RESUMEN

This research investigated the in-situ decay rates of four human wastewater-associated markers (Bacteroides HF183 (HF183), Lachnospiraceae Lachno3 (Lachno3), cross-assembling phage (crAssphage), pepper mild mottle virus (PMMoV) and three enteric viruses (human adenovirus 40/41 (HAdV 40/41), enterovirus (EV) and human norovirus GII (HNoV GII) in two estuarine water environments (Davidson Park (DP) and Hen and Chicken Bay (HCB) in temperate Sydney, NSW, Australia, employing qPCR and RT-qPCR assays. The study also aimed to compare decay rates observed in mesocosms with previously published laboratory microcosms, providing insights into the persistence of markers and viruses in estuarine environments. Results indicated varying decay rates between DP and HCB mesocosms, with HF183 exhibiting relatively faster decay rates compared to other markers and enteric viruses in sunlight and dark mesocosms. In DP mesocosms, HF183 decayed the fastest, contrasting with PMMoV, which exhibited the slowest. Sunlight induced higher decay rates for all markers and viruses in DP mesocosms. In HCB sunlight mesocosms, HF183 nucleic acid decayed most rapidly compared to other markers and enteric viruses. In dark mesocosms, crAssphage showed the fastest decay, while PMMoV decayed at the slowest rate in both sunlight and dark mesocosms. Comparisons with laboratory microcosms revealed faster decay of markers and enteric viruses in laboratory microcosms than the mesocosms, except for crAssphage and HAdV 40/41 in dark, and PMMoV in sunlight mesocosms. The study concludes that decay rates of markers and enteric viruses vary between estuarine mesocosms, emphasizing the impact of sunlight exposure, which was potentially influenced by the elevated turbidity at HCB estuarine waters. The generated decay rates contribute valuable insights for establishing site-specific risk-based thresholds of human wastewater-associated markers.

Asunto(s)

RESUMEN

While progress has been made in surveying the oceans to understand microbial and viral communities, the coastal ocean and, specifically, estuarine waters, where the effects of anthropogenic activity are greatest, remain partially understudied. The coastal waters of Northern Patagonia are of interest since this region experiences high-density salmon farming as well as other disturbances such as maritime transport of humans and cargo. Here, we hypothesized that viral and microbial communities from the Comau Fjord would be distinct from those collected in global surveys yet would have the distinctive features of microbes from coastal and temperate regions. We further hypothesized that microbial communities will be functionally enriched in antibiotic resistance genes (ARGs) in general and in those related to salmon farming in particular. Here, the analysis of metagenomes and viromes obtained for three surface water sites showed that the structure of the microbial communities was distinct in comparison to global surveys such as the Tara Ocean, though their composition converges with that of cosmopolitan marine microbes belonging to Proteobacteria, Bacteroidetes, and Actinobacteria. Similarly, viral communities were also divergent in structure and composition but matched known viral members from North America and the southern oceans. Microbial communities were functionally enriched in ARGs dominated by beta-lactams and tetracyclines, bacitracin, and the group macrolide-lincosamide-streptogramin (MLS) but were not different from other communities from the South Atlantic, South Pacific, and Southern Oceans. Similarly, viral communities were characterized by exhibiting protein clusters similar to those described globally (Tara Oceans Virome); however, Comau Fjord viromes displayed up to 50% uniqueness in their protein content. Altogether, our results indicate that microbial and viral communities from the Comau Fjord are a reservoir of untapped diversity and that, given the increasing anthropogenic impacts in the region, they warrant further study, specifically regarding resilience and resistance against antimicrobials and hydrocarbons.

RESUMEN

Estuaries have long been preferred sites of human settlement due to the benefits regarding proximity to fresh water and the ocean. As such, these environments have been subject to increasing anthropogenic pressures, resulting in issues of pollution and contamination. However, since the second half of the 20th century an environmental concern has reflected in the development of legislation, monitoring programmes and measures to diminish and control those impacts. The study presented herein integrates metals and metalloid concentrations from surface water samples obtained in a long-term monitoring programme (1986-2020) conducted in the Sado Estuary. The results obtained show a decrease and stabilisation of the concentrations of elements (between 81 % for Pb and 11 % for As in the average concentrations, between 83 % for Pb and 11 % for Cd in the median concentrations, and an increase of 1 % in the As median values). Nevertheless, high concentrations were still observed in the stations closest to the industrial area and the main freshwater to confluence with the estuary. Despite the efforts in improving the environmental quality of the Sado Estuary, possible effects in native species such as cuttlefishes and oysters are still a possibility, particularly in the stations where higher concentrations were registered, as well as close to nurseries as a result of trace metal transport through currents and tides.

