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| Registros recuperados: 47 | |
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| Rodríguez, A.J.; Arpajón, I.; Castaño, Z.; Marsán, R.; Lugo, D.; Roevros, N.; Chou, L.; Rojas, N.; Heydrich, M.. |
| The Almendares River constitutes the most important superficial stream in Cuban capital, that finishes in the Metropolitan Park of Havana, which is an entertaining centre. The objective of this work is to determine the presence of toxic inorganic pollutants in the Almendares River water. 10 samplings were carried out from June 2003 to May 2004 in 14 stations established along the last 10 km of the river and 3 tributaries. The quantification of nitrates, nitrites and ammonium was done by spectrophotometric methods The concentration of heavy metals in the dissolved and particulate phase was determined by atomic emission spectrometry. The total microbial charge was determined by epifluorescency. Were found high levels of ammonium and nitrites, as well as high... |
| Tipo: Proceedings Paper |
Palavras-chave: Rivers; Freshwater pollution; Heavy metals; Rivers; Heavy metals; Http://aims.fao.org/aos/agrovoc/c_6617; Http://aims.fao.org/aos/agrovoc/c_2223. |
| Ano: 2006 |
URL: http://hdl.handle.net/1834/2086 |
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| Luzuriaga de Cruz, M.. |
| El presente trabajo corresponde al análisis de zooplancton colectado en cinco estaciones localizadas en el río Guayas. La primera estación estuvo situada 10 km. río arriba de la confluencia del río Babahoyo con el río Daule, en un pozo acuífero. Las otras estaciones se situaron en cuatro sitios consecutivos a lo largo del río Guayas. En este trabajo se han identificado 10 especies: Brachionus plicatilis (O. F. Muller) (Rotifera), Alona cambouei Guerne and Richard, 1893; Moina micrura Kurz, 1874 (Cladocera); Acartia tonsa Dana, 1848; Oithona dissimilis Linberg, 1940; Oithona neotropica Herbs, 1967; Oithona oligohalina Fonseca o Bjornberg, 1976; Mesocyclops longisetus (Thiebaud, 1914) y Pseudodiaptomus longispinosus Chad, 1989 (Copepoda). Las especies... |
| Tipo: Journal Contribution |
Palavras-chave: Zooplankton; Fresh water; Geographical distribution; Rivers; Estuaries; Brackish water; Zooplankton; Geographical distribution; Rivers; Estuaries; Brackish water; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_6617; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_1049. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/2295 |
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| Revelo, W.. |
| Durante el 2009 (excepto mayo, agosto y septiembre), se analizaron un total de 3 772 especímenes de peces conformados por 16 especies, predominando la dica con 1561 individuos (42,3%), las menos capturadas fueron róbalo y chame con un individuo cada una (0,03%). La proporción de sexo macho hembra, talla promedio de captura y media de madurez sexual de las principales especies de peces fue: dama (1: 1,16; 23,7 y 20 cm LT), dica (1: 1,15; 17,3 y 16 cm LT), guanchiche (1: 1,2; 29 y 20 cm LT), ratón (1: 1,25; 23,5 y 19 cm LT) y bocachico (1:1,06; 21,6 y 20 cm LT). En los estadios de madurez sexual, la mayoría de las especies se encontraron en estadio I y II correspondientes a individuos hembras inmaduras; sin embargo, para el guanchiche predominaron las... |
| Tipo: Journal Contribution |
Palavras-chave: Rivers; Species diversity; Sexual maturity; Growth rate; Catch composition; Freshwater fish. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/4790 |
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| Mauad,Melina; Miserendino,M. Laura; Risso,Miguel A.; Massaferro,Julieta. |
| ABSTRACT Seven sites were examined in the Challhuaco-Ñireco system, located in the reserve of the Nahuel Huapi National Park, however part of the catchment is urbanized, being San Carlos de Bariloche (150,000 inhabitants) placed in the lower part of the basin. Physico-chemical variables were measured and benthic macroinvertebrates were collected during three consecutive years at seven sites from the headwater to the river outlet. Sites near the source of the river were characterised by Plecoptera, Ephemeroptera, Trichoptera and Diptera, whereas sites close to the river mouth were dominated by Diptera, Oligochaeta and Mollusca. Regarding functional feeding groups, collector-gatherers were dominant at all sites and this pattern was consistent among years.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Patagonian; Rivers; Macroinvertebrates; Biotic indexes; Water quality. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212015000300348 |
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| Martias, Chloe; Tedetti, Marc; Lantoine, Francois; Jamet, Leocadie; Dupouy, Cecile. |
| The eastern lagoon of New Caledonia (NC, Southwest Pacific), listed as a UNESCO World Heritage site, hosts the world's second longest double-barrier coral reef. This lagoon receives river inputs, oceanic water arrivals, and erosion pressure from ultramafic rocks, enriched in nickel (Ni) and cobalt (Co). The aim of this study was to characterize colored dissolved organic matter (CDOM), as well as to determine its main sources and its possible relationships (through the use of Pearson correlation coefficients, r) with biogeochemical parameters, plankton communities and trace metals in the NC eastern lagoon. Water samples were collected in March 2016 along a series of river/lagoon/open-ocean transects. The absorption coefficient at 350 nm (a(350)) revealed... |
| Tipo: Text |
Palavras-chave: CDOM; Fluorescence; Trace metals; Southwest Pacific; Coral reef lagoon; Rivers. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00481/59307/62061.pdf |
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| Prado, M.; Bucheli, R.; Calderón.G.. |
