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1.
Int. microbiol ; 22(4): 501-509, dic. 2019. ilus, graf, tab
Artigo em Inglês | IBECS | ID: ibc-185068

RESUMO

Singleplex and duplex loop-mediated isothermal amplification (LAMP) assays were developed for detecting Vibrio anguillarum, a major bacterial pathogen of fish, and Vibrio alginolyticus, a pathogen of fish and humans, separately and simultaneously from contaminated seawater by targeting the groEL gene of V. anguillarum, which encodes a molecular chaperone protein, and the fklB gene of V. alginolyticus, which encodes a 22 kilodalton (kDa) peptidyl prolyl isomerase. The optimal reaction conditions to produce consistent results were 65°C for 30 min, 63°C for 30 min, and 63°C for 40 min for the groEL (singleplex for V. anguillarum), fklB (singleplex for V. alginolyticus), and groEL + flkB (duplex) LAMP assays, respectively, analyzed via visual detection methods (use of calcein, and SYBR Green I) and agarose gel electrophoresis. The assays were found to be species-specific, as closely related Vibrio spp. were not detected. The limits of detection (LoDs) of the LAMP assays for DNA template from pure culture and artificially contaminated seawater were 10 and 14 fg (groEL assay; for V. anguillarum), 12.5 and 17 fg (fklB assay; for V. alginolyticus), and 50 and 70 fg (duplex assay) per reaction, respectively, which were much better than the LoDs of conventional polymerase chain reaction (PCR). Singleplex and duplex LAMP assays were found to be rapid, species-specific, and sensitive for the detection of V. anguillarum and V. alginolyticus and are applicable to laboratory and field diagnostics


No disponible


Assuntos
Humanos , Animais , Vibrio alginolyticus/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Vibrio/química , Vibrio/crescimento & desenvolvimento , Peixes/microbiologia , Água do Mar/análise , Água do Mar/microbiologia , Reação em Cadeia da Polimerase
2.
Environ Monit Assess ; 191(11): 696, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667673

RESUMO

Tunisia relies extensively on coastal groundwater resources that are pumped at unsustainable rates to support irrigated agriculture, causing groundwater drawdown and water quality problems due to seawater intrusion. It is imperative for the country to regulate future groundwater allocations and implement conservation strategies based on robust hydrogeological assessments to alleviate the adverse impacts of groundwater depletion. We developed a 3D transient density-dependent groundwater model by coupling MODFLOW-2000 and MT3DMS to improve understanding of seawater intrusion into the Korba aquifer in Tunisia. Results indicate that groundwater overexploitation since 1965 induced 5.15 Mm3/year of seawater inflow while reducing submarine discharge into the sea by about 9.74 Mm3/year as compared to the steady state water budget in 1965. Projecting withdrawals from 2014 up to 2050 results in a slow but extensive groundwater table decline forming a cone of depression 15 m below sea level. The seawater wedge under this business-as-usual scenario is expected to reach 1.8 km from the shoreline, causing significant mixing of the TDS-rich seawater in the aquifer system. The cone of depression under a 25% increase in groundwater withdrawal drops to about 20 m below sea level while the saltwater front reaches 2.5 km inland. Countering the seawater intrusion problem requires reducing groundwater pumping by 17 Mm3/year to push back the saltwater front along the coastline by about 25% over a 43-year period. Application of the presented generic groundwater simulation framework guides developing management strategies to mitigate seawater intrusion in the Korba coastal aquifer and similar areas.


