خيارات البحث
النتائج 911 - 920 من 1,966
Microbiological composition of native and exotic clams from Tagus estuary: Effect of season and environmental parameters النص الكامل
2013
Anacleto, Patrícia | Pedro, Sónia | Nunes, Maria Leonor | Rosa, Rui | Marques, António
The influence of seasonal and environmental parameters on the occurrence of bacteria was investigated in two clam species (Venerupis pullastra and Ruditapes philippinarum), water and sediment from the Tagus estuary. Total viable counts (TVC), Escherichia coli, Salmonella spp. and Vibrio spp. were evaluated during one-year. Overall, significant seasonal variations were found in both sampling sites, especially for E. coli and Vibrio spp. levels. In summer, significantly higher Vibrio spp. levels were found in R. philippinarum and sediment samples, but not in V. pullastra clams and water samples. In contrast, significantly higher TVC and E. coli levels were observed in winter months in water and sediment samples. Salmonella spp. was generally isolated when higher levels of E. coli were detected, particularly in R. philippinarum. This study is useful for authorities to develop monitoring strategies for coastal contamination and to estimate human health risks associated with the consumption of bivalves.
اظهر المزيد [+] اقل [-]Effects of elevated pCO2 on reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica النص الكامل
2013
Effects of elevated pCO2 on reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica النص الكامل
2013
We investigated the effects of elevated pCO2 in seawater both on the acute mortality and the reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica with the purpose of accumulating basic data for assessing potential environmental impacts of sub-sea geological storage of anthropogenic CO2 in Japan. Acute tests showed that nauplii of T. japonicus have a high tolerance to elevated pCO2 environments. Full life cycle tests on T. japonicus indicated NOEC=5800μatm and LOEC=37,000μatm. Adult B. japonica showed remarkable resistance to elevated pCO2 in the acute tests. Embryonic development of B. japonica showed a NOEC=1500μatm and LOEC=5400μatm. T. japonicus showed high resistance to elevated pCO2 throughout the life cycle and B. japonica are rather sensitive during the veliger stage when they started to form their shells.
اظهر المزيد [+] اقل [-]Seawater carbonate chemistry and reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica in a laboratory experiment النص الكامل
2013
Kita, Jun | Kikkawa, Takashi | Asai, Takamasa | Ishimatsu, Atsushi
We investigated the effects of elevated pCO2 in seawater both on the acute mortality and the reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica with the purpose of accumulating basic data for assessing potential environmental impacts of sub-sea geological storage of anthropogenic CO2 in Japan. Acute tests showed that nauplii of T. japonicus have a high tolerance to elevated pCO2 environments. Full life cycle tests on T. japonicus indicated NOEC = 5800 µatm and LOEC = 37,000 µatm. Adult B. japonica showed remarkable resistance to elevated pCO2 in the acute tests. Embryonic development of B. japonica showed a NOEC = 1500 µatm and LOEC = 5400 µatm. T. japonicus showed high resistance to elevated pCO2 throughout the life cycle and B. japonica are rather sensitive during the veliger stage when they started to form their shells.
اظهر المزيد [+] اقل [-]Climate change and the oceans – What does the future hold? النص الكامل
2013
Bijma, Jelle | Pörtner, Hans-O. | Yesson, Chris | Rogers, Alex D.
Climate change and the oceans – What does the future hold? النص الكامل
2013
Bijma, Jelle | Pörtner, Hans-O. | Yesson, Chris | Rogers, Alex D.
The ocean has been shielding the earth from the worst effects of rapid climate change by absorbing excess carbon dioxide from the atmosphere. This absorption of CO2 is driving the ocean along the pH gradient towards more acidic conditions. At the same time ocean warming is having pronounced impacts on the composition, structure and functions of marine ecosystems. Warming, freshening (in some areas) and associated stratification are driving a trend in ocean deoxygenation, which is being enhanced in parts of the coastal zone by upwelling of hypoxic deep water. The combined impact of warming, acidification and deoxygenation are already having a dramatic effect on the flora and fauna of the oceans with significant changes in distribution of populations, and decline of sensitive species. In many cases, the impacts of warming, acidification and deoxygenation are increased by the effects of other human impacts, such as pollution, eutrophication and overfishing.The interactive effects of this deadly trio mirrors similar events in the Earth’s past, which were often coupled with extinctions of major species’ groups. Here we review the observed impacts and, using past episodes in the Earth’s history, set out what the future may hold if carbon emissions and climate change are not significantly reduced with more or less immediate effect.
