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| Registros recuperados: 20 | |
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| Lazure, Pascal; Jegou, Anne-marie; Kerdreux, Michel. |
| The Bay of Biscay is characterised by large fresh water inputs from two major rivers, the Loire and the Gironde, with a mean discharge of about 900 m(3)/s. To describe the spatial and temporal variability of the Loire and Gironde plumes, continuous salinity measurements were made at 4 locations on French coastal islands over periods lasting at least two years. These islands are located at a distance from the large local gradients linked to local inputs. Whereas sea surface salinity in the centre of the Bay of Biscay is 35.6, salinities at the coast vary between about 35 in summer to occasionally less than 30 in late winter or in spring. Minimum salinities do not occur at the same time along the coast, indicating a strong spatial gradient. Near the Loire... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Continental shelf; River plume; Seasonal variability; Salinity; Hydrology. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3957.pdf |
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| Silva,Marcelo H. L.; Torres Júnior,Audálio R.; Castro,Antonio C. L.; Azevedo,James W. J.; Ferreira,Cássia F. C.; Cardoso,Rayssa L.; Nunes,Jorge L. S.; Carvalho-Neta,Raimunda N. F.. |
| ABSTRACT: The fish assemblage structure in a port area in São Marcos Bay (Amazonic coast) was evaluated based on the spatial and temporal distributions to identify potential changes in response to anthropic pressure increases associated with industrial and port activities in region. The samples were taken between March 2011 and November 2015. The ichthyofauna was represented by a total of 56 species, distributed in 15 orders and 29 families. Captures were dominated by Genyatremus luteus (Bloch, 1790), but Sciades proops (Valenciennes, 1840) was the most representative in terms of biomass. Seasonal distributions of fish assemblage did not reveal significant differences. However, there was a difference between catch sites, abundance, biomass and Shannon... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ichthyofauna; Estuary; Seasonal variability; Spatial patterns; Maranhão Amazon. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212018000100218 |
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| Mérona,Bernard de; Rankin-de-Mérona,Judy. |
| Diets of most of fish species inhabiting a floodplain lake in central Amazonia were studied over a two years and half period. Based on the percentage of relative occurrence of 11 major food categories a classification of species in 11 feeding guilds is proposed. Many species were found to be specialized feeders. Fish, detritus and insects were the most important food resources supporting the fish community in both seasons, but the proportions of fruits, invertebrates and fish were reduced during the low water season. At the community level mean diet overlap between species was low, suggesting efficient resource partitioning within the community. However mean overlap between unspecialized feeders was high. Based on the 23 most abundant species belonging to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Varzea lake; Fishes; Diet; Overlap; Seasonal variability. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252004000200004 |
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| Puillat, Ingrid; Lazure, Pascal; Jegou, Anne-marie; Lampert, Luis; Miller, P. |
| A synthesis of 9 years of hydrographic measurements, acquired during approximately 25 cruises (1992-2000) on the French continental shelf of the Bay of Biscay, is presented. The main focus is upon salinity distribution, as it is little known in this area. The whole of the data set covers I I months of the year, with some sampling fields repeated several times a year, for multiple years. This time-series allows temperature and salinity distributions to be studied together with their seasonal, inter-annual and mesoscale variability. The seasonal trend in temperature can be described in three stages, which are in agreement with past studies. Thermal stratification occurs between May and mid-September in a layer similar to 50 m in thickness, whereas the... |
| Tipo: Text |
Palavras-chave: Upwelling; Cold pool; River plumes; Seasonal variability; Salinity; Hydrography. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-779.pdf |
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| Poulard, Jean-charles; Leaute, Jean-pierre. |