Assuntos
Monitoramento Ambiental , Água Subterrânea/análise , Água do Mar/análise , Previsões , Tunísia , Qualidade da Água
3.
Anal Bioanal Chem ; 411(27): 7251-7260, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31612256

RESUMO

Chloride widely exists in the environment and will cause serious interference for arsenic speciation analysis. The determination of four arsenic species including arsenite (As(III)), arsenate (As(V)), monomethylarsenate (MMA), and dimethylarsonate (DMA) in samples containing high concentrations of Cl- was carried out in this work by coupling of liquid chromatography (LC) with hydride generation atomic fluorescence spectrometry (HG-AFS). The interference of Cl- was successfully eliminated by coupling two anion-exchange chromatographic columns in series and eluting with 35.0 mmol L-1 (NH4)2HPO4 (pH = 6.00). A novel pre-treatment system was subsequently developed to realize on-line column switch and pre-reduction of As(V). The analysis time was shortened by an isocratic elution but programmed flow rate method, and the sensitivity of As(V) was also enhanced by the introduction of pre-reduction using the developed system. The proposed method can resist at least 10 g L-1 Cl- without any pre-treatment operations. Since LC-HG-AFS is low-cost and can be afforded or self-assembled by most labs, the developed method can be adopted as a routine analysis method for arsenic species in chloride-bearing samples, such as urine and seawater. Graphical abstract.


Assuntos
Arseniatos/análise , Arsenicais/análise , Arsenitos/análise , Poluentes Químicos da Água/análise , Arseniatos/urina , Arsênico/análise , Arsênico/urina , Arsenicais/urina , Arsenitos/urina , Cloretos/análise , Cloretos/urina , Cromatografia Líquida de Alta Pressão/instrumentação , Desenho de Equipamento , Humanos , Limite de Detecção , Metilação , Água do Mar/análise , Espectrometria de Fluorescência/instrumentação , Espectrofotometria Atômica/instrumentação , Poluentes Químicos da Água/urina
4.
Mar Pollut Bull ; 145: 455-462, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590810

RESUMO

Marine litter pollution has become a complex global problem, because of the negative ecological and socioeconomic impacts as well as the human health risks that it represents. In Colombia, mangroves are affected by inadequate solid waste management, which results in litter accumulation. Additionally, the information related to this problem is limited avoiding the development of prevention and reduction strategies. For the first time, pollution by marine litter and microplastics were evaluated in mangrove soils of the Ciénaga Grande de Santa Marta, where 540 ±â€¯137 and 31 ±â€¯23 items/ha of marine litter were determined in mangroves near and away from populated centers respectively. Plastics represented between 73 and 96% of litter, and microplastic quantity oscillated between 31 and 2,863 items/kg finding the highest concentrations in mangroves near to the population. This study contributes to the knowledge of the marine litter problem in mangroves of the Colombian Caribbean, becoming a help for their conservation.


Assuntos
Plásticos/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Colômbia , Poluição Ambiental , Humanos , Água do Mar/análise , Solo/química
5.
Mar Pollut Bull ; 145: 463-473, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590811

RESUMO

Microplastics (plastic particles <5 mm) are an emerging concern in Arctic sea ice with measured concentrations orders of magnitude higher than in surface seawater. However, incorporation of microplastics into sea ice, and their impact on sea ice properties, is unknown. We added microplastic particles in a microcosm experiment to determine microplastic distributions and effects on sea ice properties. Microplastic additions did not affect sea ice growth, but high concentrations of microplastics at the ice surface resulted in high ice salinity and changes in sea ice albedo. Field studies in the Gulf of Bothnia (Baltic Sea) showed sea ice concentration of microplastics from 8 to 41 particles per liter of melted ice, wich were much lower than those found to impact sea ice properties in the microcosm experiments. However, should microplastic concentrations increase, microplastic incorporation in sea ice may impact sea ice albedo.