اظهر المزيد [+] اقل [-]Climate change and the oceans - What does the future hold? النص الكامل
2013
Bijma, Jelle | Pörtner, Hans-Otto | Yesson, Chris | Rogers, A. D.
Recent innovation in microbial source tracking using bacterial real-time PCR markers in shellfish النص الكامل
2013
Mauffret, A. | Mieszkin, S. | Morizur, M. | Alfiansah, Y. | Lozach, S. | Gourmelon, M.
Recent innovation in microbial source tracking using bacterial real-time PCR markers in shellfish النص الكامل
2013
Mauffret, A. | Mieszkin, S. | Morizur, M. | Alfiansah, Y. | Lozach, S. | Gourmelon, M.
We assessed the capacity of real-time PCR markers to identify the origin of contamination in shellfish. Oyster, cockles or clams were either contaminated with fecal materials and host-associated markers designed from Bacteroidales or Catellicoccus marimammalium 16S RNA genes were extracted from their intravalvular liquid, digestive tissues or shellfish flesh. Extraction of bacterial DNA from the oyster intravalvular liquid with FastDNA spin kit for soil enabled the selected markers to be quantified in 100% of artificially contaminated samples, and the source of contamination to be identified in 13 out of 38 naturally contaminated batches from European Class B and Class C areas. However, this protocol did not enable the origin of the contamination to be identified in cockle or clam samples. Although results are promising for extracts from intravalvular liquid in oyster, it is unlikely that a single protocol could be the best across all bacterial markers and types of shellfish.
اظهر المزيد [+] اقل [-]Recent innovation in microbial source tracking using bacterial real-time PCR markers in shellfish النص الكامل
2013
Mauffret, Aourell | Mieszkin, Sophie | Morizur, Mael | Alfiansah, Yustian Rovi | Lozach, Solen | Gourmelon, Michele
We assessed the capacity of real-time PCR markers to identify the origin of contamination in shellfish. Oyster, cockles or clams were either contaminated with fecal materials and host-associated markers designed from Bacteroidales or Catellicoccus marimammalium 16S RNA genes were extracted from their intravalvular liquid, digestive tissues or shellfish flesh. Extraction of bacterial DNA from the oyster intravalvular liquid with FastDNA spin kit for soil enabled the selected markers to be quantified in 100% of artificially contaminated samples, and the source of contamination to be identified in 13 out of 38 naturally contaminated batches from European Class B and Class C areas. However, this protocol did not enable the origin of the contamination to be identified in cockle or clam samples. Although results are promising for extracts from intravalvular liquid in oyster, it is unlikely that a single protocol could be the best across all bacterial markers and types of shellfish. (C) 2013 Elsevier Ltd. All rights reserved.
اظهر المزيد [+] اقل [-]Consistent assessment of trace metal contamination in surface sediments and suspended particulate matter: A case study from the Jade Bay in NW Germany النص الكامل
2013
Beck, Melanie | Böning, Philipp | Schückel, Ulrike | Stiehl, Thorsten | Schnetger, Bernhard | Rullkötter, J. | Brumsack, Hans-Jürgen
Consistent assessment of trace metal contamination in surface sediments and suspended particulate matter: A case study from the Jade Bay in NW Germany النص الكامل
2013
Beck, Melanie | Böning, Philipp | Schückel, Ulrike | Stiehl, Thorsten | Schnetger, Bernhard | Rullkötter, J. | Brumsack, Hans-Jürgen
Recently, within the framework of European directives, the importance of marine monitoring programs has increased. In this study, a dense sampling grid was applied for a detailed assessment of the metal contents of surface sediments and suspended particulate matter from the Jade Bay, one of the tidal basins in the southern North Sea. The local lithogenic background was defined and compared with average shale, a common reference material. Based on the calculated non-lithogenic fraction and a cluster analysis, the metals are distributed in two groups: (i) elements of mainly natural origin (Co, Cr, and a major portion of Cd) and (ii) elements associated with anthropogenic activity (As, Cd, Cu, Ni, Pb, Sn, and Zn). However, even the metals of the second group are enriched by at most a factor of two relative to the local background, suggesting minimal anthropogenic impact. Spatial distribution maps show that the harbor area of Wilhelmshaven may be a particularly important source of metal.
