Consulta: subjectFacets:"Diatoms"
Registros recuperados: 91
Data/hora: 01/06/2024 14:16:25

Inhibition of attachment of some fouling diatoms and settlement of Ulva lactuca zoospores by film-forming bacterium and their extracellular products isolated from biofouled substrata in Northern Chile
Provedor de dados: 69
Autores: Silva-Aciares,Fernando; Riquelme,Carlos.
The biofouling of surfaces submerged in the marine environment includes primary colonization of the substrate by microorganisms including bacteria, microalgae, and microscopic reproductive propagules of macroorganisms such as algal zoospores. The present study reports the evaluation of the inhibitory potential of biofilms and extracellular products (EP) of the indigenous bacterium Alteromonas sp strain Ni1-LEM on the settlement of marine biofouling such as: (i) eight marine benthic diatoms and (ii) zoospores of the alga Ulva lactuca, as well as the germination of these zoospores and was compared with reference strains with proven antifouling properties, Halomonas marina (ATCC 25374) and Pseudoalteromonas tunicata. Highest antifouling activity was found for...
Tipo: Journal article
Palavras-chave: Alteromonas sp; Antifouling bacteria; Antifouling compounds; Diatoms; Marine microfouling; Ulva zoospores.
Ano: 2008
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000100006

MORPHOLOGY OF THE SYMMETRICAL MORPHOTYPES OF CENTRONELLA REICHELTII VOIGT (FRAGILARIACEAE, BACILLARIOPHYCEAE) FROM PATAGONIAN ENVIRONMENTS
Provedor de dados: 73
Autores: Echenique,Ricardo O.; Guerrero,José M.
The ultrastructure of symmetrical valves of Centronella reicheltii Voigt, resembling the former C. rostafinskii Woloszynska, is studied for the first time, and their morphology is compared with the asymmetrical forms. Valve morphology and morphometry of both morphotypes are similar and only differ in the shape and striation pattern of the valve centre and the arrangement of the arm bases. However, since they occur in environments with different trophic status, the new combination C. reicheltii f. rostafinskii is proposed for the symmetrical valves, because this distinction may provide ecologically useful information.
Tipo: Journal article
Palavras-chave: Trophic status; Diatoms; Taxonomy; Morphological variability; Ultrastructure.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432004000100003

Новые и редкие для Черного моря виды диатомовых и динофитовых водорослей.
Provedor de dados: 13
Autores: Сеничева, М. И.
В результате многолетних круглогодичных наблюдений (1968 - 1969, 1983 – апрель 2002  гг.) за развитием фитопланктона в прибрежной зоне юго-западного Крыма выявлены новые для флоры Черного моря виды диатомовых водорослей - Asterionellopsis glacialis (Castracane) F.E. Round, Chaetoceros tortissimus Gran, Thallassiosira nordenskioeldii Cleve, Lioloma pacificum (Cupp) Hasle, Pseudonitzschia inflatula (Hasle), динофитовых - Dinophysis odiosa (Pavillard) Tai &amp; Scogsberg, а также редкий у побережья  Крыма Gymnodinium sanguineum Hirasaka. Описана новая разновидность диатомовой водоросли Chaetoceros diversus Cleve - Ch. diversus var. papilionis Senicheva.
Tipo: Journal Contribution
Palavras-chave: Diatoms; Diatoms; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2002
URL: http://repository.ibss.org.ua/dspace/handle/99011/518

Оценка объемов и площадей поверхности диатомовых водорослей при помощи трехмерных моделей
Provedor de dados: 13
Autores: Лях, А. М.; Токарев, Ю. Н.
Рассмотрен новый метод точной оценки объемов и площадей поверхности диатомовых водорослей. Используются два типа трехмерных моделей - цилиндрические и каркасные, которые наиболее точно имитируют форму микроводорослей с прямыми и изогнутыми вдоль вертикальной оси панцирями. Объемы и площади моделей рассчитываются автоматически по простым формулам, при помощи разработанной компьютерной программы. Программа позволяет строить трехмерные модели диатомовых на основе очертаний их створок и форм вертикальных осей панцирей. С помощью программы построено несколько тысяч трехмерных моделей микроводорослей рода Gomphonema Ehr., и проанализированы различия между параметрами трехмерных моделей и подобных геометрических фигур. Предлагается считать трехмерные модели...
Tipo: Journal Contribution
Palavras-chave: Диатомовые микроводоросли; Объем и площадь поверхности клетки; Трехмерная модель клетки; Цилиндрическая и каркасная модели; Diatoms; Biovolume and surface area; Three-dimensional cell model; Cylindrical and loft models Diatoms Diatoms http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2005
URL: http://repository.ibss.org.ua/dspace/handle/99011/232

Геометрическое  моделирование диатомовых  водорослей  рода Cymbella Agardh
Provedor de dados: 13
Autores: Лях, А. М.
Приведем алгоритм построения трёхмерных геометрических моделей диатомовых рода Cymbella. Описаны качественные признаки, по которым выделены типовые формы створок. На основе типовых форм построены ЗD-модели клеток, которые сопоставлялись с геометрической фигурой «цимбеллоид». Выявлено, что последний существенно занижает объемы клеток. Предложены модели для экспресс-оценки биомассы водорослей с погрешностью, не превышающей 10%.
Tipo: Journal Contribution
Palavras-chave: Models; Diatoms; Models; Diatoms; Http://aims.fao.org/aos/agrovoc/c_4881; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2007
URL: http://repository.ibss.org.ua/dspace/handle/99011/611

Диатомовые водоросли планктона Черного моря
Provedor de dados: 13
Autores: Прошкина-Лавренко, А. И.
Tipo: Book
Palavras-chave: Диатомовые водоросли; Фитопланктон; Морфология; Систематика; Diatoms; Phytoplankton; Morphology Diatoms Diatoms http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 1955
URL: http://repository.ibss.org.ua/dspace/handle/99011/569

Capacity of the potentially toxic diatoms Pseudo-nitzschia mannii and Pseudo-nitzschia hasleana to tolerate polycyclic aromatic hydrocarbons
Provedor de dados: 5
Autores: Ben Garali, Sondes Melliti; Sahraoui, Ines; Ben Othman, Hiba; Kouki, Abdessalem; De La Iglesia, Pablo; Diogene, Jorge; Lafabrie, Celine; Andree, Karl B.; Fernandez-tejedor, Margarita; Mejri, Kaouther; Meddeb, Marouan; Pringault, Olivier; Hlaili, Asma Sakka.
This study investigates the effects of polycyclic aromatic hydrocarbons (PAHs) on two potentially toxic Pseudonitzschia hasleana and P. mannii, isolated from a PAH contaminated marine environment. Both species, maintained in non-axenic cultures, have been exposed during 144 h to increasing concentrations of a 15 PAHs mixture. Analysis of the domoic acid, showed very low concentrations. Dose?response curves for growth and photosynthesis inhibition were determined. Both species have maintained their growth until the end of incubation even at the highest concentration tested (120 ?g l-1), Nevertheless, P mannii showed faster growth and seemed to be more tolerant than P. hasleana. To reduce PAH toxicity, both species have enhanced their biovolume, with a...
Tipo: Text
Palavras-chave: Diatoms; Pseudo-nitzschia; PAHs mixtures; Biodegradation; Eco-toxicology.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00690/80215/83300.pdf

Observations on the relationship between the Antarctic coastal diatoms Thalassiosira antarctica Comber and Porosira glacialis (Grunow) Jorgensen and sea ice concentrations during the late Quaternary
Provedor de dados: 5
Autores: Pike, Jennifer; Crosta, Xavier; Maddison, Eleanor J.; Stickley, Catherine E.; Denis, Delphine; Barbara, Loic; Renssen, Hans.
The available ecological and palaeoecological information for two sea ice-related marine diatoms (Bacillariophyceae), Thalassiosira antarctica Comber and Porosira glacialis (Grunow) Jorgensen, suggests that these two species have similar sea surface temperature (SST), sea surface salinity (SSS) and sea ice proximity preferences. From phytoplankton observations, both are described as summer or autumn bloom species, commonly found in low SST waters associated with sea ice, although rarely within the ice. Both species form resting spores (RS) as irradiance decreases, SST falls and SSS increases in response to freezing ice in autumn. Recent work analysing late Quaternary seasonally laminated diatom ooze from coastal Antarctic sites has revealed that...
Tipo: Text
Palavras-chave: East Antarctica; Quaternary; Diatoms; Sea ice.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/00220/33092/82663.pdf

Succession of primary producers and micrograzers in a coastal ecosystem dominated by Phaeocystis globosa blooms
Provedor de dados: 5
Autores: Grattepanche, Jean-david; Breton, Elsa; Brylinski, Jean-michel; Lecuyer, Eric; Christaki, Urania.
The community structures and succession of phytoplankton, protozooplankton and copepods were studied from February 2007 to July 2009 in a coastal area of the eastern English Channel subject to Phaeocystis globosa blooms. While diatom blooms preceded P. globosa blooms each year, the community structure and stock of heterotrophic protists appeared to be related to the dominant P. globosa life cycle stages. In 2007, the dominance of large colonies (&gt; 100 mu m, up to 316 mu g C L(-1)), which resulted in a high biomass of healthy free cells (up to 132 mu g C L(-1)), accompanied high spirotrich ciliate stocks (up to 58 mu g C L(-1)) and high abundances of the copepods Acartia clausi and Temora longicornis (up to 11 ind. L(-1)). In 2008, the bloom which lasted...
Tipo: Text
Palavras-chave: Phaeocystis globosa; Diatoms; Micrograzer community; Eastern English Channel.
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00373/48468/48714.pdf