| La composición, distribución y abundancia de las comunidades planctónicas de los ríos Mocache, Vinces, Babahoyo y el Humedal Abras de Mantequilla (Provincia de Los Ríos) fue analizada durante el 2009. Mensualmente en 29 zonas de pesca se recolectaron muestras para el análisis cualitativo y cuantitativo de fitoplancton, zooplancton e ictioplancton. Se identificaron 139 grupos fitoplanctónicos, 63 de zooplancton y fauna acompañante, así como 16 géneros y ocho especies de larvas de peces. La densidad de fitoplancton osciló entre 27 y 1 476 cel.m-3, mientras que el zooplancton entre 3 y 335 org.m-3 y las larvas de peces entre 2 y 1 026 org.m-3. Las especies dominantes fueron las diatomeas Fragilaria cf. longissima y Polymyxus coronalis, el insecto Baetis sp. y... |
| Tipo: Journal Contribution |
Palavras-chave: Rivers; Plankton studies; Composition; Distribution. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/4789 |
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| The increasing number of deteriorating old dams that need renovation or have lost their function make dam removal a viable management option. There are at least four major reasons for dam removal: safety, law and policy, economy, and ecology. Here we discuss 17 Swedish dams that were recently considered for removal. Because dam removal usually causes controversy, dam removal initiatives may succeed, fail, or result in a compromise such as a bypass channel for migrating fish. We identify and discuss three major obstructions to dam removal: funding, cultural-historical values, and threatened species. To facilitate dam removal, the reasons for, and the effects of, dam removal must be carefully explained, and the public and stakeholders must be kept... |
| Tipo: Peer-Reviewed Insight |
Palavras-chave: Controversies; Dam removal; Information; Obstructions; Reservoirs; Rivers; Stakeholder involvement; Sweden. |
| Ano: 2009 |
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| Delgado, G.; Méndez, L.; Lechuga, C. H.. |
| Durante un año fueron estudiados los dinoflagelados bentónicos nocivos agrupados sobre el sedimento de una ensenada donde desemboca el río Jaimanitas (región NW de Ciudad de la Habana). Se muestrearon seis puntos fijos sobre tres tipos de sedimentos: fango arenoso, areno-fangoso y arenoso. Prorocentrum fue el género dominante con cuatro especies y dentro de estas Prorocentrum lima, fue la más abundante en distribución espacial y temporal. La variación espacial de la densidad celular osciló entre 0.74 X 103 cél/cm3 y 2.36 X 103 cél/cm3 y la temporal fluctuó entre 0.12 x 103 cél/cm3 y 2.09 x 103 cél/cm3, registrándose el mínimo en enero y febrero, mientras que el máximo se obtuvo en agosto. Por el método del Escalado Multidimensional (MDS), se pudieron... |
| Tipo: Preprint |
Palavras-chave: Sediments; Rivers; Rivers; Http://aims.fao.org/aos/agrovoc/c_6617. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/3839 |
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| RIBAS,CAMILA C.; ALEIXO,ALEXANDRE. |
| Abstract: Amazonia has been a focus of interest since the early days of biogeography as an intrinsically complex and extremely diverse region. This region comprises an intricate mosaic that includes diverse types of forest formations, flooded environments and open vegetation. Increased knowledge about the distribution of species in Amazonia has led to the recognition of complex biogeographic patterns. The confrontation of these biogeographic patterns with information on the geological and climatic history of the region has generated several hypotheses dedicated to explain the origin of the biological diversity. Genomic information, coupled with knowledge of Earth’s history, especially the evolution of the Amazonian landscape, presents fascinating... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazonia; Biogeography; Birds; Conservation; Diversification; Rivers. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000600611 |
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| Fiori, Leandro Fabrício; Sacramento, Patricia Almeida; Corbetta, Daiany de Fátima; Pereira, Lucas Milani; Benedito, Evanilde. |
| The particulate organic carbon (POC) is an important energy source present in the food chain of detritivorous fish. Considering its importance, this study aimed to investigate the effect of the flood pulse on the composition of the POC in a neotropical floodplain. For this, we analyzed the seasonal variations of the carbon isotopic composition (δ13C) and nitrogen (δ15N) in two different hydrological periods in the years 2000 and 2009. Sampling of potential sources of primary producers, as well as the POC, was held in different subsystems of the floodplain of the upper Paraná river (subsystems of the rivers Parana, Baía and Ivinheima). In 2000, there were significant differences on isotopic signature (δ13C) of the POC, unlike what was seen in 2009, where... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 2.05.02.00-1 potamophase; Limnophase; Rivers; Water level; Wetlands Ecologia de Ecossistemas. |
| Ano: 2014 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/20336 |
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| Perbiche-Neves,Gilmar; Rocha,Carlos E.F. da; Nogueira,Marcos G.. |
| Species richness and geographical distribution of Cyclopoida freshwater copepods were analyzed along the "La Plata" River basin. Ninety-six samples were taken from 24 sampling sites, twelve sites for zooplankton in open waters and twelve sites for zooplankton within macrophyte stands, including reservoirs and lotic stretches. There were, on average, three species per sample in the plankton compared to five per sample in macrophytes. Six species were exclusive to the plankton, 10 to macrophyte stands, and 17 were common to both. Only one species was found in similar proportions in plankton and macrophytes, while five species were widely found in plankton, and thirteen in macrophytes. The distinction between species from open water zooplankton and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: La Plata River basin; Reservoirs; Rivers; Zooplankton. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702014000300005 |
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| Registros recuperados: 47 | |
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