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Registros recuperados: 165 | |
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Jones, Krista L; Institute of Ecology, University of Georgia; kjones@eco-metrics.com; Poole, Geoffrey C; Eco-metrics, Inc. and Institute of Ecology, University of Georgia; gpoole@eco-metrics.com; Meyer, Judy L; Institute of Ecology, University of Georgia; jlmeyer@uga.edu; Bumback, William; River Basin Center, University of Georgia; wbumback@uga.edu; Kramer, Elizabeth A; Natural Resources Spatial Analysis Laboratory, University of Georgia; lkramer@uga.edu. |
Regulations governing the management of streamside vegetation (riparian buffers) lie at a nexus between environmental, social, and land development interests, and can yield especially contentious debates among stakeholders. In 2001, the State Legislature of Georgia, USA, took up this debate; the Legislature reduced the minimum width of mandatory-forested riparian buffers along designated trout streams from ∼30 m (100 ft) to ∼15 m (50 ft), and commissioned this study to assess the expected response of existing trout populations. Because our research was designed to provide rigorous and accessible data for informing this management debate, this research may serve as a general template for other studies designed to inform regulatory and... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Georgia; Natural resource legislation; Riparian buffer width; Scientific assessment; Sediment; Southern Appalachians; Stream temperature; Trout. |
Ano: 2006 |
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Goatley, Christopher H. R.; College of Marine and Environmental Sciences, James Cook University; Australian Research Council Centre of Excellence for Coral Reef Studies; christopher.goatley@jcu.edu.au; Fox, Rebecca J.; College of Marine and Environmental Sciences, James Cook University; Australian Research Council Centre of Excellence for Coral Reef Studies; Division of Evolution, Ecology and Genetics, Australian National University; School of Life Sciences, University of Technology Sydney; rebecca.fox-1@uts.edu.au; Bellwood, David R.; College of Marine and Environmental Sciences, James Cook University; Australian Research Council Centre of Excellence for Coral Reef Studies; david.bellwood@jcu.edu.au. |
Around the world, the decreasing health of coral reef ecosystems has highlighted the need to better understand the processes of reef degradation. The development of more sensitive tools, which complement traditional methods of monitoring coral reefs, may reveal earlier signs of degradation and provide an opportunity for pre-emptive responses. We identify new, sensitive metrics of ecosystem processes and benthic composition that allow us to quantify subtle, yet destabilizing, changes in the ecosystem state of an inshore coral reef on the Great Barrier Reef. Following severe climatic disturbances over the period 2011-2012, the herbivorous reef fish community of the reef did not change in terms of biomass or functional groups present. However, fish-based... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Disturbances; Ecosystem state; Herbivory; Management; Monitoring; Processes; Resilience; Sediment; Thresholds. |
Ano: 2016 |
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Cembranel,Adir S.; Sampaio,Silvio C.; Remor,Marcelo B.; Gotardo,Jackeline T.; Rosa,Pábolla M. Dalla. |
ABSTRACT Geochemical background establishment is indispensable to determine the actual state of contamination of soils and sediments. However, no scientific consensus exists regarding the methodology for determining these values. In this context, this study aimed to establish the geochemical background in an Oxisol (Rhodic Hapludox) by means of an integrated method that uses direct and indirect soil analyses to identify the most appropriate calculation methodology. Soil samples were collected in a permanent preservation area of the Cascavel River watershed, PR, Brazil. The elements Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn present in soil samples were quantified by flame atomic absorption spectrometry. The use of a permanent preservation area is... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Trace elements; Heavy metals; Sediment; Soil. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000300565 |
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OLIVEIRA, M. D. de; CALHEIROS, D. F.. |
A agricultura intensiva, pastagens cultivadas, garimpo, agroindústria e os efluentes urbanos estão entre os principais fatores que causam alterações ambientais no Pantanal e rios associados (Ferreira et. al., 1994). Estas atividades estão concentradas principalmente nas áreas de planalto e têm gerado aumentos no aporte de nutrientes e sedimentos para a planície. Um bom exemplo, é rio Taquari, um dos maiores tributários da bacia do alto rio Paraguai (Brasil; 1997). A bacia hidrográfica do rio Taquari está localizada entre as latitudes de 17°00'00''S e 20°00'00''S e as longitudes de 53°00'00''W e 58°00'00''W, abrangendo uma área de aproximadamente 65.023 km2, dentro da bacia do Alto Paraguai (BAP). No fim do alto curso, o rio Taquari recebe o rio Coxim com... |
Tipo: Circular Técnica (INFOTECA-E) |
