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| Registros recuperados: 91 | |
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| Berg, Gm; Balode, M; Purina, I; Bekere, S; Bechemin, Christian; Maestrini, Serge. |
| Trends in nitrogen utilization, determined with N-15-labeled substrates, were related to blooms of distinct phytoplankton groups in the Gulf of Riga, Baltic Sea, during May, June and July 1999. The dominant phytoplankton groups included diatoms, cryptophytes, dinoflagellates, and filamentous cyanobacteria. As the water column became progressively more stratified over the growing season, diatoms comprised a smaller proportion of the total phytoplankton assemblage and almost disappeared by late summer. Their disappearance correlated with undetectable surface-water nitrate concentrations and low nitrate uptake rates (5 to 8% of total nitrogen uptake). Diatoms were the only phytoplankton group significantly associated with the uptake of oxidized nitrogen... |
| Tipo: Text |
Palavras-chave: Nitrogen uptake; DON; Nitrate; Diatoms; Cyanobacteria; Cryptophytes; Baltic Sea; Gulf of Riga. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10207/7595.pdf |
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| Saher, Margot H.; Gehrels, W. Roland; Barlow, Natasha L. M.; Long, Antony J.; Haigh, Ivan D.; Blaauw, Maarten. |
| We present a new, diatom-based sea-level reconstruction for Iceland spanning the last similar to 500 years, and investigate the possible mechanisms driving the sea-level changes. A sea-level reconstruction from near the Icelandic low pressure system is important as it can improve understanding of ocean atmosphere forcing on North Atlantic sea-level variability over multi-decadal to centennial timescales. Our reconstruction is from Vioarholmi salt marsh in Snafellsnes in western Iceland, a site from where we previously obtained a 2000-yr record based upon less precise sea-level indicators (salt-marsh foraminifera). The 20th century part of our record is corroborated by tide-gauge data from Reykjavik. Overall, the new reconstruction shows ca 0.6 m rise of... |
| Tipo: Text |
Palavras-chave: Diatoms; Ocean dynamics; Iceland; Little Ice Age; Sea-level rise; NAO. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00352/46283/45963.pdf |
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| Sun, Meiqin; Lan, Dongzhao; Cao, Zhimin. |
| A quantitative study was undertaken on diatoms from cores (SA08-34) obtained from the southwestern continental slope of the South China Sea (SCS). A total of 165 diatom species belonging to 45 genera were identified. We constructed a stratigraphic subdivision and correlation according to the characteristics of diatom assemblages together with 14 C dating and carbonate analysis. We also discuss the sedimentary environment in the sea area since the last glacial times. The research shows that the diatom assemblages coincide with interglacial and glacial times, and changes in diatom abundance reflect the instability of the climate in the southern part of the SCS, such that short-term, temperature descending events correlate with the interglacial interval. The... |
| Tipo: Text |
Palavras-chave: Diatoms; Last glacial times; Sedimentary environment; South China Sea. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00497/60853/65095.pdf |
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| Kalansky, Julie F.; Robinson, Rebecca S.; Popp, Brian N.. |
| The nitrogen isotopic composition of organic matter contained within diatom frustules of different sediment size fractions from the Guaymas Basin, Gulf of California, suggests that multiple nutrient cycling processes can be examined from a single sediment sample. The diatom-bound delta(15)N values from the greater and less than 63 mu m size fractions were analyzed from six intervals of core MD02-2517, each representing similar to 30-40 years. The diatom-bound delta(15)N values are compared to bulk sedimentary delta(15)N values, weight percent biogenic opal, and weight percent organic carbon. Bulk sedimentary delta(15)N values range from 10 parts per thousand to 12.5 parts per thousand and diatom-bound delta(15)N values of the <63 mu m size fraction from... |
| Tipo: Text |
Palavras-chave: Gulf of California; Diatoms; Export flux; Nitrogen cycling; Nitrogen isotopes. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00227/33836/32444.pdf |
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| Nantke, Carla K. M.; Frings, Patrick J.; Stadmark, Johanna; Czymzik, Markus; Conley, Daniel J.. |
