Selected pharmaceuticals included two non-steroidal anti-inflammatory drugs (NSAIDs) (diclofenac and mefenamic acid), an antibiotic (trimethoprim), an antiepileptic (carbamazepine) and a lipid regulator (gemfibrozil). This paper also presents the results of an in situ study in which caged Mytilus spp. were deployed at three sites on the Irish coastline over a 1-year period. In water samples, pharmaceutical residues were determined using solid phase extraction (SPE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS). The extraction of pharmaceuticals from mussel tissues used an additional pressurised liquid extraction (PLE) step prior to SPE and LC–MS/MS. Limits of quantification between 15 and 225ng·L−1 were achieved in wastewater effluent, between 3 and 38ng·L−1 in marine surface water and between 4 and 29ng·g−1 dry weight in marine mussels. Method linearity was achieved for pharmaceuticals in each matrix with correlation coefficients of R2 ≥0.976. All five selected pharmaceuticals were quantified in wastewater effluent and marine surface waters. This work has demonstrated the susceptibility of the Mytilus spp. to pharmaceutical exposure following the detection of pharmaceutical residues in the tissues of this mussel species at measurable concentrations. [ABSTRACT FROM AUTHOR]

• Overview on oxidative treatment processes for different industrial applications. • Compilation of disinfection by-product types/concentrations in marine water uses. • Estimation of global DBP inputs into marine water from different industries. • Comparison of anthropogenic bromoform production to emissions from natural sources. Oxidative treatment of seawater in coastal and shipboard installations is applied to control biofouling and/or minimize the input of noxious or invasive species into the marine environment. This treatment allows a safe and efficient operation of industrial installations and helps to protect human health from infectious diseases and to maintain the biodiversity in the marine environment. On the downside, the application of chemical oxidants generates undesired organic compounds, so-called disinfection by-products (DBPs), which are discharged into the marine environment. This article provides an overview on sources and quantities of DBP inputs, which could serve as basis for hazard analysis for the marine environment, human health and the atmosphere. During oxidation of marine water, mainly brominated DBPs are generated with bromoform (CHBr 3) being the major DBP. CHBr 3 has been used as an indicator to compare inputs from different sources. Total global annual volumes of treated seawater inputs resulting from cooling processes of coastal power stations, from desalination plants and from ballast water treatment in ships are estimated to be 470–800 × 109 m3, 46 × 109 m3 and 3.5 × 109 m3, respectively. Overall, the total estimated anthropogenic bromoform production and discharge adds up to 13.5–21.8 × 106 kg/a (kg per year) with contributions of 11.8–20.1 × 106 kg/a from cooling water treatment, 0.89 × 106 kg/a from desalination and 0.86 × 106 kg/a from ballast water treatment. This equals approximately 2–6% of the natural bromoform emissions from marine water, which is estimated to be 385–870 × 106 kg/a. [Display omitted] [ABSTRACT FROM AUTHOR]

During a 12 month period (June 2007–May 2008), the prevalence and susceptibility of Salmonella serovars and their relation to specific pathogenic and indicator bacteria in river and coastal waters was investigated. A total of 240 water samples were collected from selected sites in Acheron and Kalamas Rivers and the Ionian Sea coast in north western Greece. The samples were analyzed for Salmonella spp., Listeria spp., Campylobacter spp., Escherichia coli O157, Staphylococci, Pseudomonas spp., Total Coliforms, Fecal Coliforms, Fecal Streptococci, Total Heterotrophic Flora at 20°C and at 37°C, fungi and protozoa (Cryptosporidium, Giardia). Susceptibility tests to nine antimicrobials (ampicillin, amikacin, amoxicillin/clavulavic acid, cefuroxime, ciprofloxacin, cefoxitin, tetracycline, ticarcillin/clavulanic acid, ampicillin/sulbactam) were performed using the disk diffusion method for Salmonella isolates. We isolated 28 serovars of Salmonella spp. identified as Salmonella enteritidis (23), Salmonella thompson (3) and Salmonella virchow (2). Multi-drug resistant Salmonella serovars were isolated from both river and marine waters, with 34.8% of S. enteritidis and 100% of S. virchow being resistant to more than 3 antibiotics. Also we isolated 42 strains of Listeria spp. identified as L. monocytogenes (20), L. innocua (9), L. seeligeri (2) and L. ivanovii (11). All the Listeria isolates were susceptible to the tested antibiotics. No Campylobacter spp., E. coli O157, Cryptosporidium and Giardia were detected. The overall ranges (and average counts) of the indicator bacteria were: Total Coliforms 0–4×104 cfu/100ml (3.7×103 cfu/100ml), Fecal Coliforms 0–9×103 cfu/100ml (9.2×102 cfu/100ml), Fecal Streptococci 0–3.5×104 cfu/100ml (1.4×103 cfu/100ml), Total Heterotrophic Flora at 20°C 0–6×103 cfu/ml (103 cfu/ml) and at 37°C 0–5×103 cfu/ml (4.9×102 cfu/ml). Weak or non significant positive Spearman correlations (p <0.05, r s range: 0.13–0.77) were obtained between Salmonella, Listeria, fungi and indicator bacteria. The results underline the complexity of the interrelations between pathogens and indicator bacteria, and the necessity to assess the presence of resistant bacteria in the aquatic environments. [ABSTRACT FROM AUTHOR]