Assuntos
Camada de Gelo/química , Plásticos/análise , Água do Mar/análise , Regiões Árticas , Países Bálticos , Monitoramento Ambiental , Poluentes Químicos da Água/análise
6.
Mar Pollut Bull ; 145: 474-479, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590813

RESUMO

This baseline study highlights the 210Po and 210Pb concentration in seven macroalgae species from the northern Gulf that are frequently washed ashore during the bloom season from February to April. The highest concentrations of 210Po and 210Pb were 2.947 ±â€¯0.032 and 1.057 ±â€¯0.145 Bq kg-1 wwt, respectively, in brown algae Sargassum boveanum, and the lowest in green algae Ulva prolifera with 1.533 ±â€¯0.058 and 0.170 ±â€¯0.069 Bq kg-1 wwt, respectively. A 210Po enrichment was observed in both brown and green algae species, with the 210Po/210Pb ratio being >1 for all the samples. The mean concentration of 210Po in all species was an order of magnitude higher than 210Pb, and the difference in mean concentration is statistically significant (p < 0.001). At the same time, the mean concentration of dissolved 210Po and 210Pb in seawater was 0.28 ± 0.01 and 0.52 ± 0.01Bq m-3 with a 210Po/210Pb ratio of 0.54 ± 0.02 indicating that 210Po was absorbed from water and more concentrated by macroalgae. The measured concentration factor (CF) for 210Po in these macroalgae for the northern Gulf varied between 5 × 103-1 × 104, higher than the IAEA recommended value of 1 × 103 which suggests that a revision of that value may be needed. The field derived CFs for 210Pb vary between 3 × 102-1.8 × 103, comparable to the ICRP recommended value of 2 × 103.


Assuntos
Radioisótopos de Chumbo/análise , Polônio/análise , Sargassum/química , Alga Marinha/química , Ulva/química , Monitoramento Ambiental , Oceano Índico , Estações do Ano , Água do Mar/análise
7.
Mar Pollut Bull ; 145: 96-104, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590839

RESUMO

Coastal water clarity varies at high temporal and spatial scales due to weather, climate, and human activity along coastlines. Systematic observations are crucial to assessing the impact of water clarity change on aquatic habitats. In this study, Secchi disk depths (ZSD) from Boston Harbor, Buzzards Bay, Cape Cod Bay, and Narragansett Bay water quality monitoring organizations were compiled to validate ZSD derived from Landsat 8 (L8) imagery, and to generate high spatial resolution ZSD maps. From 58 L8 images, acceptable agreement was found between in situ and L8 ZSD in Buzzards Bay (N = 42, RMSE = 0.96 m, MAPD = 28%), Cape Cod Bay (N = 11, RMSE = 0.62 m, MAPD = 10%), and Narragansett Bay (N = 8, RMSE = 0.59 m, MAPD = 26%). This work demonstrates the value of merging in situ ZSD with high spatial resolution remote sensing estimates for improved coastal water quality monitoring.


Assuntos
Monitoramento Ambiental/métodos , Imagens de Satélites , Água do Mar/análise , Poluição da Água/análise , Qualidade da Água , Boston , Ecossistema
9.
Nature ; 574(7777): 237-241, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31578526

RESUMO

Earth is heading towards a climate that last existed more than three million years ago (Ma) during the 'mid-Pliocene warm period'1, when atmospheric carbon dioxide concentrations were about 400 parts per million, global sea level oscillated in response to orbital forcing2,3 and peak global-mean sea level (GMSL) may have reached about 20 metres above the present-day value4,5. For sea-level rise of this magnitude, extensive retreat or collapse of the Greenland, West Antarctic and marine-based sectors of the East Antarctic ice sheets is required. Yet the relative amplitude of sea-level variations within glacial-interglacial cycles remains poorly constrained. To address this, we calibrate a theoretical relationship between modern sediment transport by waves and water depth, and then apply the technique to grain size in a continuous 800-metre-thick Pliocene sequence of shallow-marine sediments from Whanganui Basin, New Zealand. Water-depth variations obtained in this way, after corrections for tectonic subsidence, yield cyclic relative sea-level (RSL) variations. Here we show that sea level varied on average by 13 ± 5 metres over glacial-interglacial cycles during the middle-to-late Pliocene (about 3.3-2.5 Ma). The resulting record is independent of the global ice volume proxy3 (as derived from the deep-ocean oxygen isotope record) and sea-level cycles are in phase with 20-thousand-year (kyr) periodic changes in insolation over Antarctica, paced by eccentricity-modulated orbital precession6 between 3.3 and 2.7 Ma. Thereafter, sea-level fluctuations are paced by the 41-kyr period of cycles in Earth's axial tilt as ice sheets stabilize on Antarctica and intensify in the Northern Hemisphere3,6. Strictly, we provide the amplitude of RSL change, rather than absolute GMSL change. However, simulations of RSL change based on glacio-isostatic adjustment show that our record approximates eustatic sea level, defined here as GMSL unregistered to the centre of the Earth. Nonetheless, under conservative assumptions, our estimates limit maximum Pliocene sea-level rise to less than 25 metres and provide new constraints on polar ice-volume variability under the climate conditions predicted for this century.