Palavras-chave: Assoreamento; Sólido suspenso; Característica; Rio Taquari; Sediment; Nutrient; Characteristic; Taquari river.; Água; Limnologia; Nutriente; Sedimento.; Limnology; Water.. |
Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/810732 |
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OLIVEIRA, M. D. de; RODRIGUES, L.. |
As macrófitas aquáticas são muito abundantes em áreas alagadas como as do Pantanal, e fornecem um vasto substrato para a microbiota, em particular para a comunidade perifítica. Foi avaliado o efeito da deposição de sedimento sobre a comunidade perifítica ao longo de 40km do trecho final do rio Taquari, em 12 estações de amostragem, em setembro de 1998. Foram coletados pecíolos de Eichhornia azurea, raspados e filtrados para análise da biomassa perifítica (clorofila a e peso seco). Foram tomadas amostras de raízes, caules e folhas da macrófita para análise do sedimento aderido. E as características da água também foram estudadas. Do sedimento suspenso analisado, 55% foi depositado até a última estação, e 86% é de origem inorgânica. A transparência da água... |
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Deposição; Macrófita aquática; Rio Taquari; Sediment; Deposition; Aquatic macrophyte; Aquatic plant; Taquari river; Wetland.; Impacto Ambiental; Perifiton; Planta Aquatica; Sedimento.; Pantanal; Environmental impact; Periphyton.. |
Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/810756 |
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Harris, Pierre; Fichez, Renaud; Fernandez, Jean Michel; Golterman, Han; Badie, Christian. |
During the past century, the sediment deposition rate has been assessed by measuring excess Pb-210 activity in a sediment core sampled in the harbour area of the Papeete Lagoon (Tahiti, French Polynesia). Dated sediment samples were analysed following a sequential extraction method to quantify five sedimentary phosphorus pools: loosely sorbed or exchangeable phosphorus, ferric iron-bound phosphorus, authigenic calcium carbonate associated phosphorus, detrital apatite and detritic inorganic phosphorus, acid organic phosphorus. Results from sediment dating showed the core to cover the period from 1865 to 1995, with a sharp change around 1957 corresponding to a doubling in sediment deposition rates. From the bottom to the top of the core, concentrations... |
Tipo: Text |
Palavras-chave: Géochronologie; Phosphore; Sédiment; Lagons coralliens; Geochronology; Phosphorus; Sediment; Coral reef lagoon. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43365/42850.pdf |
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Abrantes, F; Moita, Mt. |
Diatom and coccolithophorid abundance and diatom assemblage composition found in the water column along the Portuguese margin, during upwelling and non-upwelling conditions, are compared to the distribution patterns observed in the recent sediments from the same area. The water column results indicate a one order of magnitude increase in phytoplankton biomass during upwelling conditions (summer), with diatoms being the most important contributors. Coccolithophorids, on the contrary, dominate the phytoplankton in winter (non-upwelling), The comparison of the upwelling and non-upwelling spatial distribution of these phytoplankton groups to their sedimentary record reveals the sediment record as a reflection of the upwelling situation, preserving most of its... |
Tipo: Text |
Palavras-chave: Upwelling; Portugal; Diatomée; Colonne d'eau; Sédiment; Upwelling; Portugal; Diatom; Water column; Sediment. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43630/43253.pdf |
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Alain, Karine; Callac, Nolwenn; Ciobanu, Maria Cristina; Reynaud, Yann; Duthoit, Frederique; Jebbar, Mohamed. |
Extracting DNA from deep subsurface sediments is challenging given the complexity of sediments types, low bio-masses, resting structures (spores, cysts) frequently encountered in deep sediments, and the potential presence of enzymatic inhibitors. Promising results for cell lysis efficiency were recently obtained by use of a cryogenic mill (Lipp et al., 2008). These findings encouraged us to devise a DNA extraction protocol using this tool. Thirteen procedures involving a combination of grinding in liquid nitrogen (for various durations and beating rates) with different chemical solutions (phenol, chloroform, SDS, sarkosyl, proteinase, GTC), or with use of DNA recovery kits (MagExtractor (R)) were compared. Effective DNA extraction was evaluated in terms of... |
Tipo: Text |
Palavras-chave: Sediment; DNA extraction; Deep subsurface biosphere. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16691/14364.pdf |
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Frere, L.; Paul-pont, I.; Rinnert, Emmanuel; Petton, Sebastien; Jaffre, J; Bihannic, Isabelle; Soudant, P.; Lambert, C.; Huvet, Arnaud. |
The concentration and spatial distribution of microplastics in the Bay of Brest (Brittany, France) was investigated in two surveys. Surface water and sediment were sampled at nine locations in areas characterized by contrasting anthropic pressures, riverine influences or water mixing. Microplastics were categorized by their polymer type and size class. Microplastic contamination in surface water and sediment was dominated by polyethylene fragments (PE, 53–67%) followed by polypropylene (PP, 16–30%) and polystyrene (PS, 16–17%) microparticles. The presence of buoyant microplastics (PE, PP and PS) in sediment suggests the existence of physical and/or biological processes leading to vertical transfer of lightweight microplastics in the bay. In sediment (upper... |