Within the context of risk evaluation of chemical spillages into the marine environment, this paper reports on an offshore experiment to study the behaviour of styrene spilled into sea under natural conditions and discusses theoretical approaches. Floating structures were used to enclose the spillage and the gaseous cloud formation, and dissolution processes were in situ monitored. The identification of spill risks for man and marine environment through GESAMP’s hazard profile is described for styrene: Styrene is rated as a chemical with a significant health hazard that will float but also evaporate. However, monitoring of the water column in the experiments showed that the concentration of styrene in water during the first hour represents 50% of the product spilled. For the potentially exposed public, the GESAMP hazard rating recommends the closure of beaches and evacuation. The risk assessment developed from experimental data confirms this safety advice. [ABSTRACT FROM AUTHOR]

Abstract: A highly sensitive laboratory methodology for simultaneous determination of methylation and reduction of spiked inorganic mercury (Hg2+) in marine water labelled with high specific activity radiotracer (197Hg prepared from enriched 196Hg stable isotope) was developed. A conventional extraction protocol for methylmercury (CH3Hg+) was modified in order to significantly reduce the partitioning of interfering labelled Hg2+ into the final extract, thus allowing the detection of as little as 0.1% of the Hg2+ spike transformed to labelled CH3Hg+. The efficiency of the modified CH3Hg+ extraction procedure was assessed by radiolabelled CH3Hg+ spikes corresponding to concentrations of methylmercury between 0.05 and 4ngL−1. The recoveries were 73.0±6.0% and 77.5±3.9% for marine and MilliQ water, respectively. The reduction potential was assessed by purging and trapping the radiolabelled elemental Hg in a permanganate solution. The method allows detection of the reduction of as little as 0.001% of labelled Hg2+ spiked to natural waters. To our knowledge, the optimised methodology is among the most sensitive available to study the Hg methylation and reduction potential, therefore allowing experiments to be done at spikes close to natural levels (1–10ngL−1). [Copyright &y& Elsevier]

Abstract: Enterococci are used to assess the risk of negative human health impacts from recreational waters. Studies have shown sustained populations of enterococci within sediments of beaches but comprehensive surveys of multiple tidal zones on beaches in a regional area and their relationship to beach management decisions are limited. We sampled three tidal zones on eight South Florida beaches in Miami-Dade and Broward counties and found that enterococci were ubiquitous within South Florida beach sands although their levels varied greatly both among the beaches and between the supratidal, intertidal and subtidal zones. The supratidal sands consistently had significantly higher (p < 0.003) levels of enterococci (average 40 CFU/g dry sand) than the other two zones. Levels of enterococci within the subtidal sand correlated with the average level of enterococci in the water (CFU/100mL) for the season during which samples were collected (r s = 0.73). The average sand enterococci content over all the zones on each beach correlated with the average water enterococci levels of the year prior to sand samplings (r s = 0.64) as well as the average water enterococci levels for the month after sand samplings (r s = 0.54). Results indicate a connection between levels of enterococci in beach water and sands throughout South Florida’s beaches and suggest that the sands are one of the predominant reservoirs of enterococci impacting beach water quality. As a result, beaches with lower levels of enterococci in the sand had fewer exceedences relative to beaches with higher levels of sand enterococci. More research should focus on evaluating beach sand quality as a means to predict and regulate marine recreational water quality. [Copyright &y& Elsevier]

