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1.
J Environ Sci (China) ; 108: 70-83, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34465438

RESUMO

Iron and nitrate (NO3-) are dominant physiologically required nutrients for phytoplankton growth, and iron may also play a key role in the marine nitrogen cycle. In this study, we investigated the temporal and spatial distributions of dissolved iron (DFe) and Fe(II) in the surface waters of Jiaozhou Bay (JZB) from April 2 to July 26, 2017. High concentrations of DFe and Fe(II) predominantly occurred in nearshore and estuarine stations and concentrations were generally higher in April and May. The highest DFe concentration was observed along the coast of Hongdao (51.55 nmol/L) in May, while the lowest concentration was observed in the western coastal region (2.88 nmol/L) in April. The highest and lowest Fe(II) concentrations were observed in the Licun estuary (22.42 nmol/L) and outer bay (0.50 nmol/L) in May, respectively. We calculated the proportions of nitrate, nitrite, and ammonium in dissolved inorganic nitrogen (DIN) as well as the ratio of Fe(II) to DFe in all four months. The mean Fe(II)/DFe ratio was 0.48 in April, 0.43 in May, 0.69 in June, and 0.32 in July. The mean ratio of NO3- to DIN was 0.78 in April, 0.54 in May, 0.20 in June, and 0.62 in July. NO3-/DIN continuously decreased in the first three months, while Fe(II)/DFe remained high, which suggests that the reduction of iron and nitrate occurred simultaneously in the surface waters of JZB.


Assuntos
Ferro , Nitratos , Baías , Ferro/análise , Fitoplâncton , Água do Mar
2.
Huan Jing Ke Xue ; 42(9): 4341-4349, 2021 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-34414732

RESUMO

Sediment samples were collected from nine sites of three sections, in the intertidal zone of Haizhou bay in July 2018. The abundance and characteristics of microplastics in the sediments (and ragworms within the sediments) were then determined to identify the source of microplastics in ragworms, and to explore the effects of ragworms on microplastics in sediment. The average abundance of microplastics in tidal flat sediments was (0.49±0.17) n·g-1, which was at a high level in domestic offshore environmental studies. Among all the microplastics detected, the most common form and color were fiber and black-gray, respectively, and the materials were mainly polyethylene (PE), polyester (PET), and polystyrene (PS). The detection rate of microplastics in ragworm was 77.78%-86.67%, with an average abundance of (6.68±2.21) n·ind-1; the abundance was significantly correlated with individual mass (r=0.42, P=0.002). The microplastic abundance was significantly higher in ragworms with individual mass over 1.5 g than in those with a mass of<0.5 g or 0.5-1 g (F3=141.029, P=0.000). In ragworms, microplastics were dominated by small black or blue fibers, and the main materials were PE and PET. By analyzing the various characteristics of microplastics with a particle size of 0-3 mm, it was found that the abundance of microplastics in sediments was strongly correlated with that in ragworms (r=0.79,P=0.01); the main form (r=0.90, P=0.035) and the material composition (r=0.73, P=0.024) also showed significant correlation between sediments and ragworms. This indicates that ragworms ingest microplastics in the sedimentary environment and exchange the microplastics with the sediments. Therefore, ragworms can be used as an indicator species of microplastic pollution in sediments.


Assuntos
Microplásticos , Poluentes Químicos da Água , Baías , Monitoramento Ambiental , Sedimentos Geológicos , Plásticos , Poluentes Químicos da Água/análise
3.
Environ Monit Assess ; 193(9): 596, 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34426877