Effects of phytoplankton community composition and productivity on sea surface pCO(2) variations in the Southern Ocean
Provedor de dados: 5
Autores: Takao, Shintaro; Nakaoka, Shin-ichiro; Hashihama, Fuminori; Shimada, Keishi; Yoshikawa-inoue, Hisayuki; Hirawake, Toru; Kanda, Jota; Hashida, Gen; Suzuki, Koji.
The Southern Ocean is a vast net sink for atmospheric carbon dioxide (CO2), with marine phytoplankton playing a crucial role in CO2 fixation. We assessed how changes in the dominant phytoplankton community and net primary productivity (NPP) affected variations in the partial pressure of CO2 in surface water (pCO(2)(sw)) in the Indian sector of the Southern Ocean during austral summer. pCO2sw was negatively correlated with total phytoplankton and diatom abundances, as estimated from pigment signatures, in the zone south of the Antarctic Circumpolar Current; however, pCO(2)(sw) was not correlated with haptophyte abundance. Additionally, a stronger correlation was found between pCO(2)(sw) and total phytoplankton NPP than between chlorophyll a concentration...
Tipo: Text
Palavras-chave: Phytoplankton community composition; Diatoms; Southern Ocean; Net primary productivity; Carbon dioxide.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00676/78836/81084.pdf

Maitrise de la culture de masse de la diatomée Skeletonema costatum en système ouvert et continu sur un milieu en "eau de mer"
Provedor de dados: 5
Autores: Brossard, Nicolas; Hussenot, Jerome.
Une culture extérieure en masse de la diatomée Skeletonema costatum, en système ouvert et continu, a été réalisée en automne 1996, au marais expérimental du CREMA I'Houmeau. Le but était d'apporter une nourriture complémentaire aux huîtres en période d'affinage.
Tipo: Text
Palavras-chave: Phytoplancton; Microalgues; Diatomées; Skeletonema costatum; Culture de masse; Culture continue; Affinage d'huîtres; Phytoplankton; Diatoms; Skeletonema costatum; Mass culture; Continuous culture; Oyster fattening.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00020/13117/10126.pdf

On the interest of using field primary production data to calibrate phytoplankton rate processes in ecosystem models
Provedor de dados: 5
Autores: Grangere, Karine; Lefebvre, Sebastien; Menesguen, Alain; Jouenne, Fabien.
In many ecosystem models based on empirical formulations, parameters generally are calibrated in order to achieve the best fit between measured and simulated chlorophyll a standing stocks. An accurate calibration of rate processes as primary production rarely is taken into account. In this paper, we test the usefulness of calibration of phytoplankton photosynthetic processes in an ecosystem model using field primary production data. We used 18 months of photosynthetic process data from the Baie des Veys ecosystem (Normandy, France). Five empirical formulations of photosynthesis-irradiance curve models amongst the most widely used were tested. In each formulation, the variability of photosynthetic parameters (i.e. the light-saturated rate of photosynthesis...
Tipo: Text
Palavras-chave: Baie des Veys; Normandy; France; Diatoms; Chlorophyll a to carbon ratio; Parameter optimisation; Mechanistic formulations; Empirical formulations; Photosynthesis irradiance curve.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6810.pdf

Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years
Provedor de dados: 5
Autores: Crosta, X; Shemesh, A; Etourneau, J; Yam, R; Billy, I; Pichon, Jj.
Most high-southern latitude records of carbon and nitrogen isotopic ratios and elemental ratios are from the Antarctic and Polar Front zones, thus hindering a comprehensive view of nutrient cycling in the Southern Ocean. We present, for the first time, two records from the Subantarctic Zone and the southern Subtropical Zone of the Indian Ocean. These records provide a latitudinal transect covering the main oceanographic systems of the Southern Ocean. Carbon and nitrogen content of the diatom-bound organic matter increases during the last glacial in the Antarctic and Subantarctic zones but does not show a clear climate-related signal in the Subtropical Zone. Comparison of these records with sea-surface temperatures reconstructed at the core locations and...
Tipo: Text
Palavras-chave: Diatoms; Nutrient cycling; Southern Ocean.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00230/34075/32543.pdf

Diatom response to oceanographic and climatic changes in the Congo fan area, equatorial Atlantic Ocean, during the last 190ka BP
Provedor de dados: 5
Autores: Hatin, T.; Crosta, X.; Le Herisse, A.; Droz, L.; Marsset, Tania.
Changes in siliceous productivity in the eastern Equatorial Atlantic Ocean, off the Western African margin, over the last several glacial cycles have been either related to global-to-regional oceanographic changes (upwelling intensity) or climate changes (precipitation and river discharge). Based on diatom assemblages in core KZAI-02, located to the south of the mouth of the Congo River, integrated with a selection of geochemical proxies, we show that siliceous productivity in the southeastern Angola Basin responded to non-linear interactions between both oceanographic and climate changes over the last 190,000 years. High diatom accumulation rates were recorded in the middle part of MIS 6, in cold substage MIS 5d and in MIS 3-2. During these intervals,...
Tipo: Text
Palavras-chave: Diatoms; Productivity; Late quaternary; Millennial time scale; Congo fan area.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00363/47402/47394.pdf

The fate of diatom valves in the Subantarctic and Polar Frontal Zones of the Southern Ocean: Sediment trap versus surface sediment assemblages
Provedor de dados: 5
Autores: Rigual-hernandez, Andres S.; Trull, Thomas W.; Bray, Stephen G.; Armand, Leanne K.
An array of deep ocean sediment traps was initiated in 1997 within the Australian sector of the Southern Ocean, and serviced annually for over a decade (the Subantarctic site is ongoing as part of the Southern Ocean Time Series). Here, we expand on previous findings obtained from the shallow traps (~ 1000 m depth) in the Polar Frontal Zone (PFZ) and Subantarctic Zone (SAZ) by examining the chemical composition and diatom assemblages collected by sediment traps deployed at bathypelagic depths in the PFZ (1500 m depth; years 1997–1998, 1999–2000 and 2003–2004) and SAZ (2000 and 3800 m; year 1999–2000). Additionally, the diatom assemblages of the surface sediments below the traps were analyzed to document how the seasonal signal is recorded in the sedimentary...
Tipo: Text
Palavras-chave: Diatoms; POC; Sediment traps; Surface sediments; Subantarctic Zone; Polar Frontal Zone.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00341/45215/44642.pdf

Sea ice diatom contributions to Holocene nutrient utilization in East Antarctica
Provedor de dados: 5
Autores: Panizzo, Virginia; Crespin, Julien; Crosta, Xavier; Shemesh, Aldo; Masse, Guillaume; Yam, Ruth; Mattielli, Nadine; Cardinal, Damien.
Combined high-resolution Holocene δ30Sidiat and δ13Cdiat paleorecords are presented from the Seasonal Ice Zone, East Antarctica. Both data sets reflect periods of increased nutrient utilization by diatoms during the Hypsithermal period (circa 7800 to 3500 calendar years (cal years) B.P.), coincident with a higher abundance of open water diatom species (Fragilariopsis kerguelensis), increased biogenic silica productivity (%BSi), and higher regional summer temperatures. The Neoglacial period (after circa 3500 cal years B.P.) is reflected by an increase in sea ice indicative species (Fragilariopsis curta and Fragilariopsis cylindrus, up to 50%) along with a decrease in %BSi and δ13Cdiat (&lt; −18‰ to −23‰). However, over this period, δ30Sidiat data show an...
Tipo: Text
Palavras-chave: Diatoms; Silicon isotopes; Diatom bound carbon isotopes; Seasonal ice zone; Holocene; Southern Ocean.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00290/40157/39098.pdf

Modélisation écologique tridimensionnelle (3D) de la baie de Seine (Manche, France)
Provedor de dados: 5
Autores: Cugier, Philippe; Ménesguen, Alain; Guillaud, Jean-francois.
A three dimensional (3D) ecological model is developed and applied to the "baie de Seine" area. It consists of a 3D model for hydrodynamics and port (SiAM3D) coupled to an ecological model simulating nutrient cycles (nitrogen, phosphorus, silicon) and two phytoplanktonic classes (diatoms and flagellates). The model is validated by confronting simulations with nine year long series of measurements and then used to better understand the ecosystem functioning. It especially allows to show the role of the proportion of silicon with regard to nitrogen and phosphorus in the summer loadings of the Seine river on the more or less strong presence of flagellates in the river plume. The model was also used to test various hypotheses of reduction of nitrogen loading...
Tipo: Text
Palavras-chave: Modèle 3D; Éléments nutritifs; Diatomées; Flagellés; Baie de Seine; 3D model; Nutrients; Diatoms; Flagellates; Baie de Seine.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00479/59101/61739.pdf

Coastal phytoplankton community dynamics and coexistence driven by intragroup density-dependence, light and hydrodynamics
Provedor de dados: 5
Autores: Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle.
Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic...
Tipo: Text
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf

The last occurrence of Proboscia curvirostris in the North Atlantic marine isotope stages 9-8
Provedor de dados: 5
Autores: Koc, N; Labeyrie, L; Manthe, S; Flower, Bp; Hodell, Da; Aksu, A.
Well-preserved diatoms are present in high sedimentation rate Pleistocene cores retrieved on ocean Drilling Program (ODP) Legs 151, 152, 162 and IMAGES cruises of RN Marion Dufresne from the North Atlantic. Investigation of the stratigraphic occurrence of diatom species shows that the youngest diatom event observed in the area is the last occurrence (LO) of Proboscia curvirostris (Jouse) Jordan and Priddle. P. curvirostris is a robust species that can easily be identified in the sediments, and therefore can be a practical biostratigraphic tool. We have mapped its: areal distribution, and found that it stretches from 40 degreesN to 80 degreesN in the North Atlantic. Further, we have correlated the LO P. curvirostris to the oxygen isotope records of six...
Tipo: Text
Palavras-chave: Biostratigraphy; North Atlantic; Diatoms; Pleistocene; Paleoceanography; Isotope stratigraphy; Oxygen.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00221/33210/31708.pdf

Quaternary magnetic and oxygen isotope stratigraphy in diatom-rich sediments of the southern Gardar Drift (IODP Site U1304, North Atlantic)
Provedor de dados: 5
Autores: Xuan, Chuang; Channel, James E. T.; Hodell, David A.
The sediment sequence from Integrated Ocean Drilling Program (IODP) Site U1304 (53 degrees 03.40'N, 33 degrees 31.78'W; water depth, 3024 m) on the southern Gardar Drift, North Atlantic Ocean, covers the last similar to 1.8 Myr with a mean sedimentation rate of similar to 15 cm/kyr. At Site U1304, paleomagnetic directional and relative paleointensity (RPI) records have been generated for the last similar to 1.5 Myr, and benthic oxygen isotope data for the last similar to 1 Myr. The age model for Site U1304 was established by matching 6180 and RPI data to calibrated reference records. Prominent intervals of diatom mats at Site U1304 are associated with the latter stages of interglacial marine isotope stages (MIS) 9, 11, 13, 15, 21, 27 and 35, and with the...
Tipo: Text
Palavras-chave: Quaternary; North Atlantic; Relative paleointensity; Magnetic excursions; Oxygen isotopes; Diatoms; IODP Site U1304.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00421/53238/83373.pdf