اظهر المزيد [+] اقل [-](Table S-6) Suspended particulate matter data of the North Sea النص الكامل
Neuholz, René | Schnetger, Bernhard | Ahrens, Janis | Beck, Melanie | Böning, Philipp | Burt, William J | Dellwig, Olaf | Kossack, Michael | Mori, Corinna | Wrede, Alexa | Brumsack, Hans-Jürgen
Effects of anthropogenic metallic contamination on cholinesterases of Gambusia holbrooki النص الكامل
2013
Brandão, Fátima | Correia, Alberto Teodorico | Gonçalves, Fernando | Nunes, Bruno
Effects of anthropogenic metallic contamination on cholinesterases of Gambusia holbrooki النص الكامل
2013
Brandão, Fátima | Correia, Alberto Teodorico | Gonçalves, Fernando | Nunes, Bruno
Metal contamination causes multiple biological dysfunctions, including impairment of key physiological functions by targeting enzymes. This feature is a matter of concern, since it may imply significant disturbances in energy allocation, behaviour, reproduction, and survival. Inhibition of the cholinesterase (ChE) activity of aquatic organisms by metals has been described, and systematically used in biomonitoring studies as effect criterion of environmental exposure to these compounds. The present paper addresses the feasibility of using ChE inhibition to quantify the adverse acute and chronic effects of metals (copper, zinc, lead, and cadmium) on nervous tissue of Gambusia holbrooki. With the exception of acute exposure to copper, ChE activity was not significantly impaired. The meanings of the reported findings are further discussed, aiming at a more comprehensive use of this biomarker in environmental assessment. Based on the obtained results, the role of ChE inhibition in environmental metal contamination scenarios should be questioned or even discarded.
اظهر المزيد [+] اقل [-]Effects of anthropogenic metallic contamination on cholinesterases of Gambusia holbrooki النص الكامل
2013
Brandão, Fátima | Correia, Alberto Teodorico | Gonçalves, Fernando | Nunes, Bruno
Metal contamination causes multiple biological dysfunctions, including impairment of key physiological functions by targeting enzymes. This feature is a matter of concern, since it may imply significant disturbances in energy allocation, behaviour, reproduction, and survival. Inhibition of the cholinesterase (ChE) activity of aquatic organisms by metals has been described, and systematically used in biomonitoring studies as effect criterion of environmental exposure to these compounds. The present paper addresses the feasibility of using ChE inhibition to quantify the adverse acute and chronic effects of metals (copper, zinc, lead, and cadmium) on nervous tissue of Gambusia holbrooki. With the exception of acute exposure to copper, ChE activity was not significantly impaired. The meanings of the reported findings are further discussed, aiming at a more comprehensive use of this biomarker in environmental assessment. Based on the obtained results, the role of ChE inhibition in environmental metal contamination scenarios should be questioned or even discarded. | The present work was funded by Fundação para a Ciência e a Tecnologia: project “BiOtoMetal” (PTDC/AMB/70431/2006). We would like to acknowledge the contribution of Jonathan Wilson, for his decisive contribution to the final format of this article. | published
اظهر المزيد [+] اقل [-]Environmental harm assessment of a wastewater discharge from Hammerfest LNG: A study with biomarkers in mussels (Mytilus sp.) and Atlantic cod (Gadus morhua) النص الكامل
2013
Beyer, Jonny | Aarab, Nadia | Tandberg, Anne Helene | Ingvarsdottir, Anna | Bamber, Shaw | Børseth, Jan Fredrik | Camus, Lionel | Velvin, Roger
Environmental harm assessment of a wastewater discharge from Hammerfest LNG: A study with biomarkers in mussels (Mytilus sp.) and Atlantic cod (Gadus morhua) النص الكامل
2013
Beyer, Jonny | Aarab, Nadia | Tandberg, Anne Helene | Ingvarsdottir, Anna | Bamber, Shaw | Børseth, Jan Fredrik | Camus, Lionel | Velvin, Roger
Biologically treated wastewater (WW) from the Hammerfest LNG (liquefied natural gas) plant is discharged to the sea. A study using biomarkers in mussels and Atlantic cod was performed to examine whether this discharge meets a zero harmful emission requirement. Caging of mussels close to the outfall and exposure of mussels and fish to WW in the laboratory were conducted, and a suite of contaminant responsive markers was assessed in exposed animals. In mussels the markers included chemical contaminant levels, haemocyte lysosomal instability and nucleus integrity, cellular energy allocation, digestive gland and gonad histopathology and shell-opening behaviour. In fish, biliary PAH metabolites and gill histopathology biomarkers were measured. A consistent cause-effect relationship between WW treatments and markers measured in test animals was not found. The results therefore indicate that the WW emission is unlikely to represent a significant stress factor for the local marine environment under the conditions studied.