Assuntos
Água do Mar/análise , Dióxido de Carbono/análise , Foraminíferos/química , Sedimentos Geológicos/química , História Antiga , Camada de Gelo/química , Nova Zelândia , Oceanos e Mares , Isótopos de Oxigênio/análise , Pressão Parcial
10.
Isotopes Environ Health Stud ; 55(6): 566-587, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31578875

RESUMO

The stable isotopes of oxygen and hydrogen can provide useful insights into water origin and hydrological processes. The present study aims to investigate the characteristics of stable H/O isotopes of groundwater and surface water in a coastal area of the Vietnamese Mekong Delta. Isotopes and chloride concentrations of surface water show a highly seasonal and linearly spatial variability, depending on the distance to the sea. The seasonal variation of upstream discharge and rainfall plays an important role in changes of the isotopic compositions and chloride concentrations. Tide also influences on chloride concentrations of surface water while it does not change the isotopic compositions. Evaporation plays a crucial role in changes of isotopic compositions, while the influence of freshwater/seawater mixing on isotopic variabilities is negligible. Groundwater has a spatial heterogeneity in isotopic compositions and chloride concentrations, reflecting different recharge sources and seawater intrusion processes. Groundwater in shallow aquifers originates from rainfall and surface water with small evaporative losses, and it experienced different magnitudes of mixing with seawater. Groundwater in deep aquifers might be recharged by open-surface water evaporation in the last glacial age with minor impacts of seawater intrusion on these aquifers.


Assuntos
Monitoramento Ambiental/métodos , Água Doce/análise , Água Subterrânea/análise , Água do Mar/análise , Recursos Hídricos/provisão & distribução , Deutério/análise , Água Doce/química , Água Subterrânea/química , Isótopos de Oxigênio/análise , Água do Mar/química , Vietnã
11.
Nature ; 574(7777): 233-236, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31471591

RESUMO

Reconstructing the evolution of sea level during past warmer epochs such as the Pliocene provides insight into the response of sea level and ice sheets to prolonged warming1. Although estimates of the global mean sea level (GMSL) during this time do exist, they vary by several tens of metres2-4, hindering the assessment of past and future ice-sheet stability. Here we show that during the mid-Piacenzian Warm Period, which was on average two to three degrees Celsius warmer than the pre-industrial period5, the GMSL was about 16.2 metres higher than today owing to global ice-volume changes, and around 17.4 metres when thermal expansion of the oceans is included. During the even warmer Pliocene Climatic Optimum (about four degrees Celsius warmer than pre-industrial levels)6, our results show that the GMSL was 23.5 metres above the present level, with an additional 1.6 metres from thermal expansion. We provide six GMSL data points, ranging from 4.39 to 3.27 million years ago, that are based on phreatic overgrowths on speleothems from the western Mediterranean (Mallorca, Spain). This record is unique owing to its clear relationship to sea level, its reliable U-Pb ages and its long timespan, which allows us to quantify uncertainties on potential uplift. Our data indicate that ice sheets are very sensitive to warming and provide important calibration targets for future ice-sheet models7.