β-N-methylamino-l-alanine (BMAA) and isomers: Distribution in different food web compartments of Thau lagoon, French Mediterranean Sea
Provedor de dados: 5
Autores: Reveillon, Damien; Abadie, Eric; Sechet, Veronique; Masseret, Estelle; Hess, Philipp; Amzil, Zouher.
The neurotoxin BMAA (β-N-methylamino-l-alanine) and its isomer DAB (2,4-diaminobutyric acid) have been detected in seafood worldwide, including in Thau lagoon (French Mediterranean Sea). A cluster of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with BMAA, has also been observed in this region. Mussels, periphyton (i.e. biofilms attached to mussels) and plankton were sampled between July 2013 and October 2014, and analyzed using HILIC-MS/MS. BMAA, DAB and AEG (N-(2-aminoethyl)glycine) were found in almost all the samples of the lagoon. BMAA and DAB were present at 0.58 and 0.83, 2.6 and 3.3, 4.0 and 7.2 μg g−1 dry weight in plankton collected with nets, periphyton and mussels, respectively. Synechococcus sp., Ostreococcus...
Tipo: Text
Palavras-chave: BMAA; Diatoms; Chaetoceros sp.; Seston; Mytilus galloprovincialis; HILIC-MS/MS.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00275/38607/37192.pdf

Late spring bloom development of pelagic diatoms in Baffin Bay
Provedor de dados: 5
Autores: Lafond, Augustin; Leblanc, Karine; Queguiner, Bernard; Moriceau, Brivaela; Leynaert, Aude; Cornet, Veronique; Legras, Justine; Ras, Josephine; Parenteau, Marie; Garcia, Nicole; Babin, Marcel; Tremblay, Jean-eric.
The Arctic Ocean is particularly affected by climate change, with changes in sea ice cover expected to impact phytoplankton primary production. During the Green Edge expedition, the development of the late spring-early summer diatom bloom was studied in relation with the sea ice retreat by multiple transects across the marginal ice zone. Biogenic silica concentrations and uptake rates were measured. In addition, diatom assemblage structures and their associated carbon biomass were determined, along with taxon-specific contributions to total biogenic silica production using the fluorescent dye PDMPO. Results indicate that a diatom bloom developed in open waters close to the ice edge, following the alleviation of light limitation, and extended 20-30 km...
Tipo: Text
Palavras-chave: Diatoms; Spring bloom; Sea ice; Community composition; Baffin Bay; Arctic.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00615/72752/72021.pdf

Contribution aux recherches ecologiques sur les claires a huitres du bassin de Marennes-Oleron
Provedor de dados: 5
Autores: Moreau, Jean.
Tipo: Text
Palavras-chave: Ecology; Biology; Navicula ostrearia B.; Diatoms; Water quality; Oyster pond; Oyster culture.
Ano: 1970
URL: http://archimer.ifremer.fr/doc/1970/publication-2231.pdf

Realized niche analysis of phytoplankton communities involving HAB: Phaeocystis spp. as a case study
Provedor de dados: 5
Autores: Karasiewicz, Stephane; Breton, Elsa; Lefebvre, Alain; Hernandez Farinas, Tania; Lefebvre, Sebastien.
The link between harmful algal blooms, phytoplankton community dynamics and global environmental change is not well understood. To tackle this challenging question, a new method was used to reveal how phytoplankton communities responded to environmental change with the occurrence of an harmful algae, using the coastal waters of the eastern English Channel as a case study. The great interannual variability in the magnitude and intensity of Phaeocystis spp. blooms, along with diatoms, compared to the ongoing gradual decrease in anthropogenic nutrient concentration and rebalancing of nutrient ratios; suggests that other factors, such as competition for resources, may also play an important role. A realized niche approach was used with the Outlying Mean Index...
Tipo: Text
Palavras-chave: Harmful algae bloom; WitOMI; Subniche; Diatoms; Biotic interaction; Eastern English Channel.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00416/52786/56650.pdf

Biovolume and biomass estimates of key diatoms in the Southern Ocean
Provedor de dados: 5
Autores: Cornet-barthaux, Veronique; Armand, Leanne; Queguiner, Bernard.
Linear measurements of 31 Southern Ocean diatom species or genus groupings are presented and used in the derivation of species-specific biovolume, biomass and surface to volume ratios. Species measurements are in tune with summarised values in the literature and range from 2.6 to 2296 pm in length and 8.5 to 140 pm in diameter. Average cell volume ranged from 63 to 1.43 x 105 mu m(3) and biomass from 10 to 3686 pg C cell(-1), the values being smallest in pennate shaped species and greatest in cylindrical centrics. The 31 species can be divided into 7 small, 12 intermediate and 12 large biomass contributors based on their cell volume and/or their surface to volume ratio. Carbon biomass estimates from biovolume equations are discussed and suggest that future...
Tipo: Text
Palavras-chave: Diatoms; Size measurements; Cell biovolume; Carbon biomass; Kerguelen plateau.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00204/31572/29990.pdf

Reconciling down core anticorrelation of diatom carbon and nitrogen isotopic ratios from the Southern Ocean
Provedor de dados: 5
Autores: Crosta, X; Shemesh, A.
[1] Oceanic nutrient cycling in the Southern Ocean is supposed to have an important impact on glacial-interglacial atmospheric CO(2) changes and global climate. In order to characterize such nutrient cycling over the last two climatic cycles we investigated carbon and nitrogen isotopic ratios of diatom-bound organic matter (delta(13)C(diat) and delta(15)N(diat)- respectively) in two cores retrieved form the Atlantic and Indian sectors of the Antarctic Ocean. The two cores show the same isotopic patterns. The delta(13)C(diat) values are depleted during glacial periods and enriched during interglacial periods, indicating lower productivity during cold times. The delta(15)N(diat) values are enriched during glacial periods and depleted during interglacial...
Tipo: Text
Palavras-chave: Southern Ocean; Paleoceanography; Geochemistry; Diatoms.
Ano: 2002
URL: https://archimer.ifremer.fr/doc/00223/33402/31859.pdf

The Biological Pump and Seasonal Variability of pCO(2) in the Southern Ocean: Exploring the Role of Diatom Adaptation to Low Iron
Provedor de dados: 5
Autores: Person, Roland; Aumont, Olivier; Levy, M.
Iron is known to limit primary production in the Southern Ocean (SO). To cope with the lack of this micronutrient, diatoms, a dominant phytoplankton group in this oceanic region, have been shown in cultures to have developed an original adaptation strategy to maintain efficient growth rates despite very low cellular iron quotas, even in low light conditions. Using a global ocean biogeochemical model, we explored the consequences of this physiological adaptation for the biological pump and the seasonal variability of both surface chlorophyll concentrations and surface partial pressure of carbon dioxide (pCO(2)) in this key region for global climate. In the model, we implemented a low intracellular Fe:C requirement in the SO for diatoms uniquely. This...
Tipo: Text
Palavras-chave: Southern Ocean; Diatoms; Physiological adaptation; Biological pump; PCO(2); Seasonal variability.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00673/78490/80817.pdf

Linking ocean biogeochemical cycles and ecosystem structure and function: results of the complex SWAMCO-4 model
Provedor de dados: 5
Autores: Pasquer, B; Laruelle, G; Becquevort, S; Schoemann, V; Goosse, H; Lancelot, C.
We present results obtained with SWAMCO-4, a complex model of the marine planktonic system calculating C, N, P, Si, Fe cycling within the upper ocean, the export production and the exchange of CO2 between the ocean and atmosphere. The model, constrained by physical, chemical and biological (grazing, lysis) controls, explicitly details the dynamics of four relevant phytoplankton functional groups with respect to C, N, P, Si, Fe cycling and climate change. Those are diatoms, pico/nano phytoplankton, coccolithophorids, and Phaeocystis spp. whose growth regulation by light, temperature and nutrients has been obtained based on a comprehensive analysis of literature reviews on these taxonomic groups. The performance of SWAMCO-4 is first evaluated in a 1D...
Tipo: Text
Palavras-chave: Ecological modelling; Diatoms; Pico/nanophytoplankton; Coccolithophorids; Phaeocystis spp.; Iron; Air-sea CO2 fluxes; Global ocean; Antarctic ocean; North Atlantic.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00232/34302/32677.pdf

High-latitude forcing of diatom productivity in the southern Agulhas Plateau during the past 350 kyr
Provedor de dados: 5
Autores: Romero, O. E.; Kim, J. -h.; Barcena, M. A.; Hall, I. R.; Zahn, R.; Schneider, R.
The hydrography of the Indian-Atlantic Ocean gateway has been connected to high-latitude climate dynamics by oceanic and atmospheric teleconnections on orbital and suborbital timescales. A wealth of sedimentary records aiming at reconstructing the late Pleistocene paleoceanography around the southern African continent has been devoted to understanding these linkages. Most of the records are, however, clustered close to the southern South African tip, with comparatively less attention devoted to areas under the direct influence of frontal zones of the Southern Ocean/South Atlantic. Here we present data of the composition and concentration of the diatom assemblage together with bulk biogenic content and the alkenone-based sea surface temperature (SST)...
Tipo: Text
Palavras-chave: Agulhas; SST; Diatoms; Fronts; Silica; Southern Ocean.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00294/40555/39440.pdf