RESUMO

Emerging pollutants and priority substances are of growing concern due to their toxicity potential to aquatic organisms and human health. However, few reports on this issue in marine ecosystems in general and, more specifically, on the Colombian Caribbean coast are available. The aim of this study was to detect these compounds in sediments from Cartagena Bay (CB) and in the Grand Marsh of Santa Marta, GMSM (Ramsar site), in order to determine how they related to in vitro cytotoxicity assays on HepG2 cells of sediment extracts. A total of thirty compounds were detected using GC-MS/MS in fifteen stations during both the rainy and the dry seasons. Sediments from CB had a wide range of different toxicants, with polycyclic aromatic hydrocarbons (PAHs) being the most prevalent (12 PAHs, 5.5-881.6 ng/g). Total PCBs ranged from < LOD to 18.6 ng/g, with PCB 138 being the most common detected congener. Residues of p,p'-DDE, Chlorpyrifos and two organophosphate flame retardants, TEHP and ToTP, were found in most sampling locations. The UV filters 4MBC and homosalate were recurrently found in sediments, and the fragrance galaxolide appeared in all cases, with the greatest concentrations found on a touristic beach. In GMSM, with the exception of deltamethrin, all chemicals evaluated had lower average values than in CB. According to sediment quality guidelines, some sites in CB presented values of PAHs higher than the threshold effects level, while in the marsh, none of the stations exceeded it. HepG2 cells exposed to 1% sediment extracts presented reduced cell viability up to 26%. Cytotoxicity displayed a negative correlation with chlorpyrifos concentration. In short, these data suggest the bay and the marsh have specific contamination fingerprints related to anthropogenic interventions. This research highlights the need to further investigate the ecotoxicological implications of detected chemical stressors in these ecosystems.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Baías , Colômbia , Ecossistema , Monitoramento Ambiental , Humanos , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Áreas Alagadas
4.
Sci Total Environ ; 795: 148881, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34252762

RESUMO

Organic biomarkers, as aliphatic hydrocarbons, are present in sedimentary organic matter and have been largely applied to the evaluation of recent environmental changes in the marine environment around the globe, including the Antarctic continent. Five sediment cores were taken in the Admiralty Bay, South Shetland Archipelago, Antarctica to evaluate changes in the signature of aliphatic hydrocarbons such as n-alkanes (n-C10 to n-C40) and isoprenoids as pristane and phytane, over the last decades. The total n-alkanes concentration ranged from 0.17 to 1.67 µg g-1 (mean = 0.74 ± 0.42) which is considered low and similar to pristine sediments. Aliphatic hydrocarbons present in the sedimentary pool came mostly from terrestrial sources as Antarctic lichens and mosses, and from marine sources as the macroalgae forest debris and emergent macrophytes. Anthropogenic inputs of aliphatic hydrocarbons (e.g., petroleum and their by-products) may be neglected based on the multi-proxy approach used to distinct sources of these organic compounds. In general, no significant changes in the sources of aliphatic hydrocarbons were observed along the sediment cores; however, an increased aliphatic hydrocarbons input registered between 1975 and 1992 may be related to the increase in meltwater runoff and the relatively high abundance of marine producers more adapted to increased sea temperatures.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Regiões Antárticas , Baías , Monitoramento Ambiental , Hidrocarbonetos/análise , Poluentes Químicos da Água/análise
5.
Sci Total Environ ; 796: 149007, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34274670

RESUMO

Although there has been growing interest in using oysters to remediate estuarine eutrophication since the 1980s, the role of oysters in remediation remains controversial. In this study, we took advantage of the intensive oyster farming in a nutrient-enriched estuary to evaluate the control of phytoplankton blooms by oysters. Observing the phytoplankton density variations in March and October, we found that despite doubled nutrient levels in March, oysters kept the phytoplankton density low. This is the first estuary-scale evidence that oysters can effectively suppress phytoplankton blooms. Measuring the isotopic signals in seawater revealed the significant impact of pelagic nitrogen cycling in the estuary. In March, oysters facilitated NO3- removal in the water column by enhancing the coupled phytoplankton assimilation-oyster filtration and denitrification in the sediments. While in October, the oysters-related nitrification could outcompete the removal processes, adding a significant amount of NO3- to the water column. Our study illustrates the influence of massive oysters on pelagic nitrogen cycling in an "oyster-remediated" estuary, providing implications for restoring oyster reefs to mitigate the symptoms of estuarine eutrophication.