Assuntos
Mudança Climática/história , Água do Mar/análise , Calibragem , Dióxido de Carbono/análise , Foraminíferos/química , História Antiga , Camada de Gelo/química , Ilhas , Mar Mediterrâneo , Isótopos de Oxigênio/análise , Espanha , Incerteza
12.
Science ; 365(6457): 1040-1044, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31488692

RESUMO

From June to August 2018, the eruption of Kilauea volcano on the island of Hawai'i injected millions of cubic meters of molten lava into the nutrient-poor waters of the North Pacific Subtropical Gyre. The lava-impacted seawater was characterized by high concentrations of metals and nutrients that stimulated phytoplankton growth, resulting in an extensive plume of chlorophyll a that was detectable by satellite. Chemical and molecular evidence revealed that this biological response hinged on unexpectedly high concentrations of nitrate, despite the negligible quantities of nitrogen in basaltic lava. We hypothesize that the high nitrate was caused by buoyant plumes of nutrient-rich deep waters created by the substantial input of lava into the ocean. This large-scale ocean fertilization was therefore a unique perturbation event that revealed how marine ecosystems respond to exogenous inputs of nutrients.


Assuntos
Fitoplâncton/crescimento & desenvolvimento , Água do Mar/química , Erupções Vulcânicas , Clorofila A/análise , Clorofila A/metabolismo , Eutrofização , Hawaii , Metais/análise , Nitratos/análise , Nitrogênio/análise , Oceano Pacífico , Fitoplâncton/metabolismo , Água do Mar/análise
13.
Environ Pollut ; 254(Pt B): 113082, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31472454

RESUMO

Growing production and consumption of pharmaceuticals is a global problem. Due to insufficient data on the concentration and distribution of pharmaceuticals in the marine environment, there are no appropriate legal regulations concerning their emission. In order to understand all aspects of the fate of pharmaceuticals in the marine environment and their effect on marine biota, it is necessary to find the most appropriate model organism for this purpose. This paper presents an overview of the ecotoxicological studies of pharmaceuticals, regarding the assessment of Mytilidae as suitable organisms for biomonitoring programs and toxicity tests. The use of mussels in the monitoring of pharmaceuticals allows the observation of changes in the concentration and distribution of these compounds. This in turn gives valuable information on the amount of pharmaceutical pollutants released into the environment in different areas. In this context, information necessary for the assessment of risks related to pharmaceuticals in the marine environment are provided based on what effective management procedures can be developed. However, the accumulation capacity of individual Mytilidae species, the bioavailability of pharmaceuticals and their biological effects should be further scrutinized.


Assuntos
Ecotoxicologia/métodos , Mytilidae/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , /métodos , Biota , Ecotoxicologia/instrumentação , Modelos Biológicos , Mytilidae/crescimento & desenvolvimento , Água do Mar/análise , Poluentes Químicos da Água/análise
14.
Mar Pollut Bull ; 146: 1-10, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426133

RESUMO

Urbanization in recent years has driven us to investigate metal contamination on Nellore coast by collecting seawater, sediment, and bivalve samples monthly at five stations from 2015 to 2017. Non-metric multidimensional scaling and cluster analysis indicated that open sea (OS) samples were markedly different from the samples collected at other stations. Strong factor loadings of Al (0.76), Mn (0.79), and Cd (0.78) showed variability in seawater, while those for Fe (0.76), Ni (0.77), Zn (0.85), and Pb (0.81) showed variability in sediment. The mean values of Fe (346 ppm) and Mn (21 ppm) were high in bivalves compared to the mean values of other metals. A higher contamination factor was observed for Cd at Buckingham Canal, while the lowest was observed for sediment in OS. The order of trace metals in sediments according to risk index was Cd > Pb > Cu > Cr > Zn. The results obtained are essential to establish a reference for better comparison of tropical environments.