| Si fluxes from the continents to the ocean are a key element of the global Si cycle. Due to the ability of coastal ecosystems to process and retain Si, the ‘coastal filter’ has the potential to alter Si fluxes at a global scale. Coastal zones are diverse systems, sensitive to local environmental changes, where Si cycling is currently poorly understood. Here, we present the first palaeoenvironmental study of estuarine biogenic silica (BSi) fluxes and silicon isotope ratios in diatoms (δ30Sidiatom) using hand-picked diatom frustules in two sediment cores (CBdist and CBprox) from the Chesapeake Bay covering the last 12000 and 8000 years, respectively. Constrained by the well-understood Holocene evolution of the Chesapeake Bay, we interpret variations in Si... |
| Tipo: Text |
Palavras-chave: Diatoms; Estuarine sediments; Human impact; Si isotopes. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00589/70083/68065.pdf |
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| González-fernández, Carmen; Toullec, Jordan; Lambert, Christophe; Le Goïc, Nelly; Seoane, Marta; Moriceau, Brivaela; Huvet, Arnaud; Berchel, Mathieu; Vincent, Dorothée; Courcot, Lucie; Soudant, Philippe; Paul-pont, Ika. |
| The potential presence of nanoplastics (NP) in aquatic environments represents a growing concern regarding their possible effects on aquatic organisms. The objective of this study was to assess the impact of polystyrene (PS) amino-modified particles (50 nm PSNH2) on the cellular and metabolic responses of the diatom Chaetoceros neogracile cultures at two essential phases of the growth cycle, i.e. exponential (division) and stationary (storage) phases. Both cultures were exposed for 4 days to low (0.05 μg mL−1) and high (5 μg mL−1) concentrations of PS-NH2. Exposure to NP impaired more drastically the major cellular and physiological parameters during exponential phase than during the stationary phase. Only an increase in ROS production was observed at... |
| Tipo: Text |
Palavras-chave: Nanoplastics; Diatoms; Physiology; Transparent exopolymer particles. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00491/60235/63627.pdf |
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| Sterrenburg, F.A.S.; Wolf, H. de. |
| Johannes Kinker (1823-1900) was a typical representative of the Victorian ‘amateur-savant’. As a wellto- do stockbroker he was able to invest considerable time and money into studies of nature, first entomology and subsequently diatoms. The latter subject flourished in the late 19th century and, among his international contemporaries, Kinker was regarded as “the only Dutch diatomist of renown”. There is a marked discrepancy between this reputation in his own time and his complete obscurity since, for which there are two reasons; Kinker did not publish, and his collection was not known to exist. Our discovery of the virtually intact Kinker diatom collection after it had vanished for a century can be regarded as a cultural heritage conservation paradigm; the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Diatoms; Typification; 42.35. |
| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/215472 |
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| Romdhane, M.S.; Ben Rejeb-Jenhani, A.. |
| La détérioration de la qualité des eaux de la lagune de Boughrara, conséquence de divers apports polluants et d’échanges d’eaux limités avec la mer, s’est traduite par un accroissement sévère de l’eutrophisation du milieu se manifestant notamment par d’importantes proliférations microalgales. L’analyse de l’évolution de l’ensemble des groupes phytoplanctoniques a montré que les périodes de forte biomasse algale sont caractérisées par des développements monospécifiques. L’importance relative croissante de la classe des dinoflagellés se manifestent par un net accroissement du rapport dinoflagellés / diatomées. Le très fort développement de l’espèce Gymnodinium cf nagasakiense , (densités maximales de l’ordre de 6.10 6 cellules par litre ) espèce connue... |
| Tipo: Journal Contribution |
Palavras-chave: Diatoms; Environmental factors; Lagoons; Phytoplankton; Geographical distribution. |
| Ano: 2002 |
URL: http://hdl.handle.net/1834/236 |
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| Loza, S.; Sánchez, M.; Carmenate, M.; Siqueiros-Beltrones, D.. |
| Se presenta la información sobre la especie de diatomea Campylostylus normannianus (Greville, 1862) Gerloff, Natour & Rivera, 1978 encontrada en la bahía de Jigüey y que no había sido identificada en los estudios taxonómicos de las microalgas de Cuba, por lo que se pudiera considerar una contribución a la diversidad de las microalgas marinas del país. Este es un taxon que crece en ambientes hipersalinos. Sin embargo, en este ecosistema se presenta acompañada de otros taxa de diatomeas, las que son abundantes y características de ecosistemas de manglar. |