Asunto(s)

RESUMEN

Previous studies conducted in other countries showed that neonicotinoid insecticides contaminated environmental waters and reduced aquatic invertebrate abundance. This study analysed neonicotinoid concentrations in estuarine waters of Indramayu Regency, Indonesia, and their potential toxicity to the aquatic environment. Data collection included water sampling and analysis, watershed and paddy field analyses, and literature review. The results showed that the detection frequency of neonicotinoids was 75%, with imidacloprid and thiamethoxam having the highest mean concentrations compared to other compounds. The sample collected in August 2021 from an estuary in the Patrol sub-district contained the highest total neonicotinoid concentration (140.26 ng/L). Five samples (31.25%) contained imidacloprid concentrations that exceeded the chronic benchmark regulated by the Netherlands, thus related regulation and policies are encouraged to be established in Indonesia to prevent potential harmful effect of neonicotinoids to the aquatic environment. There was no significant correlation between the neonicotinoid concentrations and the paddy field and watershed sizes as well as the land use proportion for paddy fields within the watershed. This study is the first to report neonicotinoid contamination in Indonesian estuarine waters.

RESUMEN

Photodegradation is a major elimination route of many pharmaceutically active compounds (PhACs) in natural surface waters, yet their photolytic behavior in estuarine waters with salinity gradient change is largely unknown. Herein, sulfamethazine and carbamazepine were taken as representative PhACs to explore the photolytic kinetic differences in Qinzhou Bay estuarine water samples collected from upper to lower reaches. Rapid photodegradation of sulfamethazine was found in lower estuarine water relative to upstream estuarine water; whereas for carbamazepine, photolytic rate was inversely proportional to the salinity of estuarine waters. Experiments with extracted estuarine dissolved organic matter (E-DOM) imply that the multivariate effects of triplet-excited E-DOM (3E-DOM∗) and halide ions are responsible for the enhancement photolysis of sulfamethazine. Radical scavenging experiments suggest that the photolysis enhancement can be ascribed to the contribution of reactive halogen species (RHS), while their contribution to carbamazepine is negligible and 3E-DOM∗ is the dominant reactive species for its photodegradation. This indicates that the reactivity differences with RHS and 3DOM∗ affect the photolytic kinetics of PhACs from upper estuarine waters to lower reaches, which is also supported by a good linear relationship between the ratios of photolytic rates for ten PhACs in E-DOM solution with/without halides and the ratios of the reactivity of these pollutants with RHS and 3DOM∗. These findings show that the different reactivity of PhACs with 3E-DOM∗ and RHS influences the photolytic kinetics in estuarine waters with different salinity, and highlights the photochemical behavior of organic micropollutants from upstream to downstream estuarine waters.

Asunto(s)

RESUMEN

To assess the contamination by polycyclic aromatic hydrocarbons (PAHs) in organisms in the estuary of Changhua River in Hainan, we determined the content of 16 priority PAHs by gas chromatography and mass spectrometry (GC-MS). The composition, source, and potential edible risk of PAHs were studied. The results showed that the total PAHs of demersal fish (wet weight, same below), crustaceans, and pelagic fish were 5.52-787.98, 12.18-154.64, and 10.20-199.79 ng·g-1, respectively, and the average contents were 83.21, 64.72, and 89.48 ng·g-1, respectively. There were some differences in the content of PAHs in various organisms. The average content followed the order of pelagic fish > demersal fish > crustaceans. Compared with other areas in the country and abroad, the content of marine organisms'PAHs in the estuary of the Changhua River was above the medium level. The result of isomer characteristic ratio showed that the PAHs of 33 organisms mainly came from the combustion sources (petroleum combustion and biomass combustion) and petroleum sources. Moreover, demersal fish were greatly affected by combustion sources, while pelagic fish were greatly affected by petroleum sources. Human risk assessment indicated that the content of benzopyrene (BaP) was within the limits set by the European Union. Most of the organisms in the estuary of Changhua River were within the safe range of consumption, but the long-term consumption of these seafoods may pose a potential health risk (1.0×10-5≤ILCR<1.0×10-4).