Assuntos
Ostreidae , Fitoplâncton , Animais , Baías , Ecossistema , Eutrofização , Nitrogênio/análise
6.
Mar Pollut Bull ; 169: 112345, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34238565

RESUMO

In this study, heavy metal levels in sediments, human hair, and fish muscle tissue as well as organic matter (OM%) content in surface sediments of Chabahar Bay were determined to assess their ecological risks and sources. Totally, 96 samples were collected from 16 stations (Tiss, Konarak, desalination plant, entrance of Chabahar Bay, Posm, Ramin, and reference stations) and were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Abundances of elements were of the following order: Ca>Al>Fe>Mg>Na>K>S>P>Ti>Mn>Sr>Ba>Cr>Ni>V>Li>Zn>Cu>Co>Pb>As>Cd>Ag>Se>Sb>Be>Mo>Bi. Element levels in sediments were within the range of low pollution areas, except for Cr, As, Ni, and Cd. Dominant sources of elements were natural, except for Cd, which was anthropogenic. All geo-accumulation index (Igeo) values were less than zero, except for Ag, Cd, and Sr from heavily to moderately contaminated areas. Eri values indicated low ecological risk, except for Cd which showed a high ecological risk. The As levels limit the consumption of fish meal per month.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Animais , Baías , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Irã (Geográfico) , Metais Pesados/análise , Medição de Risco , Poluentes Químicos da Água/análise
7.
Mar Pollut Bull ; 170: 112653, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34198152

RESUMO

We extracted and analyzed microplastics (MP) in archived sediment cores from Great Bay Estuary (GBE) in the Gulf of Maine region of North America. Results indicated that MP are distributed in GBE sediments, 0-30 cm, at an average occurrence of 116 ± 21 particles g-1 and that morphology varies by site and depth. Analysis by sediment depth and age class indicated that MP accumulation increased over several decades but recently (5-10 years) has likely begun to decrease. Hydrodynamic and particle transport modeling indicated that bed characteristics are a more controlling factor in MP distribution than typical MP properties and that the highest accumulation likely occurs in regions with weaker hydrodynamic flows and lower bed shear stress, e.g., eelgrass meadows and along fringes of the Bay. These results provide a baseline and predictive understanding of the occurrence, morphology, and sedimentation of MP in the estuary.


Assuntos
Microplásticos , Poluentes Químicos da Água , Baías , Monitoramento Ambiental , Estuários , Sedimentos Geológicos , Plásticos , Poluentes Químicos da Água/análise
8.
Mar Pollut Bull ; 170: 112674, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34225192

RESUMO

Identifying trophic status shift and developing nutrient criteria were considered important for controlling coastal eutrophication. Based on data from 1980 to 2018, we used sequential t-test analysis of regime shifts and assessment of coastal trophic status models to detect regime shifts in trophic status in Bohai Bay (China). We identified four distinct periods: unimpaired (1980-1984), minimally impacted (1985-1994), tipping point (1995-1999) and severely degraded (2000-2018). Using the reference conditions at different trophic status, a frequency distribution analysis was performed to develop candidate nutrient criteria. By considering other factors, such as the quantity and quality of data and long-term nutrient variations, we determined recommended criteria for dissolved inorganic nitrogen (15.3 µmol L-1) and phosphorus (0.42 µmol L-1) in Bohai Bay. This study provides a novel and feasible approach to determine reference conditions for the determination of nutrient criteria for coastal waters.