Abstract: Density, species composition and antimicrobial resistance in bacteria of the Enterococcus genus were evaluated in seawater and sands from 2 marine recreational beaches with different levels of pollution. The 2 beaches showed predominance of Enterococcus faecalis and Enterococcus faecium, in the water and the sand. Dry sand presented higher densities of Enterococcus sp. and higher frequency of resistant strains than wet sand and seawater. The beach with a higher degree of pollution presented higher percentages of resistant strains (66.7% and 61.5%, in sand and in water, respectively) and resistance to a larger number of antimicrobials compared with the less polluted beach, Ilha Porchat (35.7% and 31.25% of resistant strains in sand and water, respectively). In water samples, the highest frequencies of resistance were obtained against streptomycin (38.5%) and erythromycin (25%), whilst in sand, the highest frequencies were observed in relation to erythromycin and tetracycline (38.1% and 14.3%, respectively). These results show that water and sands from beaches with high indexes of faecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance. [Copyright &y& Elsevier]

Abstract: The toxicity of stormwater runoff during various time-based stages was measured in both grab and composite samples collected from three highly urbanized highway sites in Los Angeles, California between 2002 and 2005. Stormwater runoff samples were tested for toxicity using three freshwater species (the water flea Ceriodaphnia dubia, the fathead minnow Pimephales promelas, and the green algae Pseudokirchneriella subcapitatum) and two marine species (the purple sea urchin Strongylocentrotus purpuratus, and the luminescent bacteria Photobacterium phosphoreum using Microtox™). Toxicity results varied substantially throughout the storm events for both freshwater and marine species toxicity tests. In general, however, the first few samples were found to be more toxic compared with those collected during later stages of each storm event. In most cases, more than 40% of the toxicity was associated with the first 20% of discharged runoff volume. Furthermore, on average, 90% of the toxicity was observed during the first 30% of storm duration. Toxicity identification evaluation results found copper and zinc to be the primary cause of toxicity in about 90% of the samples evaluated with these procedures. Surfactants were also found to be the cause of toxicity in less than 10% of the samples. [Copyright &y& Elsevier]

Abstract: A total of 3086 samples, both marine (2916) and freshwater creeks/outfall samples (170) were collected and analyzed for enterococci during October 2002–April 2005, from 52 designated beaches in Oregon. A total of 3.2% (99/3086) of the samples at 21 beaches exceeded 158 most probable number (MPN)/100 milliliters (mL). The average enterococci levels of these 99 exceedances was 559MPN/100mL, with a maximum of 4352MPN/100mL (Otter Rock and Ona) and a minimum of 160MPN/100mL (Sunset Bay State Park, Bastendorff, and Mill). For marine water, 77/2916 (2.6%) exceeded 158MPN/100mL. For freshwater, 22/170 (12.9%) exceeded 158MPN/100mL, with a maximum of 587MPN/100mL at Sunset Bay. Sixty percent of the marine and 9% of freshwater exceedances occurred during the winter. Seventy-two percent (55/77) of the marine exceedances occurred after rainfall events (0.01–60.0mm). At Harris and Mill Beaches, cumulative rainfall was highly correlated with bacterial densities, R =0.7. Rainfall, at both beaches, explained about one-half the variation in log10 bacteria density (R 2 =0.5). Additional monitoring is warranted to further characterize bacterial contamination in Oregon waters. [Copyright &y& Elsevier]