| Marine populations are distributed heterogeneously in space and time because of the diversity of habitats and the requirements of species life cycles. Human exploitation of these resources also varies as a function of space, time and the type of fishing activities performed. These three factors determine fishing strategy at different levels of integration. The purpose of this study was to describe and analyse, with respect to different time scales, the relations between the modalities of resource exploitation and the biological or demographic characteristics of the species involved. These investigations relate to the more general task of acquiring the basic knowledge needed for spatialised management of fishing effort. A fleet of trawlers from La Rochelle,... |
| Tipo: Text |
Palavras-chave: Atlantic ocean; Bay of Biscay; Seasonal variability; Multiple factor analysis; Bottom trawlers; Landings. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-1397.pdf |
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| Thierry, Virginie; Treguier, Anne-marie; Mercier, Herle. |
| Using idealized and realistic high-resolution primitive equation models, we explore the annual and semi-annual period fluctuations in the deep equatorial Atlantic Ocean. The deep seasonal variability derives its energy from the equatorial zonal wind stress component and the wind energy reaches the deep layers by means of vertically propagating Kelvin and Rossby waves. The first meridional mode (l = 1) annual Rossby wave reaches the western boundary while the other Rossby waves directly propagate toward the bottom. A deep Kelvin wave is generated by the reflection of the incoming l = 1 annual Rossby wave at the western boundary. Due to the complexity of the surface layers in the non-linear simulations, one cannot separate the waves generated at the... |
| Tipo: Text |
Palavras-chave: Wind driven circulation; Seasonal variability; Equatorial waves. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-670.pdf |
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| Keppler, L.; Landschützer, P.; Gruber, N.; Lauvset, S. K.; Stemmler, I.. |
| The seasonal cycle represents one of the largest signals of dissolved inorganic carbon (DIC) in the ocean, yet these seasonal variations are not well established at a global scale. Here, we present the Mapped Observation‐Based Oceanic DIC (MOBO‐DIC) product, a monthly DIC climatology developed based on the DIC measurements from GLODAPv2.2019 and a two‐step neural network method to interpolate and map the measurements. MOBO‐DIC extends from the surface down to 2,000 m and from 65°N to 65°S. We find the largest seasonal amplitudes of surface DIC in the northern high‐latitude Pacific (∼30 to >50 μmol kg−1). Surface DIC maxima occur in hemispheric spring and minima in fall, driven by the input of DIC into the upper ocean by mixing during winter, and net... |
| Tipo: Text |
Palavras-chave: DIC; Seasonal variability; Neural networks; SOM‐ FFN; Monthly climatology; NCP. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00668/78016/80262.pdf |
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| Qiu, Bo; Chen, Shuiming; Klein, Patrice; Sasaki, Hideharu; Sasai, Yoshikazu. |
| Located at the center of the western North Pacific Subtropical Gyre, the Subtropical Countercurrent (STCC) is not only abundant in mesoscale eddies, but also exhibits prominent submesoscale eddy features. Output from a 1/30 degrees high-resolution OGCM simulation and a gridded satellite altimetry product are analyzed to contrast the seasonal STCC variability in the mesoscale versus submesoscale ranges. Resolving the eddy scales of >150 km, the altimetry product reveals that the STCC eddy kinetic energy and rms vorticity have a seasonal maximum in May and April, respectively, a weak positive vorticity skewness without seasonal dependence, and an inverse (forward) kinetic energy cascade for wavelengths larger (shorter) than 250 km. In contrast, the... |
| Tipo: Text |
Palavras-chave: Circulation/ Dynamics; Eddies; Instability; Mesoscale processes; Observational techniques and algorithms; Altimetry; Models and modeling; Ocean models; Variability; Seasonal variability. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00245/35588/34142.pdf |
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| Colling,Leonir A.; Bemvenuti,Carlos E.; Gandra,Michel S.. |