Assuntos
Baías , Monitoramento Ambiental , China , Eutrofização , Nitrogênio/análise , Nutrientes , Fósforo/análise
9.
J Environ Manage ; 297: 113316, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34293673

RESUMO

Agriculture and the food system emit a considerable amount of Greenhouse Gas (GHG) emissions in the atmosphere. Hence, current researchers, policymakers, and other stakeholders are calling for improving the environmental performance of agriculture. This study utilizes the countries of The Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) to investigate the effect of agriculture value-added, pesticide use, renewable energy adoption, human capital, and economic growth on greenhouse gas emissions. The moderation effect of renewable energy use and human capital is also introduced to see whether they can offset agriculture's emissions in these BIMSTEC economies. Having reported a state-of-the-art literature review, the econometric procedure applies the second-generation unit root tests, panel cointegration and panel quantile regression for three preferred model specifications. The result from the Panel quantile regression method reveals a U-shaped relationship between agriculture value-added and greenhouse gas emissions, suggesting the significance of a small farming system. Human capital has a negative effect, whereas pesticide use has a positive effect on greenhouse gas emissions. Furthermore, the moderation effect of human capital and pesticide use suggests that human capital is not significant enough to offset the effect of pesticide use on the greenhouse gas emissions, whereas the interaction of renewable and pesticide use suggests that renewable energy adoption in the agriculture sector can mitigate the effect of pesticide use on GHG emissions. Finally, the conclusions of the study support the achievement of few sustainable development goals.


Assuntos
Gases de Efeito Estufa , Agricultura , Baías , Dióxido de Carbono/análise , Desenvolvimento Econômico , Efeito Estufa , Gases de Efeito Estufa/análise , Humanos , Energia Renovável
10.
Huan Jing Ke Xue ; 42(8): 3808-3819, 2021 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-34309267

RESUMO

The US Environmental Protection Agency has listed 16 polycyclic aromatic hydrocarbons (PAHs) for priority control. Soil samples from Xiangxi Bay in the Three Gorges Reservoir Area (the water fluctuation zone, WLFZ; upper edge of water fluctuation zone, UEWLFZ; sediments) were analyzed for the concentration of these PAHs, using high performance liquid chromatography (HPLC). The results showed that the soil samples of Xiangxi Bay could be ranked, based on the concentration of PAHs, in the following order:UEWLFZ>WLFZ>sediment. The composition of PAHs varied from the three regions, with 3- and 4-ring PAHs dominating in sediments and 4- and 5-ring PAHs dominating in soil from the WLFZ and UEWLFZ. The composition of PAHs in soil from the WLFZ exhibited a higher coefficient of variation and a weaker correlation with the composition of PAHs in soil from the UEWLFZ and sediment. Soil from the three regions showed varying seasonal distributions of PAHs, which is closely related to the quantity and types of energy consumption in each season. PAHs in sediment from sites at the same altitude showed no evident differences, whereas WLFZ and UEWLFZ soil had higher levels of PAHs at the sites near Xiakou Town and the Yangtze River Estuary. Isomer ratio analysis showed that the sources of PAHs in Xiangxi Bay vary between seasons and regions, with incomplete combustion of fossil fuels and biomass forming the main sources in the soil of Xiangxi Bay. The lifetime carcinogenic risk assessment shows that PAHs in sediment, WLFZ, and UEWLFZ have a potential risk to human through ingestion and dermal contact, with PAHs in the soil of UEWLFZ posing the highest carcinogenic risk. The results provide a theoretical reference for the prevention and control of contamination by PAHs in Xiangxi Bay of the Three Gorges Reservoir area.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Baías , China , Cidades , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Solo , Poluentes Químicos da Água/análise
11.
Mar Environ Res ; 169: 105407, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34252862

RESUMO

Protists are an important component of the marine ecosystem and play an essential role in material cycle and energy flow, but the distribution of protists in coral reefs have not been fully studied. In this study, high-throughput amplicon sequencing technology was used to study the biodiversity and community structure of protists from coral reefs and open sea areas, with the typical semi-enclosed bay Daya Bay as the research field. There were significant seasonal differences in the dominant phyla of protists, biodiversity index values and ßeta diversity (P < 0.05) but no significant differences in the different sampling areas (P > 0.05). The topological parameters of the co-occurrence network showed the protist co-occurrence network in the open sea had more complex interactions and stronger stability than in the coral reef areas because of the hydrodynamics, waves, and relatively poor nutrients. Redundancy analysis and the Mantel test showed that the structure of the protist community was affected by seawater temperature, pH, salinity, and dissolved oxygen. This study analysed the temporal and spatial differences in protists in the coral reef and open sea areas of Daya Bay to provide important information for the study of protist biodiversity and community structure in semi-enclosed bays.