Abstract: In recent past, Mumbai Municipal corporation was not able to keep pace with required infrastructural facilities due to unprecedented population growth. Sewage disposal is one of the major issues, which needed immediate attention because huge quantity of sewage with only preliminary treatment is disposed into the nearby coastal areas and has deteriorated the water quality of the near coastal region. World Bank assisted Bombay Sewage Disposal Project (BSDP) undertaken by the Municipal Corporation of Bruhan Mumbai (MCBM) envisaged sewage discharges through marine outfalls at Worli and Bandra and treatment by aerated lagoons for other areas before disposal in creeks. During BSDP programme, studies were undertaken on water quality assessment along the west coast of Mumbai before and after commissioning of the Worli outfall. A pre- and post-commissioning water quality database for selected parameters was generated for near shore as well as west coast region up to 5 km seaward distance to assess the efficacy of the Worli outfall and delineate the areas affected around diffuser location of the outfall due to sewage disposal. This paper presents observations of the coastal studies at Mumbai and the impact zone of Worli outfall. [Copyright &y& Elsevier]

Numerical simulations were carried out to determine the particle size distribution (PSD) in marine waters by accounting for particle influx, coagulation, sedimentation and breakage. Instead of the conventional rectilinear model and Euclidean geometry, a curvilinear collision model and fractal scaling mathematics were used in the models. A steady-state PSD can be achieved after a period of simulation regardless of the initial conditions. The cumulative PSD in the steady state follows a power-law function, which has three linear regions after log–log transformation, with different slopes corresponding to the three collision mechanisms, Brownian motion, fluid shear and differential sedimentation. The PSD slope varies from −3.5 to −1.2 as a function of the size range and the fractal dimension of the particles concerned. The environmental conditions do not significantly alter the PSD slope, although they may change the position of the PSD and related particle concentrations. The simulation demonstrates a generality in the shape of the steady-state PSD in the ocean, which is in agreement with many field observations. Breakage does not affect the size distribution of small particles, while a strong shear may cause a notable change in the PSD for larger and fractal particles only. The simplified approach of previous works using dimensional analysis still offers valuable approximations for the PSD slopes, although the previous solutions do not always agree with the simulation results. The variation in the PSD slope observed in field investigations can be reproduced numerically. It is argued that non-steady-state conditions in natural waters could be the main reason for the deviation of PSD slopes. A change in the nature of the particles, such as stickiness, and environmental variables, such as particle input and shear intensity, could force the PSD to shift from one steady state to another. During such a transition, the PSD slope may vary to some extent with the particle population dynamics. [Copyright &y& Elsevier]

Seasonal dynamics of motile Aeromonas in a treated urban effluent and in natural seawater along the Sfax coast (Mediterranean sea, Tunisia) were measured over a year concurrently with seven environmental factors, and compared with those of faecal coliforms. Counts for Aeromonas from a standard plate count method, ranged from 1.48×105 CFU.100 ml−1 to 2.2×108 CFU.100 ml−1 in the effluent and from 7.9×103 CFU.100 ml−1 to undetectable level in the surface marine waters. Contrary to faecal coliforms, the Aeromonas dynamics exhibited a seasonal distribution in seawater which was inverse of the seasonal distribution in the sewage: From the end of November 1998 to April 1999 (cold period), Aeromonas counts increased in the treated effluent, while it decreased very rapidly in seawater. From May to October (warm period), Aeromonas abundance decreased in the effluent but showed an increasing fluctuating trend in the marine waters with a maximum in late summer/early autumn when the temperatures were around 22–23°C. Multiple correlation and regression analyses suggest, by the coefficient of determination (R2), that 42% of variance in Aeromonas number changes in the treated effluent, may be explained by only turbidity, radiation and Aeromonas density in the previous sample, while 37% of variance in marine ecosystem were explained by radiance and conductivity. Furthermore, the t statistics and their p values and the coefficient of partial determination (r2) indicated that radiance contributed the most (r2=0.3184, t=−3.2, p=0.0041) to the dynamics of motile Aeromonas in seawater, when combined with conductivity.The models relevant for changes in faecal coliforms abundance incorporated turbidity, radiance in the effluent and conductivity, pH, radiance, turbidity in coastal marine environment. These models explain 66% and 73% of the observed cell number fluctuation, with turbidity (r2=0.529, t=5.08, p=0.0001) and conductivity (r2=0.5407, t=4.97, p=0.0001) as dominant factors in the multivariate model proposed, respectively, for the two sampling sites. The results presented here suggest that the combination of negative effects of sunlight and conductivity in natural seawater mainly affects the colony-forming capacity and make the motile Aeromonas nonrecoverable during cold months. [Copyright &y& Elsevier]

