Consulta: subjectFacets:"Oligotrophy"
Registros recuperados: 7
Data/hora: 15/06/2024 16:54:00

Short-scale temporal variability of physical, biological and biogeochemical processes in the NW Mediterranean Sea: an introduction
Provedor de dados: 5
Autores: Andersen, V.; Goutx, M.; Prieur, L.; Dolan, J. R.
In the framework of the PROOF-PECHE project (http://www.obs-vlfr.fr/proof/vt/op/ec/peche/pec.htm) a multi-disciplinary team performed experiments and collected samples during the DYNAPROC2 cruise aboard the RV Thalassa from September to October in 2004. The cruise provided data on the functioning of the pelagic food web by sampling over a month long period in the NW Mediterranean Sea at a fixed station subject to weak horizontal advection currents during a period of hydrological stability. This paper describes the background of the cruise and provides an overview of the results derived from the campaign which constitute the special section. The major objective of the cruise was to assess the relative importance and variability of the pathways of carbon in...
Tipo: Text
Palavras-chave: Spring bloom; Zooplankton community; Vertical distribution; Surface layer; Wind events; Bacterial communities; Food web; Transition; Oligotrophy; Abundance.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/00092/20315/17954.pdf

Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime
Provedor de dados: 5
Autores: Levy, Marina; Klein, Patrice; Treguier, Anne-marie.
Using a protocol of numerical experiments where horizontal resolution is progressively increased, we show that small-scale (or sub-mesoscale) physics has a strong impact on both mesoscale physics and phytoplankton production/subduction.Mesoscale and sub-mesoscale physics result from the nonlinear equilibration of an unstable baroclinic jet. The biogeochemical context is oligotrophy. The explicitly resolved sub-mesoscales, at least smaller than one fifth of the internal Rossby radius of deformation, reinforce the mesoscale eddy field and contribute to double the primary production and phytoplankton subduction budgets. This enhancement is due to the reinforced mesoscale physics and is also achieved by the small-scale frontal dynamics. This sub-mesoscale...
Tipo: Text
Palavras-chave: Oligotrophy; Phytoplankton production; Vorticity gradient; Eddy field; Mesoscale physics.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-800.pdf

Feeding strategies and resource partitioning mitigate the effects of oligotrophy for marine cave mysids
Provedor de dados: 5
Autores: Rastorgueff, Pierre-alexandre; Harmelin-vivien, Mireille; Richard, Pierre; Chevaldonne, Pierre.
We investigated how large populations of several mysid species can coexist in oligo trophic underwater marine caves and their relationships in the marine cave food web using carbon and nitrogen stable isotopes. Isotopic signatures indicate food partitioning among the 5 species of cave-dwelling mysids from the northwest Mediterranean Sea we studied. Hemimysis speluncola feeds mainly on phytoplankton and zooplankton from outside the caves, Siriella gracilipes on sedimentary organic matter and zooplankton from outside, Harmelinella mariannae on small cave-dwelling crustaceans, and Hemimysis margalefi and Hemimysis lamornae mediterranea on sedimentary particulate organic matter. These differences in diet could promote coexistence of such diverse and abundant...
Tipo: Text
Palavras-chave: Trophic ecology; Resource partitioning; Mysidacea; Marine caves; Oligotrophy; Stable isotopes; NW Mediterranean.
Ano: 2011
URL: https://archimer.ifremer.fr/doc/00372/48307/48426.pdf

Archaea in organic-lean and organic-rich marine subsurface sediments: an environmental gradient reflected in distinct phylogenetic lineages
Provedor de dados: 5
Autores: Durbin, Alan M.; Teske, Andreas.
Examining the patterns of archaeal diversity in little-explored organic-lean marine subsurface sediments presents an opportunity to study the association of phylogenetic affiliation and habitat preference in uncultured marine Archaea. Here we have compiled and re-analyzed published archaeal 16S rRNA clone library datasets across a spectrum of sediment trophic states characterized by a wide range of terminal electron-accepting processes. Our results show that organic-lean marine sediments in deep marine basins and oligotrophic open ocean locations are inhabited by distinct lineages of archaea that are not found in the more frequently studied, organic-rich continental margin sediments. We hypothesize that different combinations of electron donor and acceptor...
Tipo: Text
Palavras-chave: Archaea; Marine sediments; Oligotrophy; Subsurface; Phylogeny; Uncultured archaea.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00263/37444/35695.pdf

Feeding strategies of co-occurring suspension feeders in an oligotrophic environment
Provedor de dados: 5
Autores: Cresson, Pierre; Ruitton, Sandrine; Harmelin-vivien, Mireille.
Suspension-feeders predominate in the vast majority of the coastal marine benthic ecosystems, with several species co-occurring at low spatial scale. Understanding how these species cope with competition for trophic resources has been the core of numerous studies, mostly in coastal shallow systems where food supplies are diverse and abundant. Oligotrophic systems have received less attention. The aim of the present study was thus to investigate the trophic relationships established between 9 suspension feeders collected in an oligotrophic zone (Bay of Marseille, French Mediterranean). Species displayed similar isotopic ratios, consistently with the use of one main source, identified as nanophytoplankton and diazotrophic bacteria as the δ15N values were...
Tipo: Text
Palavras-chave: Suspension feeders; Isotopic niche; Mediterranean; Oligotrophy; Resource sharing mechanisms.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00301/41203/40363.pdf

Species assemblages of zooplanktonic crustaceans in mountain shallow ponds of Chile (Parque Cañi)
Provedor de dados: 103
Autores: Ríos,Patricio De los; Roa,Guido.
Even though the Chilean lakes are characterized by their oligotrophy, a transition from oligotrophy to mesotrophy, due human intervention, has been reported in some lakes. Nevertheless, there are still some pristine and unpolluted small lakes and ponds in mountain zones, free of human intervention and surrounded by native forests. Nine unpolluted, oligotrophic and pristine water bodies located in Cañi Park, a mountain zone with altitudes between 1000 to 1500 m a.s.l and forests where Nothofagus dombeyi, N. pumilio and Araucaria araucana predominate, were studied. For each sampled lake, zooplankton was collected and environmental parameters were obtained (conductivity, total dissolved solids, and chlorophyll concentration). A null model of species...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Boeckella gracilis; Null model; Oligotrophy; Zooplankton.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000100012

Oligotrophic patterns in southern Chilean lakes: the relevance of nutrients and mixing depth
Provedor de dados: 97
Autores: SOTO,DORIS.
Southern Chilean monomictic, temperate lakes are generally oligotrophic with high water transparency, low productivity and some apparent resistance to disturbances such as phosphorus additions. This paper attempts to explain low chlorophyll-a values using descriptive and experimental approaches. Three different scales are used, (a) a micro scale both in space and time, with experimental manipulations of N, P and total light in 24 enclosures in lake Llanquihue, (b) a longer time scale analysing 18 months of data in several sites within lake Llanquihue grouped as salmon farming sites, town bays and control sites, and (c) a broader time scale (9 years) by monitoring lakes Puyehue, Rupanco and Llanquihue, all in the Araucanian lake region and Yelcho lake in...
Tipo: Journal article
Palavras-chave: Oligotrophy; Mixing depth; Nitrogen; Temperate lakes.
Ano: 2002
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2002000200009