Assuntos
Antozoários , Recifes de Corais , Animais , Baías , Biodiversidade , Ecossistema , Oceanos e Mares , Estações do Ano , Água
12.
Artigo em Inglês | MEDLINE | ID: mdl-34207818

RESUMO

Contaminants of Emerging Concern (CECs) with estrogenic or estrogenic-like activity have been increasingly detected in aquatic environments and have been an issue of global concern due to their potential negative effects on wildlife and human health. This study used the MCF-7 cell proliferation assay (E-Screen) to assess the estrogenic activity profiles in Maryland Coastal Bays (MCBs), a eutrophic system of estuaries impacted by human activities. Estrogenic activity was observed in all study sites tested. Water samples from MCBs increased MCF-7 cell proliferation above the negative control from 2.1-fold at site 8, located in Sinepuxent Bay close to the Ocean City Inlet, to 6.3-fold at site 6, located in Newport Bay. The proliferative effects of the sediment samples over the negative control ranged from 1.9-fold at the Assateague Island National Seashore site to 7.7-fold at the Public Landing site. Moreover, elevated cell proliferation (p < 0.05) was observed when cells were co-exposed with 17ß-Estradiol (E2), while reduction in cell proliferation was observed when cells were co-exposed with the antagonist ICI 182, 780 suggesting that cell proliferative effects were primarily mediated by the estrogen receptor (ER). These results suggest the occurrence of some estrogenic or hormonal-like compounds in the MCBs and are consistent with our previous findings based on vitellogenin analyses.


Assuntos
Baías , Estrogênios , Proliferação de Células , Humanos , Células MCF-7 , Maryland
13.
Environ Monit Assess ; 193(8): 471, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226964

RESUMO

Shellfish-growing areas in marine environments are affected by pollutants that mainly originate from land, including streams, domestic wastewater, and the effluents of wastewater treatment plants (WWTPs), which may function as reservoirs of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs). The objective of this study was to identify the occurrence and distribution of antibiotic resistance at five oyster sampling sites and 11 major inland pollution sources in the drainage basin of Kamak Bay, Republic of Korea. Culture-based methods were used to estimate the diversity and abundance of antibiotic-resistant Escherichia coli strains isolated from oysters and major inland pollution sources. The percentages of ARB and multiple antibiotic resistance index values were significantly high in discharge water from small fishing villages without WWTPs. However, the percentages of antibiotic-resistant E. coli isolates from oysters were low, as there was no impact from major inland pollutants. Fourteen ARGs were also quantified from oysters and major inland pollution sources. Although most ARGs except for quinolones were widely distributed in domestic wastewater discharge and effluent from WWTPs, macrolide resistance genes (ermB and msrA) were detected mainly from oysters in Kamak Bay. This study will aid in tracking the sources of antibiotic contamination in shellfish to determine the correlation between shellfish and inland pollution sources.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Frutos do Mar/microbiologia , Baías , Monitoramento Ambiental , Escherichia coli/genética , Genes Bacterianos , Macrolídeos , República da Coreia , Águas Residuárias/análise
14.
Sci Rep ; 11(1): 15110, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34302017