Composition of diatom communities and their contribution to plankton biomass in the naturally iron fertilized region of Kerguelen in the Southern Ocean
Provedor de dados: 5
Autores: Lasbleiz, Marine; Leblanc, Karine; Armand, Leanne K.; Christaki, Urania; Georges, Clement; Obernosterer, Ingrid; Queguiner, Bernard.
In the naturally iron-fertilized surface waters of the northern Kerguelen Plateau region, the early spring diatom community composition and contribution to plankton carbon biomass were investigated and compared with the High Nutrient Low Chlorophyll (HNLC) surrounding waters. The large iron-induced blooms were dominated by small diatom species belonging to the genera Chaetoceros (Hyalochaete) and Thalassiosira, which rapidly responded to the onset of favorable light-conditions in the meander of the Polar Front. In comparison, the iron-limited HNLC area was typically characterized by autotrophic nanoeukaryote-dominated communities and by larger and more heavily silicified diatom species (e.g. Fragilariopsis spp.). Our results support the hypothesis that...
Tipo: Text
Palavras-chave: Diatoms; Carbon biomass; Plankton community structure; Natural iron fertilization; Southern Ocean.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00347/45850/45512.pdf

Assessing Alternative Microscopy-Based Approaches to Species Abundance Description of Intertidal Diatom Communities
Provedor de dados: 5
Autores: Ribeiro, Lourenço; Brotas, Vanda; Hernandez Farinas, Tania; Jesus, Bruno; Barille, Laurent.
Diatoms usually dominate microphytobenthic biofilms in coastal and estuarine intertidal environments. Yet, functional studies on biofilms often skip species analysis because benthic diatoms are notoriously difficult to extract from sediments and challenging to identify at that taxonomic level. Valid, less time-consuming alternatives would surely be welcomed and increase the inclusion of community structure information in microphytobenthos (MPB) ecophysiological studies. Starting with an original 181-species abundances matrix (OSM), obtained during a 2-year spatial–temporal survey in a Tagus Estuary intertidal flat with contrasting sediment textures, the current study assessed the effectiveness of several approaches to species abundances analysis. The...
Tipo: Text
Palavras-chave: Diatoms; Community structure; Intertidal flats; Microphytobenthos; Multivariate analysis; Taxonomic sufficiency.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00610/72187/70963.pdf

Novel Widespread Marine Oomycetes Parasitising Diatoms, Including the Toxic Genus Pseudo-nitzschia: Genetic, Morphological, and Ecological Characterisation
Provedor de dados: 5
Autores: Garvette, Andrea; Nezan, Elisabeth; Badis, Yacine; Bilien, Gwenael; Arce, Paola; Bresnan, Eileen; Gachon, Claire M. M.; Siano, Raffaele.
Parasites are key drivers of phytoplankton bloom dynamics and related aquatic ecosystem processes. Yet, the dearth of morphological and molecular information hinders the assessment of their diversity and ecological role. Using single-cell techniques, we characterise morphologically and molecularly, intracellular parasitoids infecting four potentially toxin-producing Pseudo-nitzschia and one Melosira species on the North Atlantic coast. These sequences define two, morphologically indistinguishable clades within the phylum Oomycota, related to the genera of algal parasites Anisolpidium and Olpidiopsis and the diatom parasitoid species Miracula helgolandica. Our morphological data are insufficient to attribute either clade to the still unsequenced genus...
Tipo: Text
Palavras-chave: Pseudo-nitzschia; Diatoms; Marine oomycetes; Plankton parasites; Single-cell analysis; Metabarcoding.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00470/58135/60593.pdf

Regulation of the Phytoplankton Heme b Iron Pool During the North Atlantic Spring Bloom
Provedor de dados: 5
Autores: Louropoulou, Evangelia; Gledhill, Martha; Browningi, Thomas J.; Desai, Dhwani K.; Barraqueta, Jan-lukas Menzel; Tonnard, Manon; Sarthou, Geraldine; Planquette, Helene; Bowie, Andrew R.; Schmitz, Ruth A.; Laroche, Julie; Achterberg, Eric P.
Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (&lt; 1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (&gt; 0.7 mu m) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median =...
Tipo: Text
Palavras-chave: Heme b; North Atlantic; Phytoplankton; Diatoms; Iron; Limitation; GEOTRACES; GEOVIDE.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00508/61940/66029.pdf

BMAA et cyanotoxines : microalgues productrices et niveaux d’accumulation dans les organismes marins
Provedor de dados: 5
Autores: Reveillon, Damien.
BMAA (â-N-methylamino-L-alanine) is a non proteinogenic neurotoxic amino acid that has been associated with amyotrophic lateral sclerosis. Its analytical detection is widely debated thus the global production of BMAA by cyanobacteria is questioned. We first aimed at developing an analytical method allowing for highly selective identification of BMAA and isomers, using HILIC chromatography coupled to mass spectrometry. Then, we have cultivated and analyzed more than 50 microalgae (e.g. cyanobacteria, diatoms). Unlike DAB, one of its natural isomer, BMAA was only reported in five diatom species and cannot be accounted as a cyanotoxin anymore. In parallel, we have evaluated the presence of BMAA on the three French coasts. The presence of BMAA in different...
Tipo: Text
Palavras-chave: DAB; Cyanotoxines; CL-SM/SM; Diatomées; Cyanobactéries; Bivalves; BMAA; DAB; Cyanotoxins; LC-MS/MS; Diatoms; Cyanobacteria; Bivalves.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00295/40651/39617.pdf

Use of diatom motility features as endpoints of metolachlor toxicity
Provedor de dados: 5
Autores: Coquille, Nathalie; Jan, Gwilherm; Moreira, Aurelie; Morin, Soizic.
Many recent ecotoxicological studies suggest a relationship between freshwater contamination and increasing abundances of motile diatoms (potentially able to move). The capacity to escape would present advantages to species in polluted environments. However, actual motility as a response to toxicants had not been described and required experimental validation. We designed a specific experiment to assess how a field-isolated diatom (Gomphonema gracile) distributes energy to in situ resistance (increased population growth or photosynthesis) and escape (behavioral changes), when exposed to increasing concentrations of the herbicide metolachlor. We report here the dose-time dependent responses of G. gracile populations. They coped with low contamination by...
Tipo: Text
Palavras-chave: Diatoms; Physiology; Behavior; Pesticide exposure; Motility; CASA.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00254/36521/35081.pdf

Atlas des Diatomophycées des côtes françaises et des aires marines adjacentes
Provedor de dados: 5
Autores: Paulmier, Gerard.
This Atlas puts the list of main diatoms from phytoplanktonic collects carried out in the French  waters and bordering marine areas. A simple key of genera is set up and listed species are illustrated by photographies obtained with light microscope, and by drawings.
Tipo: Text
Palavras-chave: Iconographie list; Mediterranean See; Channel; Atlantic; French coasts; Diatoms; Liste iconographique; Méditerranée; Manche; Atlantique; Côtes françaises; Diatomées; Diatomophycées.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/rapport-2452.pdf

Nanoplastics exposure modulate lipid and pigment compositions in diatoms
Provedor de dados: 5
Autores: Gonzalez-fernandez, Carmen; Le Grand, Fabienne; Bideau, Antoine; Huvet, Arnaud; Paul-pont, Ika; Soudant, Philippe.
The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS–NH2) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 μg mL−1) and a high (5 μg mL−1) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photoprotection mainly at exponential phase. NP also impacted lipid composition of diatoms with a re-adjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly,...
Tipo: Text
Palavras-chave: Diatoms; Nanoplastics; Lipid composition; Pigments.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00611/72283/71083.pdf

Guide pratique à l'usage des analystes du Réseau National de Surveillance du phytoplancton
Provedor de dados: 5
Autores: Nezan, Elisabeth; Piclet, Guy; Grossel, Hubert.
This work is based on optical microscopic photographs. It helps to the identification of the phytoplanktonic organisms from the french coastal zones and to the normalization of the results of microscopic analysis.  1)Dinophyceae and dinoflagellate 2)Bacillariophyceae or diatomophyceae,named diatoms 3)Others classes
Tipo: Text
Palavras-chave: Dinoflagellate; Diatoms; France; Coastal zones; Identification; Phytoplankton.
Ano: 1997
URL: https://archimer.ifremer.fr/doc/00502/61382/65020.pdf

Rapid longitudinal migrations of the filament front off Namibia (SE Atlantic) during the past 70kyr
Provedor de dados: 5
Autores: Romero, O. E.; Crosta, X.; Kim, J. -h.; Pichevin, L.; Crespin, J.
Although productivity variations in coastal upwelling areas are mostly attributed to changes in wind strength, productivity dynamics in the Benguela Upwelling System (BUS) is less straightforward due to its complex atmospheric and hydrographic settings. In view of these settings, past productivity variations in the BUS can be better investigated with downcore sediments representing different productivity regimes. In this study, two sediment cores retrieved at ca. 25°–26°S in the BUS and representing different productivity regimes were studied. By using micropaleontological, geochemical and temperature proxies measured on core MD96-2098, recovered at 2910 m water depth in the bathypelagic zone at 26°S off Namibia, variations of filament front location,...
Tipo: Text
Palavras-chave: Benguela; Diatoms; Millennial and submillennial time scale; Productivity; Sea-surface temperature; SW Atlantic; Upwelling filaments.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00294/40499/39432.pdf

Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic
Provedor de dados: 5
Autores: Cardinal, D; Alleman, Ly; Dehairs, F; Savoye, N; Trull, Tw; Andre, L.
We analyzed delta(29) Si of dissolved silicate for eight water column profiles across the Southern Ocean ( south of Australia in spring 2001) from the Seasonal Ice Zone (SIZ) north to the Subantarctic Zone (SAZ), including the first isotopic compositions measured for Si-depleted seawaters. All profiles display mixed layer enrichments in heavy Si isotopes relative to deep water in accordance with preferential uptake of the light isotope by diatoms. As silicate levels decrease from the SIZ northward across the Polar Front Zone (PFZ) to the SAZ, surface and mesopelagic delta(29) Si signatures generally become progressively heavier, but the most Si-depleted SAZ waters do not exhibit delta(29) Si values heavier than in the PFZ. This intricacy appears to derive...
Tipo: Text
Palavras-chave: Δ29Si; Δ30Si; Diatoms; Spring Southern Ocean; Fractionation factor.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00233/34424/32838.pdf

Plankton community composition in relation to availability and uptake of oxidized and reduced nitrogen
Provedor de dados: 5
Autores: 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