Assuntos
Bivalves/química , Sedimentos Geológicos/análise , Metais/análise , Água do Mar/análise , Poluentes Químicos da Água/análise , Animais , Ecologia , Monitoramento Ambiental , Índia , Oceanos e Mares , Oligoelementos/análise , Urbanização
15.
Mar Pollut Bull ; 146: 125-133, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426140

RESUMO

We investigated the environmental partitioning and particle characteristics of macro-, meso- and microplastics and their uptake into the mussel, Mytilus edulis. Sediment samples, overlying seawater and mussels from 9 intertidal locations in the South West of England were analysed for abundance and type of microplastic. Micro- and mesoplastic-like particles were found in 88.5% of the 269 mussels sampled, ranging from 1.43 to 7.64 items per mussel. Of these plastic particles, 70.9% were identified as semi-synthetic (mainly modified-cellulose). Mussel microplastic abundance, but not polymer type, was correlated with that of their surrounding sediment, but not with sea-surface microplastic concentration or mussel size for our study sites. We found significant differences in the relative abundance of polymer types and particle sizes between seawater, sediment, and mussels, with mussels over-representing modified-cellulose fibre abundance but under-representing polyvinyl. Mussels contained significantly smaller plastic fragments than their surrounding sediment and shorter fibres than their overlying seawater.


Assuntos
Mytilus edulis/química , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Ecotoxicologia , Inglaterra , Monitoramento Ambiental , Contaminação de Alimentos/análise , Sedimentos Geológicos/análise , Tamanho da Partícula , Plásticos/química , Plásticos/farmacocinética , Água do Mar/análise , Frutos do Mar/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/química , Poluentes Químicos da Água/farmacocinética
16.
Mar Pollut Bull ; 146: 201-205, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426147

RESUMO

In 2018, the Mexican Caribbean coast received a massive influx of pelagic Sargassum spp. that accumulated and decayed on beaches producing organic decomposition products that made the water turbid and brown. Between May and September of the same year there were several reports of mass mortality of marine biota in this area. From these reports we estimate that organisms belonging to 78 faunal species died as result of this event, with demersal neritic fish and Crustacea being the most affected groups. The cause of mortality appears to be the combined effect of high ammonium and hydrogen sulfide concentrations, together with hypoxic conditions. If massive arrival of pelagic Sargassum spp. continues and algae is left to decay on the beach in large volumes then deterioration in water quality could affect coral reefs close to shore. Furthermore, barriers placed in lagoons to intercept the Sargassum spp. before it reaches the beach could impact reef fauna if the algae is left to die and sink on site.


Assuntos
Crustáceos , Peixes , Sargassum/fisiologia , Água do Mar/química , Compostos de Amônio/análise , Animais , Organismos Aquáticos , Região do Caribe , Sulfeto de Hidrogênio/análise , México , Mortalidade , Água do Mar/análise , Qualidade da Água
17.
Mar Pollut Bull ; 146: 22-25, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426150

RESUMO

Here we summarize the overarching issues that emerged from a workshop held to discuss scientific challenges and future directions on the use of numerical models to predict the amount, distribution and effects of plastic pollution on marine ecosystems. The need for multi-disciplinary approaches, standardized protocols for plastic quantification and analyses, using realistic contaminant concentrations in laboratorial experiments and targeting early-life stages of marine organisms were pointed out as needs to improve data accuracy. Participants also enumerated a list of gaps that include, identification of indicator organisms of plastic contamination, selection of biomarkers and the role of extreme events on plastic dynamics. Responding to these gaps will contribute to improve data quantity and quality and, thus, allow developing more reliable models. A crucial role is foreseen for modelling tools as they can incorporate the cumulative impacts of multiple stressors, including the individual-level effects of plastics, to the population- and ecosystem level.