RESUMO

The lockdown measures that were taken to combat the COVID-19 pandemic minimized anthropogenic activities and created natural laboratory conditions for studying air quality. Both observations and WRF-Chem simulations show a 20-50% reduction (compared to pre-lockdown and same period of previous year) in the concentrations of most aerosols and trace gases over Northwest India, the Indo Gangetic Plain (IGP), and the Northeast Indian regions. It is shown that this was mainly due to a 70-80% increase in the height of the boundary layer and the low emissions during lockdown. However, a 60-70% increase in the pollutants levels was observed over Central and South India including the Arabian sea and Bay of Bengal during this period, which is attributed to natural processes. Elevated (dust) aerosol layers are transported from the Middle East and Africa via long-range transport, and a decrease in the wind speed (20-40%) caused these aerosols to stagnate, enhancing the aerosol levels over Central and Southern India. A 40-60% increase in relative humidity further amplified aerosol concentrations. The results of this study suggest that besides emissions, natural processes including background meteorology and dynamics, play a crucial role in the pollution concentrations over the Indian sub-continent.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Emissões de Veículos/análise , Aerossóis/análise , África , Baías , COVID-19 , Controle de Doenças Transmissíveis , Correlação de Dados , Poeira/análise , Poluição Ambiental/análise , Humanos , Índia , Meteorologia , Oriente Médio , Oceanos e Mares , Pandemias
15.
Sci Total Environ ; 795: 148639, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34328932

RESUMO

Fast and comprehensive monitoring of VOCs, required for air quality management in large-scale chemical industrial parks in China, cannot be accomplished by stationary measurements using conventional GC-FID or GC-MS alone due to their low temporal resolutions and limited detectable ranges. Novel direct-inlet mass spectrometry (DI-MS) has been widely applied for real-time monitoring of VOCs. To verify its applicability in industrial settings, high mass-resolution proton-transfer-reaction time-of-flight MS (HMR-PTR-TOFMS), single-photon ionization time-of-flight MS (SPI-TOFMS), together with online GC-FID/MS were simultaneously deployed at the boundary of one of the largest chemical industrial parks in eastern China. Aromatics, acetonitrile, acetic acid, ethyl acetate, aliphatic hydrocarbons, 1,2-dichloroethane, and acetone were detected as the main pollutants. These three instruments detected 12 common species, among which ethyl acetate, toluene, C8-aromatics, and methyl ethyl ketone showed similar time series and levels. Acetone, benzene, chlorobenzene, styrene, and C9-aromatics showed only similar time series. The HMR-PTR-TOFMS uniquely detected 14 species, mainly oxidized VOCs, nitriles, and amines, which greatly helps acknowledge the pollutants in the chemical industrial area. Positive matrix factorization, using the HMR-PTR-TOFMS and GC-FID/MS datasets, was used to identify eight sources. Four of the identified sources were mainly detected by the HMR-PTR-TOFMS, with pollutants mainly comprised of nitriles, amines, carbonyls, and organic acids, most of which were hazardous and/or odorous. These four sources accounted for 41.5% and 33.2% of the total VOCs and ozone formation potential, respectively. The complementary nature of GC-FID/MS and HMR-PTR-TOFMS in VOC source apportionment in industrial settings is of great practical use for advanced VOCs abatement. Thus, the high mass resolution DI-MSs are suggested to be a supplementary measurement for fence-line monitoring. Although with a relatively short period attempt, this study has wide implications for the fence-line stationary observational modes and source apportion methods combining with traditional observations.


Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Baías , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Compostos Orgânicos Voláteis/análise
16.
Environ Pollut ; 287: 117588, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34153606