Sea-level changes in Iceland and the influence of the North Atlantic Oscillation during the last half millennium
Provedor de dados: 5
Autores: 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

Diatoms from the southwestern continental slope, South China Sea, and their paleoenvironmental significance since the last glacial times
Provedor de dados: 5
Autores: 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

Insights into nitrogen cycling in the western Gulf of California from the nitrogen isotopic composition of diatom-bound organic matter
Provedor de dados: 5
Autores: 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 &lt;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

Si cycling in transition zones: a study of Si isotopes and biogenic silica accumulation in the Chesapeake Bay through the Holocene
Provedor de dados: 5
Autores: 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

Caractéristiques physiques et chimiques fines des cendres volcaniques : application à la téphrostratigraphie
Provedor de dados: 5
Autores: Jouannic, Gwénolé.
The challenge of this work was to carry out several tephrostratigraphic studies in various sedimentary environments in order to test the efficiency of classical detection methods of tephra layers. First, analysis has been focused on tephra keys, previously studied in known sites, in Belgium and in the Jura Mountains, in order to update data with current analytical techniques. This work was later expanded to sites from eastern French Massif Central, an area with unexploited tephrostratigraphic potential, which offers the possibility to precise the source of cryptotephras identified in the Jura and Switzerland whose origin was uncertain. This work has been carried out in tephras sampled in loess, carbonate maris and peat allowing to discuss conservation...
Tipo: Text
Palavras-chave: Téphra; Jura; Massif Central; Belgique; Diatomées; Imagerie scanner; XRF; Susceptibilité magnétique; Pyroclastites -- Jura (massif); Pyroclastites; Pyroclastites -- Liège (Belgique; Région); Stratigraphie; Téphrochronologie; Tephra; French Massif Central; Belgium; Diatoms; CT Scan; Magnetic susceptibility.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00506/61720/65688.pdf

Do transparent exopolymeric particles (TEP) affect the toxicity of nanoplastics on Chaetoceros neogracile?
Provedor de dados: 5
Autores: 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

The Kinker diatom collection: discovery – exploration – exploitation
Provedor de dados: 16
Autores: 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

Vijf soorten kiezelalgen nieuw voor de Nederlandse oppervlaktewateren
Provedor de dados: 16
Autores: Verweij, G.L.; Oever, A. van den.
Diatoms are a major group of unicellular micro-algae with a silica-based cell wall. They comprise an abundant and highly diverse group of algae which are found in and around all water types. Their lifestyles are various and include planktonic species that live suspended in the water column, while other species grow on substrates such as plants, macroalgae, and rocks. The substrate bound species are categorized in different life forms. For example, epipsammic diatoms are directly adhered to sand grains or other sediment particles and are immobile in contrast to epipelic diatoms, which are more or less motile. This paper concentrates on epiphytic life forms, diatoms that are attached to other plants and algae, including larger diatoms (Barber 1994). Diatoms...
Tipo: Article / Letter to the editor
Palavras-chave: Bacillariophyceae; Diatoms; Achnanthes minuscula; Lyrella sulcifera; Pinnularia quadratarea; Pinnularia latarea; Stauroneis pseudagrestis.
Ano: 2018
URL: http://www.repository.naturalis.nl/record/650243

Impact des perturbations anthropiques sur l'évolution du phytoplancton de la lagune de Boughrara, ( tunisie )
Provedor de dados: 20
Autores: 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

Condiciones del plancton en una estación fija: Puerto El Morro-Playas, Golfo de Guayaquil, 2000-2002
Provedor de dados: 20
Autores: Bonilla Coello, M.A.; Plúas, F.; Camposano, J.
En este estudio se examina la abundancia estructura poblacional y variación temporal del plancton, especialmente de copépodos en el Golfo de Guayaquil, a través de tres años de estudio, en condición no El Niño.
Tipo: Journal Contribution
Palavras-chave: Plankton; Phytoplankton; Abundance; Distribution; Zooplankton; Marine crustaceans; Fixed stations; Population structure; Diatoms; Fish eggs; Fish larvae; Population structure; Plankton; Phytoplankton; Distribution; Zooplankton; Diatoms; Fish larvae; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_5950; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_35773; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_32657; Http://aims.fao.org/aos/agrovoc/c_2924.
Ano: 2002
URL: http://hdl.handle.net/1834/2315

Adición a la microflora de diatomeas de las aguas marinas de Cuba.
Provedor de dados: 20
Autores: Loza, S.; Sánchez, M.; Carmenate, M.; Siqueiros-Beltrones, D.
Se presenta la información sobre la especie de diatomea Campylostylus normannianus  (Greville, 1862) Gerloff, Natour &amp; 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

Plancton alrededor de las Islas Galápagos durante el crucero oceanográfico efectuado en mayo de 2004
Provedor de dados: 20
Autores: Tapia, M.E.; Naranjo, Ch.
El presente trabajo comprende la composición y distribución del plancton en las Islas Galápagos. Para el efecto se establecieron 13 estaciones ubicadas en las secciones 92° - 90° y 89° W, realizadas en mayo del 2004.
Tipo: Journal Contribution
Palavras-chave: Plankton; Community composition; Distribution; Phytoplankton; Zooplankton; Diatoms; Biomass; Cruises; Biomass; Plankton; Distribution; Phytoplankton; Zooplankton; Diatoms; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_5950; Http://aims.fao.org/aos/agrovoc/c_35773; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2006
URL: http://hdl.handle.net/1834/2331

Florecimiento de la diatomea potencialmente tóxica Pseudo-nitzschia cf.  multistriata en aguas cubanas
Provedor de dados: 20
Autores: 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

Distribución cuali-cuantitativa del fitoplancton en el Pacífico sureste (3°16'-31°23'S), durante El Niño 1997-1998
Provedor de dados: 20
Autores: Torres, G.
El objetivo del presente artículo es estudiar la distribución de las concentraciones de clorofila "a" y feopigmentos en diciembre/97 y marzo/98, y cuales serían los indicadores biológicos del fitoplancton que han avanzado con la corriente cálida hacia el sur en diciembre/97, en condiciones de El Niño 97-98, en el Pacífico sudeste exceptuando la región peruana (Fig.1).
Tipo: Journal Contribution
Palavras-chave: Distribution; Phytoplankton; Biomass; Community composition; Diatoms; El Nino phenomena; Oceanographic stations; Chlorophylls; Distribution; Phytoplankton; Biomass; Diatoms; Chlorophylls.
Ano: 1998
URL: http://hdl.handle.net/1834/2393

Distribución del fitoplancton en el Estrecho Bransfield, Bahía Chile y Paso Drake, durante el verano austral 1998 (Antártida)
Provedor de dados: 20
Autores: 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

Development of Sedimentary Environment in the Northeastern South China Sea Since the Last Glacial Stage.
Provedor de dados: 20
Autores: 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

El empleo de los colorantes para el estudio citológico de las diatomeas
Provedor de dados: 20
Autores: Ferrando, H.J.
La finalidad de este trabajo es estudiar la citología de las diatomeas post-mortem para el conocimiento de sus organizaciones estructurales internas, mediante el uso de colorantes de utilización corriente en las técnicas histológicas, introduciendo las modificaciones que consideramos oportunas para su aplicación.
Tipo: Journal Contribution
Palavras-chave: Diatoms; Colorimetric techniques; Diatoms; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 1958
URL: http://hdl.handle.net/1834/3027

Productividad del fitoplancton en la Bahía de Santa Elena, Ecuador durante mayo del 2006
Provedor de dados: 20
Autores: Tapia, M.E.
Se presentan las investigaciones de clorofila a contajes celulares y análisis cualitativos (red 50u), que utilizados simultáneamente aportaron valiosa información ecológica sobre la comunidad del fitoplancton realizadas en 27 estaciones en la bahía de Santa Elena efectuado en mayo de 2006. Se identificaron 50 especies en muestras de agua y 62 especies en muestras de red (50u), en la comunidad del fitoplancton. Las diatomeas fueron dominantes y en menor concentración los dinoflagelados, cocolitofóridos, cianobacterias y tintinnidos. Las especies de mayor ocurrencia en el área en estudio fueron Thalassiosira subtilis y Pseudo-nitzschia delicatissima observadas en los contajes celulares. En muestras de red (50u), se registraron especies típicas de ambiente...
Tipo: Journal Contribution
Palavras-chave: Phytoplankton; Chlorophylls; Biological production; Diatoms; Phytoplankton; Biological production; Chlorophylls; Diatoms; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_36649; Http://aims.fao.org/aos/agrovoc/c_1577; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2009
URL: http://hdl.handle.net/1834/3349

Diagnóstico del plancton en el estuario de San Lorenzo en agosto 2006 (Esmeraldas-Ecuador)
Provedor de dados: 20
Autores: 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

Especies planctónicas marinas como bioindicadoras de masas de agua frente a la costa ecuatoriana durante el evento El Niño 2009-2010
Provedor de dados: 20
Autores: Cruz, M.; Tapia, M.E.; Naranjo, Ch.
Con la finalidad de determinar la influencia del evento El Niño 2009-2010 que se dsarrolló en elas regiones Niño 1+2 y 3.4, en base a los organismos indicadores de masas de aguas para determinar la intensidad y efectos en la costa ecuatoriana, se utilizaron cinco grupos de organismos planctónicos: Diatomeas, Dinoflagelados, Quetognatos, Pterópodos, Heterópodos y las concentraciones de clorofila a antes, durante y después del evento El Niño 2009-2010. En el primer trimestre del 2009 se registró una alta producción primaria, mientras que desde septiembre a noviembre se observó la más baja productividad del mar, en las estaciones fijas La Libertad como en Manta.En la estación fija de La Libertad, durante todo el 2009 predominaron especies de fitoplancton que...
Tipo: Journal Contribution
Palavras-chave: Phytoplankton; Zooplankton; Indicator species; Diatoms; Primary production; El Nino phenomena; Water masses.
Ano: 2010
URL: http://hdl.handle.net/1834/4213