| Tipo: Journal Contribution |
Palavras-chave: Diatoms; Diatoms; Http://aims.fao.org/aos/agrovoc/c_32657. |
| Ano: 2011 |
URL: http://hdl.handle.net/1834/4058 |
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| Moreira González, A.. |
| Algunas especies de diatomeas del género Pseudo-nitzschia producen toxinas que causan envenenamiento amnésico por mariscos. En abril de 2009, se observó un florecimiento de diatomeas en un área semicerrada de la bahía de Cienfuegos, Cuba, en el que se identificó a la especie potencialmente tóxica Pseudo-nitzschia cf. multistriata, sin embargo no se observaron efectos nocivos para la fauna marina ni fueron reportados síndromes de toxicidad en humanos. El presente trabajo describe la composición y la concentración del fitoplancton en el área del florecimiento con enfásis en la especie Pseudo-nitzschia cf. multistriata. |
| Tipo: Journal Contribution |
Palavras-chave: Abundance; Bays; Diatoms; Phytoplankton. |
| Ano: 2013 |
URL: http://hdl.handle.net/1834/4920 |
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| Tapia, M.E.; Torres Ch., G.. |
| El principal objetivo fue de conocer la disponibilidad de la reserva alimenticia (fitoplancton), como un factor que puede influenciar la distribución y abundancia del krill antártico, registrados durante la VII Expedición Ecuatoriana a la Antártida en enero/1998 en el B/I ORION (INOCAR). La biomasa fitoplanctónica en el Estrecho Bransfield, registró altas concentraciones hacia el sur oeste del estrecho dominado principalmente por Cryptomonas spp. entre 1000.000 a 2200.000 cel/l, las menores concentraciones se registraron hacia las Islas Shetland del Sur entre 575.000 a 693.000 cel/l. compuestas principalmente por las diatomeas, Nitzschia delicatissima, N. longissima, Thalassiosira spp., y el Dinoflagelado gymnodinium spp., los cuales se presentaron... |
| Tipo: Journal Contribution |
Palavras-chave: Distribution; Availability; Abundance; Diatoms; Phytoplankton; El Nino phenomena; Distribution; Phytoplankton; Diatoms. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/3852 |
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| Huangh, Yuanhui; Lan, Dongzhao. |
| Core D（21°23′02″N，116°47′13″E, water depth 405 m）was sampled from the upper slope from the northeastern South China Sea (SCS) and applied to analyze the sedimentary environmental change in this sea area since the last glacial stage. The results of grain size analysis, diatom analysis and detrital mineral analysis were well matched. We divided the core D into two layers. The surface sand layer (0 - 2 cm) consisted of residual sediments, which might be originally the sediment in the late Pleistocene and later suffered from being transformed in the post glacial transgression. The lower layer (2 - 130 cm) was quite different from the surface one, which might mainly result from a neritic sedimentary environment in the last glacial stage. Two sedimentary cycles... |
| Tipo: Journal Contribution |
Palavras-chave: Grain size; Diatoms; Sedimentary environments. |
| Ano: 2007 |
URL: http://hdl.handle.net/1834/5836 |
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| Torres, G.; Andrade, C.. |
| Se realizó un monitoreo del plancton en el estuario de San Lorenzo en junio 2006. En los resultados se registró 128 especies del fitoplancton (método cuantitativo) y 50 especies (cualitativo). Las diatomeas más representativas fueron S. costatum, T. nitzschioides, P. longissima, L. danicus, Navicula sp., P. sulcata: T. nitzschioides. Thalassiosira sp. y flagelados (cuantitativo); S. costatum, Coscinodiscus sp., N. sigma y P. Sulcata (cualitativo). La presencia de Gymnodinium sp. P. maximun y M. rubrum podría asociarse con la formación de mareas rojas al interior del estuario. En los resultados del zooplancton registrarón 16 taxas constituidos mayoritariamente por Zoeas de Brachiura y Copépodos, distribudidos en toda el área de estudio principalmente en... |
| Tipo: Journal Contribution |
Palavras-chave: Plankton; Diatoms; Phytoplankton; Zooplankton; Biomass; Fish larvae; Eggs; Abundance; Estuaries; Species diversity; Zooplankton; Biomass; Eggs; Estuaries; Plankton; Phytoplankton; Fish larvae; Species diversity; Diatoms; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_2502; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_5950; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_2924; Http://aims.fao.org/aos/agrovoc/c_33954; Http://aims.fao.org/aos/agrovoc/c_32657. |
| Ano: 2007 |
URL: http://hdl.handle.net/1834/2378 |
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| Registros recuperados: 91 | |
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