اظهر المزيد [+] اقل [-]Environmental harm assessment of a wastewater discharge from Hammerfest LNG: A study with biomarkers in mussels (Mytilus sp.) and Atlantic cod (Gadus morhua) النص الكامل
2013
Beyer, Jonny | Aarab, Nadia | Tandberg, Anne Helene Solberg | Ingvarsdottir, Anna | Bamber, Shaw Duncan | Børseth, Jan Fredrik | Camus, Lionel | Velvin, Roger
Biologically treated wastewater (WW) from the Hammerfest LNG (liquefied natural gas) plant is discharged to the sea. A study using biomarkers in mussels and Atlantic cod was performed to examine whether this discharge meets a zero harmful emission requirement. Caging of mussels close to the outfall and exposure of mussels and fish to WW in the laboratory were conducted, and a suite of contaminant responsive markers was assessed in exposed animals. In mussels the markers included chemical contaminant levels, haemocyte lysosomal instability and nucleus integrity, cellular energy allocation, digestive gland and gonad histopathology and shell-opening behaviour. In fish, biliary PAH metabolites and gill histopathology biomarkers were measured. A consistent cause-effect relationship between WW treatments and markers measured in test animals was not found. The results therefore indicate that the WW emission is unlikely to represent a significant stress factor for the local marine environment under the conditions studied. | acceptedVersion
اظهر المزيد [+] اقل [-]Habitat degradation correlates with tolerance to climate-change related stressors in the green mussel Perna viridis from West Java, Indonesia النص الكامل
2013
Wendling, Carolin Charlotte | Huhn, Mareike | Ayu, Nurina | Bachtiar, Ramadian | Juterzenka, Karen von | Lenz, Mark
Habitat degradation correlates with tolerance to climate-change related stressors in the green mussel Perna viridis from West Java, Indonesia النص الكامل
2013
Wendling, Carolin Charlotte | Huhn, Mareike | Ayu, Nurina | Bachtiar, Ramadian | Juterzenka, Karen von | Lenz, Mark
It is unclear whether habitat degradation correlates with tolerance of marine invertebrates to abiotic stress. We therefore tested whether resistance to climate change-related stressors differs between populations of the green mussel Perna viridis from a heavily impacted and a mostly pristine site in West Java, Indonesia. In laboratory experiments, we compared their oxygen consumption and mortality under lowered salinity (−13 and −18 units, both responses), hypoxia (0.5mg/l, mortality only) and thermal stress (+7°C, mortality only). Mussels from the eutrophied and polluted Jakarta Bay showed a significantly smaller deviation from their normal oxygen consumption and higher survival rates when stressed than their conspecifics from the unaffected Lada Bay. This shows that human induced habitat degradation correlates with mussel tolerance to environmental stress. We discuss possible mechanisms – e.g. the selection of tolerant genotypes or habitat-specific differences in the nutritional status of the mussels – that could explain our observation.
اظهر المزيد [+] اقل [-]Habitat degradation correlates with tolerance to climate-change related stressors in the green mussel Perna viridis from West Java, Indonesia
2013
Wendling, Carolin | Huhn, Mareike | Nurina, Ayu | Bactiar, Ramadian | von Juterzenka, Karen | Lenz, Mark
It is unclear whether habitat degradation correlates with tolerance of marine invertebrates to abiotic stress. We therefore tested whether resistance to climate change-related stressors differs between populations of the green mussel Perna viridis from a heavily impacted and a mostly pristine site in West Java, Indonesia. In laboratory experiments, we compared their oxygen consumption and mortality under lowered salinity (�13 and �18 units, both responses), hypoxia (0.5 mg/l, mortality only) and thermal stress (+7 �C, mortality only). Mussels from the eutrophied and polluted Jakarta Bay showed a significantly smaller deviation from their normal oxygen consumption and higher survival rates when stressed than their conspecifics from the unaffected Lada Bay. This shows that human induced habitat degradation correlates with mussel tolerance to environmental stress. We discuss possible mechanisms – e.g. the selection of tolerant genotypes or habitat-specific differences in the nutritional status of the mussels – that could explain our observation.
اظهر المزيد [+] اقل [-]Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal) النص الكامل
2013
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D’Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses | Pardal, Miguel Ângelo
Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal) النص الكامل
2013
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D’Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses | Pardal, Miguel Ângelo
The main objective of this paper was to evaluate the impact of mercury on the zooplankton communities’ structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover, the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.
اظهر المزيد [+] اقل [-]Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal) النص الكامل
1000
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D'Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses Miranda | Pardal, Miguel Ângelo
The main objective of this paper was to evaluate the impact of mercury on the zooplankton communities' structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover, the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.