RESUMO

Endocrine-disrupting chemicals (EDCs) in water are receiving particular attention as they pose adverse effects on aquatic systems, even at trace concentrations. A comprehensive study was conducted on 14 EDCs (five estrogens and nine household and personal care products (HPCPs)) in the water of the urbanized Jiaozhou Bay in the Yellow Sea during summer and winter. Results showed that the total concentration of 14 EDCs ranged from 100 to 658 ng L-1 and 56.7-212 ng L-1 in the estuarine and bay water, respectively. The average total concentration of five estrogens in summer was significantly (p < 0.05) lower than that in winter due to the higher precipitation dilution and degradations during summer, whereas the average total concentration of nine HPCPs was significantly (p < 0.05) higher during the summer than that during the winter because of the higher usage and emissions during the summer. Estrogens and HPCPs were dominated by 17α-ethinylestradiol and p-hydroxybenzoic acid (PHBA), respectively. High PHBA concentrations may be related to the hydrolysis of parabens. The total concentrations of EDCs were higher in the eastern coastal seawater of the bay due to the strong influence of domestic and industrial wastewater discharge. Estrogens may interfere with the endocrine system of aquatic organisms in the bay because the total estradiol equivalent concentration exceeded 1 ng L-1. 17α-ethinylestradiol was the main contributor to the estrogenic activity. The EDC mixtures posed high risks (RQ > 1) to mollusks, crustaceans, and fish, and low to moderate risks (RQ < 1) to algae. Fish was the most sensitive aquatic taxon to the EDC mixtures. Given the concentration and frequency of EDCs, the optimized risk quotient method revealed that 17α-ethinylestradiol, estrone, triclocarban, triclosan, and 17ß-estradiol should be prioritized in ecological management because of their high risks (prioritization index of >1).


Assuntos
Disruptores Endócrinos , Poluentes Ambientais , Poluentes Químicos da Água , Animais , Baías , China , Disruptores Endócrinos/análise , Monitoramento Ambiental , Estrogênios/análise , Medição de Risco , Poluentes Químicos da Água/análise
17.
Sci Total Environ ; 791: 148280, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34119789

RESUMO

Coastal beaches are a vital transitional zone in which terrestrial microplastics (MPs) enter the oceans. However, little is known about the impact of coastal currents on the dispersion and accumulation of MPs, especially in semi-enclosed bays. To address this knowledge gap, we investigated the spatiotemporal variation of MPs in the coastal sediments of Haizhou Bay. The abundance of MPs ranged from 10.94 n/kg to 1309.02 n/kg. Overall, a higher amount of MPs was found in intertidal sediment than in the supratidal zone. Significant seasonal variation was observed only in the intertidal areas of Haizhou Bay, suggesting that hydrodynamics plays a critical role shaping MP abundance. Statistical analyses revealed a roughly exponential increase of MP abundance with distance from the coast, and that a relatively higher abundance of MPs would be found at offshore sites in downstream areas. These results suggest that coastal currents are important contributors of MPs. A numerical model of vertical profiles estimated the total inventory of MPs in coastal areas to be 13.83-580 trillion pieces. Our results suggest a neglected sink of MPs in the sedimentary environments of coastal regions. As a result, the amount of MPs in coastal regions in previous studies could have been underestimated.


Assuntos
Microplásticos , Poluentes Químicos da Água , Baías , Monitoramento Ambiental , Sedimentos Geológicos , Plásticos , Poluentes Químicos da Água/análise
18.
Water Res ; 201: 117329, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34161874

RESUMO

Sea level rise has increased the frequency of tidal flooding even without accompanying precipitation in many coastal areas worldwide. As the tide rises, inundates the landscape, and then recedes, it can transport organic and inorganic matter between terrestrial systems and adjacent aquatic environments. However, the chemical and biological effects of tidal flooding on urban estuarine systems remain poorly constrained. Here, we provide the first extensive quantification of floodwater nutrient concentrations during a tidal flooding event and estimate the nitrogen (N) loading to the Lafayette River, an urban tidal sub-tributary of the lower Chesapeake Bay (USA). To enable the scale of synoptic sampling necessary to accomplish this, we trained citizen-scientist volunteers to collect 190 flood water samples during a perigean spring tide to measure total dissolved N (TDN), dissolved inorganic N (DIN) and phosphate concentrations, and Enterococcus abundance from the retreating ebb tide while using a phone application to measure the extent of tidal inundation. Almost 95% of Enterococcus results had concentrations that exceeded the standard established for recreational waters (104 MPN 100 mL-1). Floodwater dissolved nutrient concentrations were higher than concentrations measured in natural estuarine waters, suggesting floodwater as a source of dissolved nutrients to the estuary. However, only DIN concentrations were statistically higher in floodwater samples than in the estuary. Using a hydrodynamic model to calculate the volume of water inundating the landscape, and the differences between the median DIN concentrations in floodwaters and the estuary, we estimate that 1,145 kg of DIN entered the Lafayette River during this single, blue sky, tidal flooding event. This amount exceeds the annual N load allocation for overland flow established by federal regulations for this segment of the Chesapeake Bay by 30%. Because tidal flooding is projected to increase in the future as sea levels continue to rise, it is crucial we quantify nutrient loading from tidal flooding in order to set realistic water quality restoration targets for tidally influenced water bodies.