Variación estacional de las especies del microbentos de la Bahía Manta en la costa ecuatoriana, durante 2011
Provedor de dados: 20
Autores: Gualancañay, E.
Durante la estación lluviosa (marzo 2011), las especies identificadas de la microfauna bentónica en el área de la bahía de Manta son: Bulimina pulchella, Buliminella elegantissima, Cibicides bertheloti, F. boueana, Nonion pizarrense, Quinqueloculina lamarckiana, Rotalia beccarii, Lagena striata y la única especie de la microflora béntica fue Coscinodiscus perforatus y corresponden a la provincia zoogeográfica panameña propuesta por Boltovskoy (1965) y confirmada por Boltosvskoy y Gualancañay (1975) y Gualancañay (1986). Durante la fase seca (septiembre 2011), la microflora béntica estuvo representada por dos especies de diatomeas bénticas: Cocinodiscus perforatus y Polymixus coronalis. En cambio la microfauna bentónica se la halló distribuida en el área de...
Tipo: Journal Contribution
Palavras-chave: Seasonal variations; Microorganisms; Benthos; Diatoms; Biogeography; Rainy season; Dry season.
Ano: 2012
URL: http://hdl.handle.net/1834/4708

Aspectos oceanográficos del plancton y su relación con el frente ecuatorial, durante septiembre del 2011
Provedor de dados: 20
Autores: Tapia, M.E.; Naranjo, Ch.
El presente trabajo comprende la composición y distribución del plancton en las Islas Galápagos. Para el efecto se establecieron 12 estaciones ubicadas en las secciones 83°- 86°-89° y 92°W, realizadas en septiembre del 2011. Se identificaron 71 especies de fitoplancton en muestras de red (50µ). Las diatomeas fueron dominantes y en menor concentración se observaron los Dinoflagelados, Cocolitofóridos, Silicoflagelados, Cianobacterias y Tintínnidos. En las muestras de red se observaron Chaetoceros eibenii, Rhizosolenia imbricata, Thalassiosira subtilis, Proboscia alata y Planktoniella sol características del Frente Ecuatorial en la sección 86°W y 02° sur. En zooplancton se registraron 17 taxa zooplanctónicas destacándose los grupos de Radiolarios 47.5%,...
Tipo: Journal Contribution
Palavras-chave: Composition; Distribution; Plankton; Diatoms; Abundance; Cruises.
Ano: 2012
URL: http://hdl.handle.net/1834/4705

Composición, distribución y abundancia del plancton en el estuario de San Lorenzo, Esmeraldas - Ecuador
Provedor de dados: 20
Autores: Naranjo, Ch.; Tapia, M.E.
El presente trabajo es una contribución al estudio del plancton estuarino presente en el área comprendida del Canal de San Lorenzo, provincia de Esmeraldas, para lo cual existe poca información sobre este tema.
Tipo: Journal Contribution
Palavras-chave: Distribution; Composition; Abundance; Plankton; Phytoplankton; Zooplankton; Ichthyoplankton; Diatoms; Biomass; Distribution; Plankton; Phytoplankton; Zooplankton; Biomass; Diatoms; Http://aims.fao.org/aos/agrovoc/c_35773; Http://aims.fao.org/aos/agrovoc/c_5950; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2002
URL: http://hdl.handle.net/1834/2277

Composición y variación estacional del fitoplancton, zooplancton y microbentos en el estuario interior del Golfo de Guayaquil, durante el año 2003
Provedor de dados: 20
Autores: Gualancañay, E.; Tapia, M.E.; Naranjo, Ch.
El presente trabajo comprende el estudio de la distribution cualitativa y cuantitativa del fitoplancton en el Golfo de Guayaquil, durante dos épocas: Húmeda y seca. El propósito del presente trabajo con respecto al zooplankton está orientado a conocer los cambios en la composición, abundancia y diversidad del zooplancton y en particular el Phyllum Chaetognatha con el objetivo de relacionar la distribución de las especies de Quetognatos con los parámetros físicos. En lo relacionado al estudio del microbentos, se pretende estudiar la composición específica y la abundancia relativa de las especies de la microflora béntica y de la microfauna bentónica y su relación con factores ambientales.
Tipo: Journal Contribution
Palavras-chave: Community composition; Seasonal variations; Phytoplankton; Diatoms; Biomass; Zooplankton; Microorganisms; Benthos; Geographical distribution; Estuaries; Phytoplankton; Biomass; Zooplankton; Benthos; Geographical distribution; Estuaries; Diatoms; Microorganisms; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_878; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_32657; Http://aims.fao.org/aos/agrovoc/c_4807.
Ano: 2004
URL: http://hdl.handle.net/1834/2283

Variación estacional del fitoplancton en una estación fija en el estero del Muerto durante 1999-2000-2001
Provedor de dados: 20
Autores: Tapia, M.E.
El objetivo del presente estudio es conocer la variación estacional de las especies del fitoplancton y su relación con las condiciones ambientales durante el período en estudio.
Tipo: Journal Contribution
Palavras-chave: Seasonal variations; Phytoplankton; Chlorophylls; Diatoms; Environmental conditions; Cell counters; Estuaries; Fixed stations; Marshes; Biomass; Phytoplankton; Estuaries; Biomass; Chlorophylls; Diatoms; Environmental conditions; Marshes; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_1577; Http://aims.fao.org/aos/agrovoc/c_32657; Http://aims.fao.org/aos/agrovoc/c_32980; Http://aims.fao.org/aos/agrovoc/c_4631.
Ano: 2006
URL: http://hdl.handle.net/1834/2310

Estudio de la comunidad fitoplanctónica en el estuario interior de Esmeraldas, Ecuador durante mayo de 2002
Provedor de dados: 20
Autores: Tapia, M.E.
El presente trabajo tiene por finalidad determinar la composición, abundancia y distribution de las especies que se encuentran en los ríos de la ciudad de Esmeraldas.
Tipo: Journal Contribution
Palavras-chave: Chlorophylls; Phytoplankton; Abundance; Diatoms; Species diversity; Cell counters; Estuaries; Community composition; Distribution; Phytoplankton; Estuaries; Distribution; Chlorophylls; Diatoms; Species diversity; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_2673; Http://aims.fao.org/aos/agrovoc/c_35773; Http://aims.fao.org/aos/agrovoc/c_1577; Http://aims.fao.org/aos/agrovoc/c_32657; Http://aims.fao.org/aos/agrovoc/c_33954.
Ano: 2003
URL: http://hdl.handle.net/1834/2402

Relación fitoplancton-zooplancton en el Pacífico Ecuatorial (Ecuador), durante septiembre 2001
Provedor de dados: 20
Autores: Torres, G.; Mero, M.; Calderón, T.; Franco, V.; Salazar, E.
El presente trabajo es una contribución al conocimiento de la bio-oceanografía del mar ecuatoriano, forma parte del proyecto de Monitoreo de las condiciones oceanográficas en el mar ecuatoriano y su relación con eventos de El Niño, realizadas en el B/I ORION del Instituto Oceanográfico de la Armada (INOCAR) en septiembre-octubre 2001, como un aporte a la comunidad científica.
Tipo: Journal Contribution
Palavras-chave: Phytoplankton; Diatoms; Zooplankton; Biological production; Upwelling; Population density; Cruises; Abundance; Geographical distribution; Biological production; Geographical distribution; Phytoplankton; Zooplankton; Population density; Diatoms; Http://aims.fao.org/aos/agrovoc/c_36649; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_6112; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 2004
URL: http://hdl.handle.net/1834/2297

Importancia ecológica del fitoplancton durante El Niño 1991-1993, en el Pacífico Ecuatorial (Ecuador)
Provedor de dados: 20
Autores: Torres, G.
El objetivo del estudio fue determinar su importancia ecológica y diversidad de los principales grupos del fitoplancton durante El Niño 1991-1992, en tres cruceros realizados en la época cálida-húmeda del ecosistema del Pacífico Ecuatorial (1991, 1992 y 1993).
Tipo: Journal Contribution
Palavras-chave: Marine ecology; Phytoplankton; Upwelling; Chlorophylls; Diatoms; Biological production; El Nino phenomena; Oceanographic stations; Multiship expeditions; Phytoplankton; Biological production; Marine ecology; Chlorophylls; Diatoms.
Ano: 2006
URL: http://hdl.handle.net/1834/2301

Variabilidad estacional del fitoplancton y su relación con los parámetros ambientales en el estuario interior de Esmeraldas durante los años 2004-2005
Provedor de dados: 20
Autores: Tapia, M.E.
Se colectaron y analizaron un total de 96 estaciones distribuidas en cinco áreas de la Provincia de Esmeraldas durante los años 2004-2005. Se elaboraron gráficos de las especies (muestras de red de 50 µ) y la relación con los parámetros físicos y químicos. En la comunidad del fitoplancton presentó una variabilidad en la composición de especies, especialmente en el Terminal Petrolero durante septiembre del 2004 y disminuye en abril del 2005, la mayor densidad poblacional fue para el grupo de diatomeas. Las principales especies en el ambiente marino estuarino Climacosphenia monoligera, Pseudo-nitzschia paradoxa, Thalassiotrix frauenfeldii, Terpsinoe musica, Coscinodiscus excentricus. Las especies representativas en el ambiente marino Navicula tuscula,...
Tipo: Journal Contribution
Palavras-chave: Phytoplankton; Diatoms; Pollution; Estuaries; Station lists; Distribution.
Ano: 2012
URL: http://hdl.handle.net/1834/4653

Diatomeas y silicoflagelados del fitoplancton del Golfo de Guayaquil: II edición
Provedor de dados: 20
Autores: Jiménez, R.
Fueron estudiadas 44 muestras de plancton, de las cuales 189 especies y variedades de diatomeas y silicoflagelados fueron identificados. La mayoría de las especies son registradas por primera vez para el mar ecuatoriano. Las diatomeas centrales (centricae) es el más importante orden en el Plancton del Golfo, mientras las diatomeas pennales (Pennatae) es el orden más predominante en la región estuarina inferior. El análisis sistemático de cada especie incluye descripción, dibujos, medidas y referencias bibliográficas. Datos de temperatura, salinidad, clorofilas y producción primaria del Golfo de Guayaquil son consideradas como condiciones hidrobiológicas del área.
Tipo: Journal Contribution
Palavras-chave: Diatoms; Phytoplankton; Phytoplankton; Diatoms; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_32657.
Ano: 1983
URL: http://hdl.handle.net/1834/2104