The human norovirus (HNoV), on a global scale, is the prevailing cause of contagious viral gastroenteritis outbreaks, with more than 200 000 deaths annually. This study aimed at assessing specific prevalence of HNoV pollution in different water sources and their roles in the dissemination of HNoV, with a view to refocus water sources and sewage management options for policy making towards public health safety. In this regard, we conducted a systematic review and meta-analysis (SR/MA) of the prevalence of HNoV in water sources. We searched PubMed, Google Scholar, Scopus and Web of Science for studies on HNoV prevalence in water sources without temporal restriction, till January 30, 2021. We conducted a random-effects meta-analysis of the HNoV prevalence and stratified the study by water type, continent, gross national income (GNI) group and genogroup. Further, a mixed-effects meta-regression model was performed for sensitivity analysis. The literature search identified 61 studies on water source-based HNoV (WsHNoV) prevalence. The pooled WsHNoV prevalence was 31.7% (95%CI: 25.1–38.5) but varied according to water sources types; river water showing the highest estimate at 43.5% (95%CI: 33.9–53.4), followed by estuarine water (30.6%, 95%CI: 12.5–52.2), composite water (27.9%, 95%CI: 13.5–44.9), marine water (25.9%, 95%CI: 10.0–45.6), groundwater (19.7%, 95%CI: 9.4–32.3) and lake water (2.2%, 95%CI: 0–25.8). Further, the findings indicated the highest WsHNoV prevalence in Africa as 55.9% (95% CI: 28.2–81.9), followed by Asia (31.6%, 95% CI: 22.3–41.6), Europe (29.8%, 95% CI: 17.9–43.2), North America (27.7%, 95% CI: 11.2–47.6) and South America (27.1%, 95%CI: 0.09–49.4). The WsHNoV prevalence stratified by GNI group was 40.6% (95%CI: 27.9–53.9) in middle-income countries and 28.7% (95%CI: 21.7–36.1) in high-income countries respectively. The prevalence of GI, GII and GI & GII genogroup in natural water was 16.4% (95%CI: 12.0–21.3), 20.6% (95%CI: 15.7–25.8) and 12.8% (95%CI: 6.9–20.6) respectively. Evidently, prevalence of the HNoV genogroup in water sources mirrors the pattern of HNoV gastroenteritis and GII genogroup dominance worldwide. In conclusion, public health efforts against waterborne diseases should prioritize water resource/sewage management options and policies towards ardent water sources pollution prevention. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wax-modified paper as a platform for executing in-situ droplet colorimetric assay. • Demonstrated sensitive determination of Fe3+ in environmental water samples. • Excellent LOD (0.01 ppm) and LDR (0.1–100 ppm) was achieved. • LOD improved by 3-order of magnitude as compared to unmodified paper. The present study is focused on developing a colorimetric spot assay for direct determination of Fe3+ in water. The established method was based upon the use of wax modified paper as a low-cost platform onto which a droplet-based colorimetric reaction between aqueous Fe3+ and 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol (5-Br-PADAP) was executed. The wax-modified paper was characterized by goniometry that clearly showed a substantial increase in the water contact angle (θ) from 0° to ~123°. Morphological differences in the cellulose fibers of unmodified and modified paper were further confirmed via SEM and AFM analysis. The proposed assay was simple to execute and the resulting color change was readable via naked eyes with total assay time not exceedingly more than 10 min. The limit of detection and linear dynamic range for Fe3+ assay executed on the wax-modified paper were 0.01 ppm and 0.1–100 ppm, respectively. The attractive features of the established assay mainly include its simplicity, fast response time, inexpensive modification/platform, low reagent/analyte volume requirement and instrument-free readout. Hence, the proposed paper-based chemosensor can serve as a promising tool for point-of-use application in resource limiting regions especially dealing with iron contamination. [ABSTRACT FROM AUTHOR]

