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Registros recuperados: 105 | |
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Muresan, B; Cossa, Daniel; Coquery, M; Richard, S. |
The distribution, partition and speciation of mercury (Hg) were studied along the redox gradient of an anthropogenically perturbed tropical estuary, the Sinnamary Estuary in French Guiana. This system is a partially mixed estuary characterized by an anoxic freshwater end-member, while the marine end member consists of the Amazon Plume. The set up of an artificial oxygenation system in the anoxic freshwater end-member generates sharp gradients of major chemical species (iron, sulfides, etc.) coupled with intense organic matter (OM) turnover. The coexistence of oxygenated waters and dissolved sulfides in an organic rich environment depicts the Upper Sinnamary Estuary (USE: part of Sinnamary Estuary under the tidal influence but upstream of the salt... |
Tipo: Text |
Palavras-chave: Partitioning; Speciation; Redox; Mercury; Reservoir; Estuary. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4223.pdf |
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Zu Ermgassen, Philine S. E.; Bonačić, Kruno; Boudry, Pierre; Bromley, Cass A.; Cameron, Tom C.; Colsoul, Bérenger; Coolen, Joop W. P.; Frankić, Anamarija; Hancock, Boze; Have, Tom M.; Holbrook, Zoë; Kamermans, Pauline; Laugen, Ane T.; Nevejan, Nancy; Pogoda, Bernadette; Pouvreau, Stephane; Preston, Joanne; Ranger, Christopher J.; Sanderson, William G.; Sas, Hein; Strand, Åsa; Sutherland, William J.. |
Oyster reefs are among the most threatened marine habitats globally. In Europe, oyster reefs have been extirpated from most locations within their historical range. Active restoration of the native oyster (Ostrea edulis) in Europe has grown substantially in recent years. In sharing experiences between oyster restoration projects in Europe at the Native Oyster Restoration Alliance conference, NORA2, in Edinburgh in May 2019, it became apparent that a number of similar barriers are experienced. This study identified the top 40 questions, which, if answered, would have the greatest influence on the policy and practice of oyster restoration in Europe. Initially 71 people were consulted across 28 institutions and 11 European countries to generate 194 questions.... |
Tipo: Text |
Palavras-chave: Alien species; Estuary; Fishing; Invertebrates; Pollution; Restoration; Subtidal. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/77004/78261.pdf |
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Caquet, Th.; Roucaute, M.; Mazzella, N.; Delmas, F.; Madigou, C.; Farcy, E.; Burgeot, Thierry; Allenou, Jean-pierre; Gabellec, Raoul. |
A 2-year study was implemented to characterize the contamination of estuarine continuums in the Bay of Vilaine area (NW Atlantic Coast, Southern Brittany, France) by 30 pesticide and biocide active substances and metabolites. Among these, 11 triazines (ametryn, atrazine, desethylatrazine, desethylterbuthylazine, desisopropyl atrazine, Irgarol 1051, prometryn, propazine, simazine, terbuthylazine, and terbutryn), 10 phenylureas (chlortoluron, diuron, 1-(3,4-dichlorophenyl)-3-methylurea, fenuron, isoproturon, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl)-urea, linuron, metoxuron, and monuron), and 4 chloroacetanilides (acetochlor, alachlor, metolachlor, and metazachlor) were detected at least once. The objectives were to assess the corresponding... |
Tipo: Text |
Palavras-chave: Estuary; Herbicides; Booster biocides; Species sensitivity distribution; Risk quotient; AtlanticCoast. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00124/23571/22554.pdf |
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Cabecadas, L. |
Biomass and phytoplankton photosynthetic response were studied in the lower Tagus estuary weekly, and related to environmental conditions in February, March and April 1994. The Photosynthesis-Irradiance ((P-I)-I-B) relation was studied based on the light-saturated photosynthesis rate (P(B)m) and the light-limited initial slope (a(B)). The nutrient concentrations observed were high enough to be considered as not limiting phytoplankton growth. Tagus estuary phytoplankton seems, to a certain extent, adapted to high turbid conditions, being able to utilize the low light levels more efficiently, which was translated by high values of a(B) [0.10-0.20 mg C (mg Chl a)(-1) h(-1) (W m(-2))(-1)]; however, light seems to limit phytoplankton production in the water... |
Tipo: Text |
Palavras-chave: Production primaire; Phytoplancton; Estuaire; Biomasse; Turbidité; Primary production; Phytoplankton; Estuary; Biomass; Turbidity. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43621/43310.pdf |
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Dauer, Dm. |
Long-term trends in subtidal macrobenthic communities of the lower Chesapeake Bay, USA, were examined using data collected quarterly (March, June, September and December) fr om 1985 through 1993 at 16 stations along a salinity gradient from tidal freshwater regions of the major tributaries (James, York and Rappahannock rivers) to the polyhaline region of the mainstem of Chesapeake Bay. In March 1989 two stations were added to the program in the mesohaline region of the Southern Branch of the Elizabeth River, a region characterized by contaminated sediments. A non-parametric trend analysis procedure was applied to five parameters characterizing macrobenthic community structure: community biomass, species richness, abundance of individuals, proportion of... |