La clorofila a como un indicador biológico en las estaciones fijas durante el evento La Niña 1999-2000
Provedor de dados: 20
Autores: Tapia, M.E.; Naranjo, Ch.
Se analizaron un total de 58 muestras en La Libertad y 54 muestras de agua marina costera en Manta durante el evento La Niña 1999-2000. Se elaboraron mapas de distribución de clorofila a, y la relación con los parámetros físicos y químicos. Las condiciones físicas durante el desarrollo del evento La Niña 1999-2000, no siguieron un patrón definido, sino que han presentado características particulares para cada región del Océano Pacífico Sur. En Ecuador se observó que la productividad biológica aumentó considerablemente en La Libertad durante el año 2000 existiendo la presencia de afloramientos con núcleos de clorofila a, altas concentraciones celulares e incremento de la abundancia relativa de importantes especies de diatomeas.
Tipo: Journal Contribution
Palavras-chave: Chlorophylls; Biological production; Upwelling; El Nino phenomena; Marine water; Species diversity; Diatoms.
Ano: 2010
URL: http://hdl.handle.net/1834/4214

Scanning electron microscope studies on some species of the centric diatom genera &lt;i&gt;Thalassiosira&lt;/i&gt; and &lt;i&gt;Coscinodiscus&lt;/i&gt;
Provedor de dados: 27
Autores: Somers, D.
By means of a scanning electron microscope, the submicroscopic structure of four &lt;i&gt;Thalassiosira&lt;/i&gt; species and two &lt;i&gt;Coscinodiscus&lt;/i&gt; species is studied. Five of these taxa are more or less similar in the arrangement of the areoles; the sixth one is aberrant. Besides the description of each species and the description of the submicroscopic structure of the auxospore of &lt;i&gt;Thalassiosira nordenskiöldii&lt;/i&gt;, a classification is given of the six taxa studied.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Electron microscopy; Microscopy; Coscinodiscus; Thalassiosira.
Ano: 1972
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3457

A model of nematode dynamics in the Westerschelde Estuary
Provedor de dados: 27
Autores: Li, J.; Vincx, M.; Herman, P.M.J.
We developed a time dynamic model to investigate the temporal dynamics of nematode community in the brackish zone of the Westerschelde Estuary. The biomass of four nematode feeding groups observed from March 1991 to February 1992 is used to calibrate the model. Using environmental data as the input, the model predicts the temporal modification and interrelation of four nematode feeding groups. Nematodes achieve a dominant position in the community because of their lower loss rate (in respiration, excretion and natural death). Predators which are deposit-feeding macrobenthos control the variations of dominant nematodes, such as omnivores and non-selective deposit feeders. Food availability causes modification only for rare nematodes such as epigrowth...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Ecology; Food; Light; Marine nematodes; Meiobenthos; Population dynamics; Predation; Respiration; Temperature; Nematoda [Nematodes].
Ano: 1996
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7284

Paleolimnological studies of Laguna Chica of San Pedro (VIII Region): Diatoms, hydrocarbons and fatty acid records
Provedor de dados: 97
Autores: URRUTIA,ROBERTO; KOEN,SABBE; CRUCES,FABIOLA; POZO,KARLA; BECERRA,JOSE; ARANEDA,ALBERTO; VYVERMAN,WIM; PARRA,OSCAR.
Diatom, hydrocarbons and fatty acid sedimentary records were used for reconstructing the recent (last 150 years) palaeolimnological history of Laguna Chica of San Pedro (Concepción, VIII Región, Chile). Cluster analyses (Constrained Incremental Sum of Squares) on the diatom data revealed three distinct periods. The first period (1883-1940's) showed a pronounced increase in sedimentation rate and a slight increase in organic matter accumulation. In this period, eutrophic species (Aulacoseira granulata and Staurosira construens) became increasingly dominant. From the 1940s until the 1970s the diatom signal is more equivocal: after the initial decrease in the relative abundance of A. granulata and S. construens their numbers fluctuate without a clear pattern....
Tipo: Journal article
Palavras-chave: Diatoms; Hydrocarbons; Fatty acids; Paleolimnology; Land use.
Ano: 2000
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000400014

20th century fluctuations in the abundance of siliceous microorganisms preserved in the sediments of the Puyuhuapi Channel (44° S), Chile
Provedor de dados: 97
Autores: REBOLLEDO,LORENA; LANGE,CARINA B.; FIGUEROA,DANTE; PANTOJA,SILVIO; MUÑOZ,PRÁXEDES; CASTRO,RODRIGO.
We present a 100-year reconstruction of siliceous export production from sediments of the Puyuhuapi Channel (44° S, 70° W) in the Chilean fjords. We use accumulation rates and concentrations of diatoms and silicoflagellates, organic carbon (Corg) and biogenic opal (SiOPAL) as proxies of export production, and fluctuations in the contribution of freshwater diatoms as proxies of rainfall in the hinterland and river runoff. Box core sediments collected at two sites within the Puyuhuapi Channel were analyzed: Station 35 (at the head of the fjord; 56 m water depth) and Station 40 (in the middle of the Channel; 270 m water depth). Surface sedimentation rates were 0.75 cm yr-1 at Station 35 and 0.25 cm yr-1 at Station 40. SiOPAL content averaged ~ 4 % at both...
Tipo: Journal article
Palavras-chave: Siliceous microorganisms; Diatoms; Sediments; Export production; Puyuhuapi Channel; Chilean fjords.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2005000300009

Marine diatoms from Buenos Aires coastal waters (Argentina): II. Thalassionemataceae and Rhaphoneidaceae
Provedor de dados: 97
Autores: SAR,EUGENIA A; SUNESEN,INÉS; FERNÁNDEZ,PAULA V.
This study describes the diversity of the species belonging to the diatom families Thalassionemataceae Round and Rhaphoneidaceae Forti frequently found in the temperate marine coastal waters of Buenos Aires Province, Argentina, from October 1994 to September 2000. It comprises morphological, taxonomic and distributional analysis of species found in planktonic samples collected at San Clemente del Tuyú, Santa Teresita, La Lucila del Mar, Mar de Ajó, Nueva Atlantis, Pinamar and Villa Gesell. Raw and cleaned samples were analysed with light and scanning electron microscopy. Four taxa of the genus Thalassionema Grunow ex Mereschkowsky amend. Hallegraeff, one of the genus Lioloma Hasle, two of the genus Delphineis Andrews and one of the genus Rhaphoneis...
Tipo: Journal article
Palavras-chave: Diatoms; Thalassionemataceae; Thalassionema; Lioloma; Rhaphoneidaceae; Delphineis; Rhaphoneis.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2007000100006

Diatoms from the Colombian Amazon: some species of the genus Eunotia (Bacillariophyceae)
Provedor de dados: 36
Autores: SALA,Silvia Estela; DUQUE,Santiago R.; NÚÑEZ-AVELLANEDA,Marcela; LAMARO,Anabel Alejandra.
This research was carried out in three of the most important basins of the Colombian Amazon (Upper Solimões, Iça and Japurá Rivers). The creeks and lakes that were studied contain abundant diatom species, particularly those of the genus Eunotia. Ten species are described; five of them are registered for the first time in the Amazon basin, and six in all of Colombia. All taxa were photographed with scanning electron microscopy. Fine valve morphology of E. anamargariate, E. pseudoindica, E. triodon, and E. zydodon var. compacta is described for the first time.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Eunotia; Distribution; Ecology; Colombian Amazon Basin.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672002000400589

Actinella species (Bacillariophyta) from an Amazon black water floodplain lake (Amazonas - Brazil)
Provedor de dados: 36
Autores: Melo,Sérgio; Torgan,Lezilda Carvalho; Raupp,Stela Valenti.
The genus Actinella Lewis was studied using planktonic samples from a black water floodplain lake in Central Amazon region. For species identification the taxa were morphological and morphometricaly analyzed on base in light microscope (LM) and scanning electronic microscope (SEM). Five species were registered: Actinella brasiliensis Grunow, A. guianensis Grunow, A. gracile Kociolek, A. mirabilis (Eulenstein ex Grunow) Grunow and A. robusta Hustedt. A. gracile is reported for the first time for Amazon State and black water systems and it is firstly documented with SEM. In addition, a review of geographic distribution of Actinella species in Brazilian Amazon region is given.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Actinella; Diatoms; Amazon; Black water; Floodplain lakes.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672010000200004

Coscinodiscophyceae and Fragilariophyceae (Diatomeae) in the Iguaçu River, Paraná, Brazil
Provedor de dados: 39
Autores: Nardelli,Margaret Seghetto; Bueno,Norma Catarina; Ludwig,Thelma Alvim Veiga; Tremarin,Priscila Izabel; Bartozek,Elaine Cristina Rodrigues.
A taxonomic survey was carried out on Coscinodiscophyceae and Fragilariophyceae found in the Iguaçu River catchment area within Iguaçu National Park, in the state of Paraná, Brazil. Between September 2007 and August 2008, we collected 24 samples from two stations on the Iguaçu River, upstream and downstream of the falls. We identified 37 taxa, including 22 specific and infraspecific taxa of Coscinodiscophyceae, together with 15 specific and infraspecific taxa of Fragilariophyceae. Melosira ruttneri Hustedt and Fragilaria alpestris Krasske ex Hustedt represent new records for Brazil.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Lotic systems; Southern Brazil; Taxonomy.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062014000100013

Potential effects of mechanically removing macrophytes on the phytoplankton community of a subtropical reservoir
Provedor de dados: 39
Autores: Wojciechowski,Juliana; Burda,Tamires Marcela; Scheer,Mauricio Bergamini; Costa,Elaine Aparecida Dias da; Fernandes,Luciano Felício.
ABSTRACT Intensive growth of aquatic macrophytes interferes with water quality and ecosystem dynamics worldwide. Although mechanically removing macrophytes is the most commonly used method for their eradication, it can also cause undesirable disturbances in aquatic reservoir communities. We performed laboratory incubations of phytoplankton sampled before and after macrophytes were mechanically removed from the Piraquara II reservoir, South Brazil. We analyzed changes in growth and composition of the main phytoplankton groups with respect to nutrient shifting. Prior to removing the macrophytes, the phytoplankton community was dominated by low cell abundances of diatoms and flagellates. In contrast, growth rates of cyanobacteria (mainly Cylindrospermopsis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophytes; Cyanobacteria; Diatoms; Macrophytes; Mechanical removal; Phytoplankton; Reservoir management.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062018000400588