Assuntos
Plásticos/análise , Água do Mar/análise , Poluentes Químicos da Água/análise , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/crescimento & desenvolvimento , Mudança Climática , Ecossistema , Monitoramento Ambiental , Plásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/análise
18.
Mar Pollut Bull ; 146: 377-386, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426170

RESUMO

The effects of nutrient distribution and structure on the behavior and speciation of dissolved inorganic arsenic (DIAs) in coastal waters were analyzed based on the data of 48 surface water samples collected in the southwestern coast of Laizhou Bay and its adjacent rivers (SWLZB). The concentration of DIAs in the SWLZB ranged from 0.016 to 0.099 µmol l-1 and generally decreased from west to south. The inshore waters exhibited higher DIAs level than the open ocean. The As5+/As3+ ratio was significantly positively correlated with the concentration of TDN, NO3-N, PO4-P, DSi, Chl-a and DO. The concentration of DIAs was strongly correlated with the concentration of PO4-P and DSi, suggesting that adsorption/desorption was an important process for regulating the total DIAs concentration. The results indicated that the distribution of nutrients might well be an important environmental factor affecting the speciation and behavior of DIAs in surface water of the SWLZB.


Assuntos
Arsênico/análise , Água do Mar/química , Poluentes Químicos da Água/análise , Arsênico/química , Baías , China , Clorofila A/análise , Monitoramento Ambiental , Concentração de Íons de Hidrogênio , Nitratos/análise , Nitrogênio/análise , Nutrientes/análise , Fosfatos/análise , Fósforo/análise , Rios/química , Água do Mar/análise , Poluentes Químicos da Água/química
19.
Mar Pollut Bull ; 146: 427-434, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426177

RESUMO

To study the impact of rapid industrialization and urbanization in Guangxi Province on the coastal environment in recent years, seven metals (Hg, Cu, Pb, Cd, Cr, Zn and As) were investigated in the surface seawater and sediments of the northern Beibu Gulf. The levels of the metals were lower than in other regions in China, but Hg, Cu and Cd showed a significant increasing trend in both seawater and sediments over the past 20 years. Higher levels were consistently observed in the nearshore area, particularly in the northwest, which may be related to the rapid industrial development in coastal areas. Correlation and principal component analyses suggested that both terrestrial inputs and biological processes influenced the distribution of metals. In addition, the higher risk observed for Hg and Cu may be largely influenced by the increasing trend in these metals in the Beibu Gulf.


Assuntos
Sedimentos Geológicos/análise , Metais Pesados/análise , Água do Mar/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Urbanização
20.
Mar Pollut Bull ; 146: 54-59, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426191

RESUMO

Toxic chemicals within and adsorbed to microplastics (0.05-5 mm) have the potential to biomagnify in food webs. However, microplastic concentrations in highly productive, coastal habitats are not well understood. Therefore, we quantified the presence of microplastics in a benthic community and surrounding environment of a remote marine reserve on the open coast of California, USA. Concentrations of microplastic particles in seawater were 36.59 plastics/L and in sediments were 0.227 ±â€¯0.135 plastics/g. Densities of microplastics on the surfaces of two morphologically distinct species of macroalgae were 2.34 ±â€¯2.19 plastics/g (Pelvetiopsis limitata) and 8.65 ±â€¯6.44 plastics/g (Endocladia muricata). Densities were highest in the herbivorous snail, Tegula funebralis, at 9.91 ±â€¯6.31 plastics/g, potentially due to bioaccumulation. This study highlights the need for further investigations of the prevalence and potential harm of microplastics in benthic communities at remote locations as well as human population centers.


Assuntos
Gastrópodes/química , Plásticos/análise , Água do Mar/análise , Alga Marinha/química , Caramujos/química , Animais , California , Ecossistema , Monitoramento Ambiental , Cadeia Alimentar , Gastrópodes/metabolismo , Sedimentos Geológicos/análise , Humanos , Plásticos/metabolismo , Alga Marinha/metabolismo , Caramujos/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
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