Tipo: Text |
Palavras-chave: Chesapeake Bay; Benthos; Trends; Estuary; Eutrophication. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20399/18066.pdf |
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Bharathi, Pal; Oak, S; Chandramohan, D. |
Sulfate-reducing bacteria (SRB) have been enumerated and physiologically characterized in three mangrove stations along the Zuari estuary. The substrates for counting were lactate, acetate, propionate, butyrate and benzoate. Benzoate oxidizing SRB were widespread and occurred in numbers up to 6.62 x 10(3)/g dry sediment. The next highest in number were lactate utilizing SRB. On an average there were more propionate and butyrate utilizers than acetate utilizers. While Agasaim at the mouth of the estuary harboured highest number of lactate oxidizers, none were detected at Mirabaug upstream during the samplings. The SRB shared many characteristics with Desulfovibrio desulfuricans, D. desulfuricans aestuarii, D. salexigens, Desulfotomaculum orientis, D.... |
Tipo: Text |
Palavras-chave: Bactéries; Sulfato-réductrices; Estuaire; Sédiments; Mangrove; Mangrove-Bacteria; Sulfate-reducers; Estuary; Sediments. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00323/43395/43103.pdf |
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Guesdon, Stephane; Stachowski-haberkorn, Sabine; Lambert, Christophe; Beker, Beatriz; Brach-papa, Christophe; Auger, Dominique; Bechemin, Christian. |
This study aimed to describe seasonal variations of phytoplankton abundances in relation to the physical and chemical (nutrients and metals) environment under the influence of freshwater input in the Charente river estuary (Marennes-Oléron bay, France) over three years, from 2011 to 2014. Phytoplankton abundances were determined using microscopy and flow cytometry. Considering high frequency temperature and salinity data, breakpoints in each series led to the identification of two local hydroclimatic periods: the first (2011 and early 2012) being warmer and higher in salinity than the second (from spring 2012 to the beginning of 2014). A multiblock PLS analysis highlighted the significant contribution of the physical environment (temperature, salinity and... |
Tipo: Text |
Palavras-chave: Hydroclimate; Estuary; Phytoplankton; Size composition; Nutrients; Trace metals. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00349/46005/45674.pdf |
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Lanceleur, Laurent; Schaefer, Joerg; Chiffoleau, Jean-francois; Blanc, Gerard; Auger, Dominique; Renault, Sophie; Baudrimont, Magalie; Audry, Stephane. |
The Gironde fluvial estuarine system is impacted by historic metal pollution (e.g. Cd, Zn, Hg) and oysters (Crassostrea gigas) from the estuary mouth have shown extremely high Cd concentrations for decades. Based on recent work (Chiffoleau et al., 2005) revealing anomalously high Ag concentrations (up to 65 mg kg(-1); dry weight) in Gironde oysters, we compared long-term (similar to 1955-2001) records of Ag and Cd concentrations in reservoir sediment with the respective concentrations in oysters collected between 1979 and 2010 to identify the origin and historical trend of the recently discovered Ag anomaly. Sediment cores from two reservoirs upstream and downstream from the main metal pollution source provided information on (i) geochemical background... |
Tipo: Text |
Palavras-chave: Silver; Cadmium; Estuary; Oyster; Biomonitoring. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00060/17109/15071.pdf |
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Goni-urriza, M. S.; Point, D.; Amouroux, D.; Guyoneaud, R.; Donard, O. F. X.; Caumette, P.; Duran, R.. |
Salinity, other physico-chemical parameters and anthropogenic pollution are the main factors affecting bacterial communities in estuaries. We estimated the impact of these parameters on the distribution of bacterial communities in the Adour estuary (France), a moderately Polluted water body characterized by short residence times of particles and water and absence of a maximum turbidity zone. Eight stations were established along the salinity gradient from freshwater to marine conditions. For the 3 typical estuarine stations (water mixing zone), samples were collected at both low and high tide and at different depths according to the position of the halocline. This sampling strategy generated 35 samples with different degrees of mixing between fresh water... |
Tipo: Text |
Palavras-chave: Bacterial communities; Salinity gradient; Heavy metals; Estuary; Halocline; T-RFLP. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00249/35983/34517.pdf |
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Couton, Marjorie; Comtet, Thierry; Le Cam, Sabrina; Corre, Erwan; Viard, Frédérique. |