Asunto(s)

RESUMEN

Although photochemical transformation is a major degradation pathway for antibiotics in surface freshwaters, the photodegradation of antibiotics from freshwaters downstream into seawater is largely unknown. Herein, sulfadiazine was adopted as a representative antibiotic to probe the alteration of photolytic kinetics along freshwater to seawater sampled from Qinzhou Bay, China. The results showed that the photodegradation rate constants of sulfadiazine significantly increased in estuarine waters along freshwaters to seawaters. Experiments in synthetic water samples with isolated local dissolved organic matter (IL-DOM) indicated that the increased photodegradation of sulfadiazine is attributed to the integrative effect of both IL-DOM and halide ions. Radical quenching experiments with tert-butanol (quenching of ·OH) and isopropanol (quenching of both ·OH and reactive halogen species, RHS) demonstrated that RHS are largely responsible for the halide-specific enhancement in the photodegradation of sulfadiazine, rather than other reactive species, such as triplet-excited IL-DOM and ·OH. However, triplet-excited IL-DOM was involved in the production of RHS by the oxidation of halide ions by the triplet-excited states. Experiments conducted with DOM analogues verified DOM-sensitized RHS formation, and the degradation induced by RHS is positively correlated with the triplet-excited reduction potentials of DOM analogues. These findings are helpful in deeply understanding the transformation of antibiotics, and demonstrate the importance of RHS-induced degradation in antibiotics fate models in estuarine water systems.

Asunto(s)

RESUMEN

One of the most used protocols to extract and quantify MPs is NOAA protocol in aquatic environments. However, there is still no standardized method to extract and quantify MPs in estuarine waters. The aim of this work was to adapt the NOAA protocol to quantify microplastics in estuarine water and provide all the details and changes to improve the efficiency of the method. For that, four types of plastic (PE-LD; PET; PA; PE-HD) were used in artificial samples to test all the steps of the protocol. Several criteria were tested, namely: (i) quantities of H2O2 used for organic matter degradation; (ii) temperatures of drying samples; and (iii) density separation efficacy. With the proposed modifications, the microplastics extraction were above 90%, regardless the type of plastic, with PE-LD reaching 100% of efficiency. The new adapted protocol that we propose will allow a better efficiency in extraction and quantification of microplastics in samples from estuarine environments. •Four different types of plastic (PE-LD; PET; PA; PE-HD) were used to test the efficiency of the protocol•Details as the ideal quantity of H2O2, temperature and exact quantity of NaCl were tested and defined during the experiments•Efficiency of the microplastics extraction were above 90.

RESUMEN

This study focuses on the fate of pharmaceuticals discharged into an estuarine environment, particularly into the Turbidity Maximum Zone (TMZ). Batch experiments were set up to investigate the factors regulating the degradation of 53 selected pharmaceuticals. Treated effluents from Bordeaux city (France) were mixed with water from the estuarine Garonne River during 4weeks under 6 characterized conditions in order to assess the influence of suspended particulates, sterilization, untreated wastewater input and dilution on the degradation kinetics. Of the 53 pharmaceuticals monitored, 43 were quantified at the initial time. Only 7 exhibited a persistent behavior (e.g. carbamazepine, meprobamate) while biotic degradation was shown to be the main attenuation process for 38 molecules (e.g. abacavir, ibuprofen highly degradable). Degradation was significantly enhanced by increasing concentrations of suspended solids. A persistence index based on the half-lives of the compounds has been calculated for each of the 43 pharmaceuticals to provide a practical estimate of their relative stability. The stability of pharmaceuticals in estuarine environments is likely to be highly variable and attenuated primarily by changes in suspended solid concentration.