Assuntos
Baías , Nitrogênio , Monitoramento Ambiental , Estuários , Inundações , Humanos , Nitrogênio/análise , Rios
19.
Mar Pollut Bull ; 170: 112656, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34186449

RESUMO

Nickel bioaccumulation capacity of a marine Brevibacterium sp., designated as X6, was evaluated to explore its potential application in the bioremediation of Ni2+ pollutants in marine environments. The minimum Ni2+ inhibitory concentration and maximum Ni2+ bioaccumulation of X6 were 1000 mg/L and 100.95 mg/g, respectively, higher than most reported strains. Among the co-existing metal ions in seawater, K+ caused a slight adverse impact on Ni2+ uptake, followed by Na+ and Ca2+, whereas Mg2+ drastically inhibited Ni2+ bioaccumulation. Other heavy metals such as Co2+, Zn2+ and Cd2+ moderately affected Ni2+ binding, but the adverse effect of Cu2+ was severe. The investigation of the mechanism of Ni2+ bioaccumulation revealed that 66.34% of the accumulated Ni2+ was bound to the cell surface. Carboxylic, hydroxyl, amino and thiol groups participated in Ni2+ binding, while carboxylic group contributed the most, while thiol group may be more involved in Ni2+ binding at low Ni2+ concentrations.


Assuntos
Brevibacterium , Metais Pesados , Poluentes Químicos da Água , Baías , Bioacumulação , China , Metais Pesados/análise , Níquel/análise , Poluentes Químicos da Água/análise
20.
Harmful Algae ; 106: 102066, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34154783

RESUMO

Although the occurrences of harmful algal blooms (HABs) have been intensifying, many HABs in coastal waters may have been neglected despite their damaging impact directly on ecology and indirectly on human and animal health. The current detection of HABs depends primarily on the water coloration, chlorophyll intensity, cell density, and mortality due to HAB toxicity. Such methods may not be adequately sensitive to detecting HABs that are relatively transient or small scale. The Bohai Sea is the largest inlet of the Yellow Sea located on the northeast coast of China and famous for shipping and marine aquacultures. HABs frequently occur in the Bohai Sea. In this study, we explored the composition, diversity, and distribution of HAB species using the metabarcoding approach. Through sequencing and the analyzing the 18S rDNA V4 region of 15 samples collected from spatially isolated sites in the Bohai Sea during an expedition in the summer of 2019, we identified 74 potential HAB species including 34 that had not been reported in the Bohai Sea in previous studies. This project provided a detailed analysis of phytoplankton composition, and molecular detection of HAB species in the Bohai Sea. In particular, these analyses revealed extremely high relative abundances of the ichthyotoxic phytoplankton species Vicicitus globosus (Dictyochophyceae) at multiple adjacent sampling sites in the Bohai Bay, which were close to the Yellow River Estuary during the expedition. The results revealed the occurrence of a potential HAB event that would be otherwise undetected using conventional methods, highlighting the sensitivity and power of metabarcoding analysis in detecting HABs and HAB species. This research suggested the value for routine and long-term monitoring of HAB species as an approach for monitoring HABs.


Assuntos
Proliferação Nociva de Algas , Fitoplâncton , Animais , Aquicultura , Baías , Fitoplâncton/genética , Estações do Ano
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