High-throughput sequencing (HTS) technologies offer new promise to support surveillance programs targeting marine non-indigenous species (NIS). Metabarcoding might surpass traditional monitoring methods, for example through its ability to detect rare species, a key feature in early detection of NIS. Another interest of this approach is the identification of organisms difficult to identify based on morphology only (e.g., early developmental stages), making it relevant in the context of management programs. Because many marine benthic NIS have a biphasic benthopelagic life cycle, targeting their pelagic larval stages in zooplankton may allow early detection and assessment of their establishment and potential spread. We illustrate this approach with an... |
Tipo: Text |
Palavras-chave: Zooplankton; Time-series; Non-indigenous species; Estuary; High-throughput sequencing; Surveillance; Monitoring. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00599/71127/69442.pdf |
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Ribeiro, Lourenço; Le Bris, Anthony; Hernandez Farinas, Tania; Buchet, Remi; Dutertre, Mickaël; Metzger, Edouard; Rosa, Philippe; Gernez, Pierre; Lerouxel, Astrid; Barille, Laurent. |
In order to establish the ecological status of water bodies, the European Water Framework Directive (WFD) is based on the evaluation of a number of biological quality elements, as well as physical parameters supporting the biology. In estuaries, phytoplankton monitoring was not considered relevant because of the high turbidity characterizing the large metropolitan estuaries and the French overseas departments (Guyana). In this work, we considered the possibility of using microphytobenthos (MPB) as a biological indicator of the ecological status of estuaries. This activity report summarizes the actions undertaken in 2017 under an AFB / Université de Nantes convention, which is structured around two main axes: the first axis is based on the analysis of the... |
Tipo: Text |
Palavras-chave: DCE; Diatomées benthiques; Diversité; Estuaires; Facteurs naturels; Gradient de perturbation; Loire; Bio-indication; Microphytobenthos; Pressions anthropiques; Télédétection.; Anthropogenic pressures; Benthic diatoms; Bio-indication; Diversity; Estuary; Loire; Microphytobenthos; Natural factors; Perturbation gradient; Remote sensing; WFD. |
Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00446/55725/57376.pdf |
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Lavaud, Romain; La Peyre, Megan K.; Casas, Sandra M.; Bacher, Cedric; La Peyre, Jerome F.. |
We present a Dynamic Energy Budget (DEB) model for the eastern oyster, Crassostrea virginica, which enables the inclusion of salinity as a third environmental variable, on top of the standard foodr and temperature variables. Salinity changes have various effects on the physiology of oysters, potentially altering filtration and respiration rates, and ultimately impacting growth, reproduction and mortality. We tested different hypotheses as to how to include these effects in a DEB model for C. virginica. Specifically, we tested two potential mechanisms to explain changes in oyster shell growth (cm), tissue dry weight (g) and gonad dry weight (g) when salinity moves away from the ideal range: 1) a negative effect on filtration rate and 2) an additional... |
Tipo: Text |
Palavras-chave: DEB theory; Bioenergetics; Filtration; Maintenance; Growth; Estuary; Louisiana. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00400/51137/53773.pdf |
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Allen, G.; D'Ozouville, Laurent; L'Yavanc, Jacky. |
The Aber Benoît, a small estuary on the North West coast of Brittany was polluted by oil from the Amoco Cadiz oil spill. Preliminary results from water and sediment samples taken in the estuary in May 1978, show that two months after the initial spill, high concentrations of hydrocarbures existed in the water and sediments of the estuary. The Aber Benoît shows a well developed salt wedge and upstream increasing suspended sediment concentrations. Oil was dispersed more or less evenly throughout the water column, in the entire length of the estuary. In the bottom sediments, oil had accumulated to depths of 30 cm. Sand bars appear to induce a trapping of oil in the estuary channel. |
Tipo: Text |
Palavras-chave: Estuaire; Sédiment; Pollution Hydrocarbures; Estuary; Sediment; Oil spill. |
Ano: 1978 |
URL: http://archimer.ifremer.fr/doc/00306/41721/40932.pdf |
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Cabrita, Mt; Catarino, F; Vale, C. |
The time-course evolution of ammonium concentration has been examined in the flood water during the first 25 min of tidal inundation. The way this transport fluctuates with the tidal ranges and wind conditions was investigated. Flood water was collected at three sites, located along a transect from the lower to the upper intertidal area of the Tagus estuary. At spring and intermediate tides, the periods of air exposure vary slightly along the transect due to the high tidal amplitude and the flatness of the area, but the upper site remains uncovered at neap tide over the entire tidal cycle. At each site, sampling was performed at different tidal ranges covering the neap-spring tidal cycle and wind conditions. Ammonium was determined in the flood water at... |
Tipo: Text |
Palavras-chave: Extraction par la marée; Ammonium; Sédiment intertidal; Estuaire; Tidal flushing; Ammonium; Intertidal sediments; Estuary. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43611/43908.pdf |
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Registros recuperados: 105 | |
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