RESUMEN

A low-cost methodology using hollow fiber liquid-phase microextraction (HF-LPME) and capillary zone electrophoresis (CZE) with UV-Vis detector was developed to analyze the salicylic acid (SA) in estuarine and riverine waters. The technique is easy-to-use and rapid, and demands little volume of organic solvent. The extraction was carried out using a polypropylene membrane supporting into octan-1-ol. HF-LPME under optimized conditions (donor solution sample pH 2, acceptor solution pH 14, sample volume 25 mL, fiber length 10 cm, acceptor volume 25 µL, extraction time 3 h and stirring speed 350 rpm) presented high enrichment factor (407 times) and good recovery in real water samples (from 88 to 110%). A limit of detection of 2.6 µg L-1 was achieved using CZE with UV-Vis detector as quantification method. The method was applied to direct quantification of SA in environmental complex estuarine and riverine water matrices.

Asunto(s)

RESUMEN

This study reports the occurrence and the effect of the environmental factors on the spatial and temporal distribution of the dinoflagellate Akashiwo sanguinea (Hirasaka) Hansen & Moestrup in estuarine waters of northeastern Brazil. Samples were collected at seven stations from March 2007 to February 2008 during high tide and low tide, using Van Dorn bottles. The samples were immediately fixed with Lugol and analyzed with the Utermöhl method. Water samples were also collected for the identification of the hydrological characteristics of the area. Akashiwo sanguinea occurred throughout the annual cycle and at all sampling sites with densities ranging between 5 and 410 x 103 cells.L–1. The highest densities were recorded at low tide, especially during the months of the rainy season (July: 210 x 103 cells.L–1; August: 410 x 103 cells.L–1). Density values were within the normal range and blooms were not detected. Despite being common in the area, the species showed preference for sites with high concentrations of orthophosphate and total dissolved phosphorus and with salinity in the mesohaline regime.

Este estudo relata a ocorrência e o efeito dos fatores ambientais na distribuição espacial e temporal do dinoflagelado Akashiwo sanguinea (Hirasaka) Hansen et Moestrup em águas estuarinas do Nordeste do Brasil. As amostras foram coletadas em sete estações, durante o período de março 2007 a fevereiro 2008 durante os regimes de preamar e baixa-mar, com o auxílio de garrafas tipo Van Dorn. As amostras foram imediatamente fixadas com lugol e analisadas pelo método de Utermöhl. Amostras de água foram também coletadas para a identificação das características hidrológicas da área. Akashiwo sanguinea ocorreu em todo o ciclo anual e em todos os locais de coleta com densidade variando de 5 a 410 cells.L–1 x 103, sendo as maiores densidades registradas na baixa-mar, principalmente, durante os meses do período chuvoso (julho 210 cells.L–1 x 103, agosto 410 cells.L–1 x 103). Os valores quantitativos estiveram dentro dos padrões normais, não tendo sido detectados florescimentos com conotações de blooms. Apesar de ser frequente na área, a espécie mostrou preferência pelos locais com maiores concentrações de ortofosfato dissolvido e fósforo total dissolvido e salinidade compreendida no regime mesoalino.

Asunto(s)

RESUMEN

This work presents an innovative methodology to have a rapid diagnosis about the mobility of selected trace elements of known toxicity and biological risk (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn and Zn) present in contaminated sediments. The novel strategy presented in this work uses, therefore, the own estuarine water in contact with sediments as the extracting agent to perform the mobility tests, simulating the real situation of the estuary. This water suffers from different physico-chemical conditions (low and high tides) and gives consequently, rather better information than the one obtained by the routine sequential extraction procedures. The final step of this methodology was the use of spatial modelling by kriging method and multivariate chemometric analysis, both for a better interpretation of the results. To achieve this goal, sediment and water samples were strategically collected at eight different points (four in tributary rivers, one in a closed dock, two in the main channel and another one in the mouth) along the Nerbioi-Ibaizabal River estuary (Metropolitan Bilbao, Basque Country) approximately every three months (summer, autumn, winter and spring) during a whole year. Physico-chemical changes, such as pH, carbonate content and organic matter of the sediments, together with variations in water salinity appear to be responsible for metal mobility from the sediment to the water layer. The influence of these variables was higher in the sites located close to the sea. Moreover, the mobility of trace elements was even higher at high tide in sediments with lower metal content.