Tipo: Text |
Palavras-chave: Microplastic; Coastal ecosystem; Surface water; Sediment; Raman spectroscopy; Hydrodynamic; Dispersal particle modelling. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00379/48994/51083.pdf |
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De Wit, Rutger; Troussellier, Marc; Courties, Claude; Buffan-dubau, Evelyne; Lemaire, Emmanuelle. |
We experimentally simulated the temporality of the interactions between intertidal seagrasses and phytoplankton in the context of nutrient enrichment from continental origin. Phytoplankton development was retarded after 1-day exposure to intertidal Zostera noltii Hornemann vegetation samples, with respect to control treatments. This was not explained by resource competition and we hypothesized a direct interference between seagrass leaves and phytoplankton. After separation from the vegetation in 5-day incubations, the final yield of large phytoplankton, mainly diatoms and haptophytes, was determined by nutrient loading. In contrast, Synechococcus-like cells (SYN), phototrophic picoeukaryotes and nanophytoplankton decreased after day 3, most likely due to... |
Tipo: Text |
Palavras-chave: Competition; Allelopathy; Zostera noltii; Sediment; Intertidal vegetation; Flow cytometry; Photosynthetic pigments. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00106/21717/19414.pdf |
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Yang, Hailin; Lu, Hailong; Ruffine, Livio. |
Two ~1000 cm long sediment cores were recovered from the Sea of Marmara, one with the occurrence of gas hydrates in the Western High, and the other without hydrates in the Cinarcik Basin. Differences in mineralogical and chemical compositions have been identified between the two sediment cores. Based on the results of the mineralogical and geochemical analyses, the main sources of the sediments are quite similar for both investigated areas, but the authigenic components are different, particularly iron sulfides and carbonates. Authigenic Fe(II) carbonate are much higher in Core MRS-CS-05 in the Western High, while crystalline Fe(III) phases are more abundant in Core MRS-CS-16 in the Cinarcik Basin. Notably, the enrichments of greigite (Fe3S4), a metastable... |
Tipo: Text |
Palavras-chave: Iron geochemistry; The Sea of Marmara; Sediment; Redox environment. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00423/53455/54347.pdf |
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Sultan, Nabil; Gaudin, Mathieu; Berne, Serge; Canals, Miquel; Urgeles, Roger; Lafuerza, Sara. |
To improve understanding of evolution of submarine canyons, a three-dimensional slope-stability model is applied to Bourcart Canyon in the western Gulf of Lions in the Mediterranean Sea. The model builds on previous work by Chen and others, and it uses the upper bound theorem of plasticity to calculate the factor of safety of a kinematically admissible failing mass. Examples of three-dimensional failure surfaces documented in the literature were used to test the model formulation. Model application to Bourcart Canyon employed the results of a detailed stratigraphic analyses based on data acquired by swath bathymetry, sub-bottom profiling, high-resolution seismic reflection surveys, and piston coring. The sediment layers were also characterized using... |
Tipo: Text |
Palavras-chave: Cascadia accretionary complex; Upper bound theorem; Stability analysis; Continental slope; Limit equilibrium; Western gulf; Offshore; Margin; Initiation; Sediment. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2410.pdf |
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Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor... |
Tipo: Text |
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.pdf |
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Cantet, Franck; Hervio-heath, Dominique; Caro, A; Le Mennec, Cecile; Monteil, Caroline; Quemere, Catherine; Jolivet-gougeon, Anne; Colwell, Rita R.; Monfort, Patrick. |
Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae are human pathogens. Little is known about these Vibrio spp. in the coastal lagoons of France. The purpose of this study was to investigate their incidence in water, shellfish and sediment of three French Mediterranean coastal lagoons using the most probable number-polymerase chain reaction (MPN-PCR). In summer, the total number of V. parahaemolyticus in water, sediment, mussels and clams collected from the three lagoons varied from 1 to >1.1 x 10.3 MPN/l, 0.09 to 1.1 x 10.3 MPN/ml, 9 to 210 MPN/g and 1.5 to 2.1 MPN/g, respectively. In winter, all samples except mussels contained V. parahaemolyticus, but at very low concentrations. Pathogenic (tdh- or trh2-positive) V. parahaemolyticus were... |
Tipo: Text |
Palavras-chave: Vibrio; Lagoons; Shellfish; Water; Sediment; Human pathogen. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00148/25890/23889.pdf |
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Registros recuperados: 165 | |
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