| The aim of this study is to analyze and relate the spatial-temporal variability of macrozoobenthic assemblages to bottom characteristics and salinity fluctuations, in an estuarine shallow water region of Patos Lagoon. Monthly samples, between September 2002 and August 2003, were taken on six sampling stations (distant 90 m). Three biological samples with a 10 cm diameter corer, one sample for sediment analysis, fortnightly bottom topography measurements, and daily data of temperature and salinity were taken from each station. Two biotic and environmental conditions were identified: the first corresponding to spring and summer months, with low macrozoobenthos densities, low values of salinity, small variations in bottom topographic level and weak... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Seasonal variability; Benthos; Estuary; Abiotic variables; Sublittoral habitats. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212007000300007 |
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| Gurdek,Rodrigo; Acuña-Plavan,Alicia. |
| ABSTRACT Estuaries are highly dynamic ecosystems subjected to variability of their fish communities over different time scales. The nearshore fish community of the lower Pando estuary, a temperate sub-system of the Río de la Plata estuary, was sampled from May 2002 to June 2003. A total of 2,165 fishes, represented by 16 species were caught by seine netting. Captures were dominated by juveniles (>90%), as well as by the sciaenid Micropogonias furnieri (Desmarest, 1823) (82.8%). The fish community showed high seasonal variability, with the greatest diversity and biomass in summer and spring and the highest species richness during summer. Lowest values of all community parameters occurred in winter and autumn, seasons that presented the highest similarity... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ichthyofauna; Community parameters; Seasonal variability; Diel variability; Sub-estuary. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212017000100203 |
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| Pott,Cristiano A.; Jadoski,Sidnei O.; Schmalz,Britta; Hörmann,Georg; Fohrer,Nicola. |
| Daily time series were used to verify the temporal variability and to characterize the nitrogen (N) and phosphorus (P) pollution in a 462 km² catchment of the Stör river, a typical rural lowland catchment in Germany. Also, this study aimed to identify the best sampling frequency of pollution by N and P. Total phosphorus (TP), soluble orthophosphate-phosphorus (PO4-P), particulate-phosphorus (PP), total nitrogen (TN), nitrate-nitrogen (NO3-N) ammonium-nitrogen (NH4-N) and total suspended sediment (TSS) were analysed. Daily monitoring from August 8, 2009 until August 10, 2011 was conducted with an automatic water sampler at the outlet of the catchment. The results show a seasonal variability of water quality parameters with more N and P concentration in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water quality; Nitrate; Phosphate; Autocorrelation; Automatic water sampler; Seasonal variability. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662014000800005 |
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| 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 |
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| Стельмах, Л. В.; Бабич, И. И.; Ляшенко, С. В.. |
| На основе данных, полученных на трех станциях в прибрежных водах Черного моря в районе Севастополя в 2000 – 2001 гг , представлена сезонная динамика концентрации хлорофилла “a” в планктоне и отношения С/Хл”a” в микро- и наннофитопланктоне поверхностных вод. В течение года эти показатели изменялись более, чем на порядок. Так, концентрация хлорофилла “а” изменялась от 0,21 до 14,28 мг. м-3 и достигала максимальных значений в весенний и осенний периоды, что обусловлено “цветением” диатомовых водорослей Chaetoceros socialis весной и Cerataulina bergonii осенью. Максимальные значения отношения С/Хл”a” (158 - 183 ) были получены в летний период (в июле), когда в фитопланктоне доминировали пирофитовые водоросли, минимальные значения (13 –20)... |
| Tipo: Journal Contribution |
Palavras-chave: Фитопланктон; Хлорофилл "a"; Диатомовые водоросли; Пирофитовые водоросли; Chlorophyll “a”; Seasonal variability; Phytoplankton; Pyrrophyta Seasonal variations Phytoplankton Chlorophylls Diatoms Phytoplankton Chlorophylls Diatoms http://aims.fao.org/aos/agrovoc/c_13344 http://aims.fao.org/aos/agrovoc/c_1577 http://aims.fao.org/aos/agrovoc/c_32657. |
| Ano: 2002 |
URL: http://repository.ibss.org.ua/dspace/handle/99011/411 |
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| Registros recuperados: 20 | |
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