اظهر المزيد [+] اقل [-]A meta-analysis approach to the effects of fish farming on soft bottom polychaeta assemblages in temperate regions النص الكامل
2013
Martínez García, Elena | Sanchez-Jerez, Pablo | Aguado-Giménez, Felipe | Ávila, Pablo | Guerrero, Alejandro | Sánchez Lizaso, José Luis | Fernandez-Gonzalez, Victoria | González, Nieves | Gairin, Joan Ignasi | Carballeira, Carlos | García-García, Benjamín | Carreras, Jordi | Macías, Jose Carlos | Carballeira, Alejo | Collado, Cayetano
A meta-analysis approach to the effects of fish farming on soft bottom polychaeta assemblages in temperate regions النص الكامل
2013
Martínez García, Elena | Sanchez-Jerez, Pablo | Aguado-Giménez, Felipe | Ávila, Pablo | Guerrero, Alejandro | Sánchez Lizaso, José Luis | Fernandez-Gonzalez, Victoria | González, Nieves | Gairin, Joan Ignasi | Carballeira, Carlos | García-García, Benjamín | Carreras, Jordi | Macías, Jose Carlos | Carballeira, Alejo | Collado, Cayetano
Marine fish farms could cause environmental disturbances on the sediment due to uneaten food and fish faeces that impact the marine benthos. Polychaete assemblages are considered good indicators of environmental perturbations. The present study aimed to establish groups of polychaetes as potential indicators of fish farm pollution. This study was carried out in ten fish farms along the Spanish coast. Changes in polychaete assemblage were analyzed with meta-analysis and multivariate techniques. Abundance, richness and diversity showed significant decreases under fish farm conditions. Distribution patterns of polychaetes responded to combinations of physicochemical variables. The main ones are sulfide concentration, silt and clays percentage, and stable nitrogen isotope ratio. The results showed that some families are tolerant, Capitellidae, Dorvilleidae, Glyceridae, Nereididae, Oweniidae and Spionidae; while others are sensitive to fish farm pollution, Magelonidae, Maldanidae, Nephtyidae, Onuphidae, Paralacydoniidae, Paraonide, Sabellidae and also Cirratulidae in spite of being reported as a tolerant family.
اظهر المزيد [+] اقل [-]A meta-analysis approach to the effects of fish farming on soft bottom polychaeta assemblages in temperate regions النص الكامل
2013
Martinez-Garcia, Elena | Sanchez-Jerez, Pablo | Aguado Giménez, Felipe | Ávila, Pablo | Guerrero, Alejandro | Sánchez-Lizaso, José Luis | Fernandez-Gonzalez, Victoria | González, Nieves | Gairin Deulofeu, Joan Ignasi | Carballeira, Carlos | García García, Benjamín | Carreras, Jordi | Macías, José Carlos | Carballeira, Alejo | Collado, Cayetano | Fernandez-Gonzalez, Victoria | Sanchez-Jerez, Pablo | Sánchez-Lizaso, José Luis | Universidad de Alicante. Departamento de Ciencias del Mar y Biología Aplicada | Biología Marina | Recursos Hídricos y Desarrollo Sostenible
Marine fish farms could cause environmental disturbances on the sediment due to uneaten food and fish faeces that impact the marine benthos. Polychaete assemblages are considered good indicators of environmental perturbations. The present study aimed to establish groups of polychaetes as potential indicators of fish farm pollution. This study was carried out in ten fish farms along the Spanish coast. Changes in polychaete assemblage were analyzed with meta-analysis and multivariate techniques. Abundance, richness and diversity showed significant decreases under fish farm conditions. Distribution patterns of polychaetes responded to combinations of physicochemical variables. The main ones are sulfide concentration, silt and clays percentage, and stable nitrogen isotope ratio. The results showed that some families are tolerant, Capitellidae, Dorvilleidae, Glyceridae, Nereididae, Oweniidae and Spionidae; while others are sensitive to fish farm pollution, Magelonidae, Maldanidae, Nephtyidae, Onuphidae, Paralacydoniidae, Paraonide, Sabellidae and also Cirratulidae in spite of being reported as a tolerant family. | This study is part of the project “Selección de indicadores, determinación de valores de referencia, diseño de programas y protocolos de métodos y medidas para estudios ambientales en acuicultura marina” and was funded by the “Spanish National Plans of Aquaculture” (JACUMAR).
اظهر المزيد [+] اقل [-]