• The probe NPH was rational configured on the receptor1-fluorescence-receptor2 model, which showed fluorescence "turn on" simultaneous sensing of Al3+, Mg2+ and Zn2+ and further fluorescence colorimetric detection of EDTA. • A new sensing mechanism was proposed, which the presence of Al3+, Mg2+ and Zn2+ caused the different degree deprotonation processes and was confirmed by 1H NMR, FT-IR and DFT calculation. • Probe NPH was applied in living cells (Hela and HepG) and construction of molecular logic gate. A multi-responsive fluorescence probe NPH was rational configured on the receptor 1 -fluorophore-receptor 2 model to discriminatively detect Al3+, Mg2+ and Zn2+. The probe NPH contained benzooxazole moiety (receptor 1) and 2-aldimine-phenol unit (receptor 2), which showed fluorescence "turn on" response for Al3+, Mg2+ and Zn2+ in DMF/H 2 O (9/1, V/V, pH = 7.4) medium and sensing mechanism was studied by 1H NMR, FT-IR and further confirmed by DFT calculation. The presence Mg2+ inhibited ESIPT and C = N isomerization processes, but the presence Al3+ caused a moderate deprotonation of the naphtholic OH. Finally, the presence of Zn2+ completely deprotonated the naphtholic OH and phenolic OH. The presence of Al3+, Mg2+ and Zn2+ resulted in the different degree deprotonation processes, which resulted the fluorescence responses at different emission wavelength. Interestingly, after addition of EDTA to the NPH /Al3+ complex, caused a new and strong emission peak at 560 nm along with a remarkable color change from yellow-green to yellow-orange, and the value of fluorescence intensity at 560 nm was linearly proportional to the concentration of EDTA. The NPH/ Al3+ complex could serve as a fluorescence colorimetric probe for the detection EDTA. In addition, probe NPH was applied in real water samples and construction of molecular logic gate. Importantly, fluorescence image experiments of Al3+, Mg2+, Zn2+ and EDTA in living HeLa cells and HepG cells confirmed its value in biological system. [ABSTRACT FROM AUTHOR]

• First risk assessment based only on measured concentrations in marine waters. • A probabilistic approach was used to account for variability and uncertainty. • No immediate risk can be expected given the available data. Microplastics are ubiquitous in the environment and given the large number of published hazard and exposure studies, quantitative environmental risks assessments of microplastics become feasible. We present here the first environmental risk assessment for marine waters based only on measured concentrations. The Thevariability and uncertainty of the measured data was accounted for in the exposure assessment, while probabilistic species sensitivity distributions were used for hazard assessment, from which a probability distribution was extracted for the predicted no-effect concentration (PNEC). By dividing the exposure distribution by the PNEC-distribution, we were able to calculate probabilistic risk characterisation ratios for each water body in which measurements were performed. Results show a good coverage of the world's major water bodies by measured exposure concentrations (MECs), while the hazard assessment could be improved by aligning the type of particles tested in hazard studies (size, form, polymer) to those actually found in the oceans. Overall, the mean predicted no-effect concentration (PNEC) is 3.84·106 part m−3, with Oryzias melastigma being the most sensitive species (calculated mean NOEC of 3.90·106 part m−3). Interestingly, the only type of dose descriptor that could be extracted from the literature for particles above 10−20 μm was the highest observed no effect concentration (HONEC), which indicates a very low or null toxicity of these larger MPs towards marine organisms. The mean MEC is 1.5·103 part m−3, the highest concentrations being measured in the Atlantic and Pacific Ocean. Although there is a very small overlap of the probability distribution associated with the RCR (0.00002 % of the data points), the mean RCR is 4·10-4 and therefore risks are unlikely given the available data. However, as increasing amounts of plastic reach the environment, RCRs can be expected to increase in the future. [ABSTRACT FROM AUTHOR]