Asunto(s)

RESUMEN

Macronutrient elements (C, N and P) and micronutrient elements (Fe, Co, Cu, Zn and Mn) are widely measured in their various physico-chemical forms in open ocean, shelf sea, coastal and estuarine waters. These measurements help to elucidate the biogeochemical cycling of these elements in marine waters and highlight the ecological and socio-economic importance of the oceans. Due to the dynamic nature of marine waters in terms of chemical, biological and physical processes, it is advantageous to make these measurements in situ and in this regard flow injection analysis (FIA) provides a suitable shipboard platform. This review, therefore, discusses the role of FIA in the determination of macro- and micro-nutrient elements, with an emphasis on manifold design and detection strategies for the reliable shipboard determination of specific nutrient species. The application of various FIA manifolds to oceanographic nutrient determinations is discussed, with an emphasis on sensitivity, selectivity, high throughput analysis and suitability for underway analysis and depth profiles. Strategies for enhancing sensitivity and minimizing matrix effects, e.g. refractive index (schlieren) effects and the important role of uncertainty budgets in underpinning method validation and data quality are discussed in some detail.

Asunto(s)

RESUMEN

La llegada al ambiente de bacterias antibiótico-resistentes compromete su calidad higiénico sanitaria. Se analizó la prevalencia de diferentes especies de Enterococcus en aguas del estuario de Bahía Blanca y sus patrones de resistencia a los antibióticos. Se identificaron bioquímicamente 103 aislamientos . Para evaluar la resistencia a antibióticos se implementó la técnica de difusión en agar utilizando discos de vancomicina (Van 30 µg), gentamicina (GenH 120 µg), estreptomicina (StrH 300 µg), teicoplanina (T 30 µg), ampicilina (Am 10 µg) y ciprofloxacina (CIP 5 µg), según normas del Clinical and Laboratory Standards Institute. Se identificaron siete especies de Enterococcus; Enterococcus faecium y Enterococcus faecalis resultaron ser las más frecuentes. El 1,9% de los enterococos presentó resistencia de alto nivel a los aminoglucósidos y no hubo aislamientos con resistencia simultánea a StrH y GenH. El 12,6% de los aislamientos resultó resistente a CIP. No se detectaron resistencias a los glucopéptidos, ni a la Am. El 34% de los aislamientos fue sensible a todos los antibióticos probados. Tradicionalmente, la vigilancia de la dispersión de resistencias bacterianas se realiza con microorganismos de muestras clínicas. Los hallazgos de este trabajo constituyen un dato relevante para el control de cepas resistentes, las que se creían circunscriptas al ámbito hospitalario y que, sin embargo, se encuentran circulando en el ambiente.

The introduction of antibioticresistant bacteria to the environment, affects its hygienic-sanitary quality. The objective of this work is to study the prevalence and the antibiotic resistance patterns of enterococci species isolated from Bahía Blanca estuarine waters. One hundred and three isolates were biochemically identified as Enterococcus spp. The diffusion technique was implemented, by using disks of: vancomycin (Van 30 µg), gentamicin (GenH 120 µg), streptomycin (StrH 300 µg), teicoplanin (T 30 µg), ampicillin (Am 10 µg) and ciprofloxacin (CIP 5 µg) according to the Clinical and Laboratory Standards Institute. Seven Enterococcus species were identified, being Enterococcus faecium and Enterococcus faecalis the most frequent. High level resistance to aminoglycosides was shown by 1.9% of the enterococci whereas 12.6% of the isolates were resistant to CIP. No isolates showed simultaneous resistance to StrH and GenH. Neither resistance to glycopeptides nor to Am was detected. Thirty four per cent of the isolates exhibited susceptibility to all antibiotics tested. Surveillance studies on antimicrobial resistance are usually based upon microorganisms isolated from clinical samples. The findings of this work constitute relevant data for the control of resistant strains, which were believed to be circumscribed to the hospital environment, but are also widespread in the natural sites.

Asunto(s)