The phytoplankton of Guanabara Bay, Brazil: I. historical account of its biodiversity
Provedor de dados: 49
Autores: Villac,Maria Célia; Tenenbaum,Denise Rivera.
This is a historical account of the biodiversity of phytoplankton in Guanabara Bay, Brazil. It is based on 57 publications that refer to sampling carried out between 1913 and 2004. The publications included are those with direct microscopic identification. Although 80% of the studies focus on ecological issues that tend to mention only the most abundant species, 24 publications provide comprehensive check-lists at the species level, especially of taxa &gt; 20 μm. The inventory of species includes, to date, 308 taxa among 199 diatoms, 90 dinoflagellates, 9 cyanobacteria, 5 euglenophyceans, 1 chlorophycean, 1 prasinophycean, 1 silicoflagellate, and 2 ebriids. The most conspicuous species were the dinoflagellate Scrippsiella trochoidea and diatoms from the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Marine microalgae; Diatoms; Dinoflagellates; Cyanobacteria; Algal blooms.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032010000200030

The genus Tryblionella W. Smith (Bacillariaceae, Bacillariophyta) in southern Brazil salt marshes
Provedor de dados: 49
Autores: Bertolli,Lucielle Merlym; Talgatti,Dávia Marciana; Nascimento,Thamires Mariah da Silveira; Torgan,Lezilda Carvalho.
Abstract: Tryblionella is a large epipelic genus, widespread from fresh to marine waters. Most of the studies including the genus are based only in light microscopy. Few recent studies are exclusively dedicated to Tryblionella and the ultrastructure of some species is still little known. In this paper we present eleven species of Tryblionella found in epiphyton and microphytobenthos in Patos Lagoon salt marshes. All the species are described, illustrated in light and scanning electron microscopy and comments about their taxonomy, distribution and ecology are provided. Two taxa are reported for the first time in the State of Rio Grande do Sul and one in Southern Brazil. The number of species registered in this study comprises nearly a half of the number of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Patos Lagoon; Periphyton; Taxonomy; Ultrastructure.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032020000100204

Melosira (Diatomeae) taxa from the Iguaçu River in southern Brazil
Provedor de dados: 49
Autores: Nardelli,Margaret Seghetto; Tremarin,Priscila Izabel; Ludwig,Thelma Alvim Veiga; Bueno,Norma Catarina.
Abstract The study of the genus Melosira in plankton samples from the lower Iguaçu River revealed the presence of four taxa: Melosira undulata (Ehrenberg) Kützing var. undulata, M. undulata var. normanni Arnott, M. varians C. Agardh and M. muscigena Iwahashi. We present illustrations of the frustules using light microscopy (LM), descriptions, and comments about the morphology of the four taxa. The analysis of Melosira muscigena under scanning electron microscopy revealed unprecedented details of the ultrastructure, such as the shape and distribution of the rimoportulae at the valve mantle. This is the first record of Melosira undulata var. undulata and the second of M. muscigena in Brazil.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Southern Brazil; Taxonomy; Ultrastructure.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000400202

The phytoplankton biodiversity of the coast of the state of São Paulo, Brazil
Provedor de dados: 49
Autores: Villac,Maria Célia; Cabral-Noronha,Valéria Aparecida de Paula; Pinto,Thatiana de Oliveira.
The objective of this study is to compile the inventory of nearly 100 years of research about the phytoplankton species cited for the coast of the state of São Paulo, Brazil. A state-of-the-art study on the local biodiversity has long been needed to provide a baseline for future comparisons. This type of data is scattered in old scientific journals and in the so-called "grey literature", and are in need of nomenclature updating. Twenty-six publications are considered. The earliest sampling record is from 1913 (?) and the most recent from 2002. This checklist compiled from the literature was complemented with primary data collected between August 2004 and July 2006, recent surveys of the surf-zone of 20 beaches located along the coast and of a mariculture...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Marine microalgae; Inventory; Diatoms; Dinoflagellates.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032008000300015

Periphytic algae in a floodplain lake and river under low water conditions
Provedor de dados: 49
Autores: Bichoff,Andressa; Osório,Nicolli Cristina; Dunck,Bárbara; Rodrigues,Liliana.
Abstract Drought events will become more frequent due the climate change. In floodplains, periphytic algae are responsible for part of the primary production, are the principal source of organic carbon deposition, play an important role in mineralization and nutrient cycling, and are the base of the food web for many organisms. As algae distribution in aquatic environments is a strong indicator of physical and chemical conditions of the sites, we aimed to determine the structure of periphytic algae in lentic and lotic environments during drought conditions and to uncover the main local abiotic factors in community structuring. We hypothesized diatoms would be more frequent than green algae and desmids at both sites, due to their resistance characteristics,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Flood pulse; Freshwater; Drought events.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000300201

Gomphonema Ehrenberg (Bacillariophyceae, Gomphonemataceae) of the São Francisco Falso River, Paraná, Brazil
Provedor de dados: 49
Autores: Medeiros,Gabriela; Amaral,Mailor Wellinton Wedig; Ferreira,Paula Carolina; Ludwig,Thelma Veiga; Bueno,Norma Catarina.
Abstract: Gomphonema Ehrenberg is a genus well represented in periphytic algal flora of epicontinental environments. The substrate colonization is facilitated by the secretion of mucilage by the pore field, allowing cell adhesion. Samples were scraped off and analyzed from vegetative portions of the macrophyte Eichhornia azurea Kunth, collected in São Francisco Falso River, located in Santa Helena City, Paraná State. The sampling occurred in four different sites, in four different periods, totaling 16 samples. The quantitative material analysis resulted in 28 identified taxa, in which Gomphonema brasiliense ssp. pacificum, Gomphonema neoapiculatum Lange-Bertalot, Reichardt &amp; Metzeltin Gomphonema pantropicum Reichardt and Gomphonema perapicatum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lotic environment; Diatoms; Taxonomy; Ultrastructure.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032018000300205

First record of Thalassiosira Catharinensis (Bacillariophyta) from Argentinean marine coastal waters
Provedor de dados: 51
Autores: LAVIGNE,ANDREA S.; SUNESEN,INÉS; SAR,EUGENIA A.
Several ultrastructural analyses of taxa belonging to the genus Thalassiosira from Argentinean coastal waters were carried out, nevertheless, the smaller fraction of the nanoplanktonic Thalassiosira was frequently overlooked. The aim of this study is to show the morphological variation of T . catharinensis, to compare material found in marine coastal waters of Anegada Bay, Province of Buenos Aires, with the material analyzed in the protologue and allied taxa, and to record the species for the frst time in Argentina, extending its distribution.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anegada Bay; Argentina; Diatoms; Frst record; Marine coastal waters; Thalassiosira catharinensis.
Ano: 2018
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-23722018000200005

Valve morphology of Didymosphenia geminata (Bacillariophyceae) in Chubut province, Argentina
Provedor de dados: 51
Autores: Uyua,Noelia Mariel; Santinelli,Norma Herminia; Sastre,Alicia Viviana; Sala,Silvia Estela.
Didymosphenia was recently found in Patagonia forming massive proliferations. In Argentina the species scattered in a short time to five provinces. Here, we analyse morphologic and morphometric data of specimens collected at Chubut Province, Argentina, and we compare them with other species of this genus reported from different regions of the world. Materials were collected in two basins during 2010- 2012. Samples analyzed with LM and SEM showed inter and intrapopulation variation in morphometric characteristics and in some valve structures such as spines. The studied material corresponds in valve outline and morphology to D. geminata ssp geminata Metzeltin &amp;amp; Lange-Bertalot. Our materials also resemble a group of species: D. clavaherculis, D....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Didymo; Patagonia; Morphometry; Nuisance species.
Ano: 2016
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-23722016000100002

Diatom assemblage in a tropical lake of northeastern Brazil
Provedor de dados: 52
Autores: Nascimento,Lilian Rodrigues do; Sifeddine,Abdelfettah; Torgan,Lezilda Carvalho; Albuquerque,Ana Luiza Spadano.
The composition and spatial variation of diatom assemblage in surface sediments of Caçó Lake (shallow, mesotrophic and weakly acid lake - Maranhão State, Brazil) were analyzed in order to know the distribution pattern of the species along the lake during rainy season (April 1999). Four zones were established in the lake based on 21 diatoms species and habitat affinities. The first three zones (prime three meters deep to six meters deep) were marked by the occurrence of Pinnularia gigas, Frustulia rhomboides, Encyonopsis krasskei, Eunotia camelus, E. femoriformis and E. monodon. Zone IV (seven to nine meters deep) was inhabited mainly by Surirella biseriata and Fragilariforma floridana. During the beginning of the rainy season, the diatom assemblage in Caçó...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diatoms; Shallow lake; Surface sediments; Caçó Lake; Brazil.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000100030

Effect of cobalt on growth, pigments and the photosynthetic electron transport in Monoraphidium minutum and Nitzchia perminuta
Provedor de dados: 61
Autores: El-Sheekh,M.M.; El-Naggar,A.H.; Osman,M.E.H.; El-Mazaly,E.
The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured under different concentrations of Co2+. Growth and pigment content were slightly increased at low concentrations and inhibited by high Co2+ concentrations. The results concerning the effect of different concentrations of Co2+ on photosynthetic O2 evolution showed a reduction in the amount of O2 evolved by each alga in response to increasing Co2+ concentrations. However, an increase in O2 evolution for both M. minutum and N. perminuta was observed at relatively low Co2+ concentrations. Photosynthetic electron transport in M. minutum was more sensitive to Co2+ toxicity than in N. perminuta. On the other hand, the effect of the heavy metal on respiration showed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cobalt; Diatoms; Green algae; Pigments; Photosynthesis.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300005