• Seawater (SW0) can be used as a culture medium of Spirulina. • SW0 condition resulted in the highest carbohydrates productivity in Spirulina. • SW0 is an innovative cultivation strategy with the potential for Spirulina growth. This study aimed to evaluate the growth and production of biomolecules by Spirulina sp. LEB 18 cultivated in seawater. The seawater was used without nutrient addition (SW0) and supplemented with 100% (SW100), 50% (SW50), and 25% (SW25) nitrogen, phosphorus, iron, and EDTA concentrations that make up the Zarrouk culture medium. When grown in SW0, Spirulina sp. LEB 18 showed maximum biomass concentration (2.17 g L−1) on the 11th d of cultivation and an increase in the carbohydrate content and productivity by 203% and 52%, respectively, when compared to the control culture. This cultivation strategy demonstrated the feasibility of using seawater as an alternative to freshwater in cultures as well as reduced nutritional requirements for biomass and carbohydrate production. [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) are worldwide considered as emerging contaminants of large interest, and a primary threat to human health. It is becoming clear that the environment plays a central role in the transmission, spread, and evolution of antibiotic resistance. Although marine systems have been largely investigated, only a few studies have considered the presence of ARGs in meso- and bathypelagic waters. To date, no molecular based studies have yet been made to investigate the occurrence of ARGs in the Black Sea, the largest meromictic basin in the world, receiving water from a number of important European rivers and their residues of anthropogenic activities in permanently stratified mesopelagic water masses. In this study, we determined the presence and the abundance of five ARGs (bla CTXM , erm B, qnr S, sul 2, tet A) and of the heavy metal resistance gene (HMRG) czc A, in different sampling sites in the eastern and western Black Sea, at several depths (up to 1000 m) and various distances from the shoreline. Three ARGs (bla CTXM , sul 2, and tet A) and czc A were present in at least 43% of the analysed samples, whereas erm B and qnr S were never detected. In particular, sul 2 abundances increased significantly in coastal location, whereas tet A increased with sampling depth. These findings point out the Black Sea as a source of ARGs and HMRGs distributed along the whole water column. Unlabelled Image • The Black Sea is a source of resistance genes. • The antibiotic resistance genes sul 2 and tet A showed contrasting spatial dynamics. • No correlation between antibiotic and heavy metal resistance genes was found. [ABSTRACT FROM AUTHOR]

In this work, samples were collected from the Argentinean continental shelf –including a Marine Protected Area (MPA) - to assess the occurrence and distribution of synthetic microfibers (MFs), a widespread type of microplastic. MFs were present at 100% of the samples showing an average concentration of 182.85 ± 115.14 particles per Kg of dry sediment and 0.14 ± 0.08 items per m3 of marine water. MFs less than 1 mm were the most abundant (56.4% and 63%, for sediment and surface seawater respectively), followed by 1–2 mm and then 2–3 mm. In regards to the colour, both sediments and water had the major percentage of black MFs (25.6% and 28%, respectively) and the lowest one of green MFs (2.5% and 3%, respectively). Finally, MFs content in sediments was inversely correlated with depth (r = -0.93, p < 0.05). These findings provide the first evidence of microplastic contamination at the Argentinean continental shelf. • MFs were present in all samples, both sediment and surface seawater. • MFs concentration in seabed sediment ranged from 40 to 360 items per Kg of dry sediment. • MFs concentration in surface seawater ranged from 0.023 to 0.24 items/m3. • MFs concentration in sediment was inversely correlated with the depth. [ABSTRACT FROM AUTHOR]

Three methods for detecting E. coli in marine waters with the Multiple Tube Dilution method with MUG supplement: (1) Lauryl Tryptone Broth (LTB) at 35 deg. C then EC-MUG broth at 44.5 deg. C; (2) LTB-MUG broth at 35 deg. C then EC broth at 44.5 deg. C; (3) EC-MUG broth at 35deg. C then EC broth at 44.5 deg. C, incubated to 48 h, were compared. E. coli was confirmed using Eosin Methylene Blue agar and IMViC reactions or API20E. Method (1) detected more E. coli positive tubes (158) than methods (2) (135) or (3) (142). Six of the 158 tubes were fluorescent negative but E. coli positive (3.8% false negative) and eight were fluorescent positive but E. coli negative (5.1% false positive). Incubation for 24 h gave 5.7% false negatives and 3.8% false positives, whereas incubation for 48 h gave 3.8% false negatives and 5.1%false positives. In (1) gas production gave 24.7% false positives and 13.3% false negatives. Of 131 E. coli isolates retested for gas production and MUG reaction, the MUG reaction was best in EC-MUG at 35 deg. C (5.3% weak fluorescence) and worst in LTB-MUG (23.7% weak fluorescence). For E. coli in marine waters the MUG reaction without confirmation gave satisfactory results, and gas production had no value intheir presumptive detection. [ABSTRACT FROM AUTHOR]