Consulta: subjectFacets:"Microbial food web"
Registros recuperados: 7
Data/hora: 01/06/2024 10:48:58

Eutrophication disrupts summer trophic links in an estuarine microbial food web
Provedor de dados: 5
Autores: López-abbate, M.c.; Molinero, Juan-carlos; Barría De Cao, M.s.; Silva, R.; Negri, R.; Guinder, V.a.; Hozbor, M.c.; Hoffmeyer, M.s.
Eutrophication is the most widespread effect of urban development in coastal areas. To elucidate how nutrient loading affects the carbon pathways at the base of food chains, we quantified the carbon transfer among microbial components, from prokaryotes to microzooplankton. For this purpose, we performed two size-fractionation feeding experiments during late summer under moderate (N: 28.5 μM, P: 0.92 μM, Si: 45.8 μM) and severe (N: 173.9 μM, P: 3.5 μM, Si: 67.2 μM) cultural eutrophication in the Bahía Blanca Estuary (Argentina). In both experiments, prokaryotes were largely dominated by heterotrophic forms, small diatoms dominated among autotrophs, and heterotrophic nanoflagellates were the most abundant among protistan grazers. Under severe eutrophication,...
Tipo: Text
Palavras-chave: Eutrophication; Microbial food web; Bacteria; Nanoflagellates; Microzooplankton; Estuaries.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00512/62335/66718.pdf

How trophic cascades and photic zone nutrient content interact to generate basin-scale differences in the microbial food web
Provedor de dados: 5
Autores: Thingstad, T Frede; Browman, Howard.
In linear food chains, resource and predator control produce positive and negative correlations, respectively, between biomass at adjacent trophic levels. These simple relationships become more complex in food webs that contain alternative food chains of unequal lengths. We have used a “minimum” model for the microbial part of the pelagic food web that has three such food chains connecting free mineral nutrients to copepods: via diatoms, autotrophic flagellates, and heterotrophic bacteria. Trophic cascades from copepods strongly modulates the balance between the three pathways and, therefore, the functionality of the microbial food web in services such as food production for higher trophic levels, DOM degradation, and ocean carbon sequestration. The result...
Tipo: Text
Palavras-chave: Arctic Ocean; Bottom-up; Mediterranean Sea; Microbial food web; Nansen Legacy; Top down; Trophic cascades.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00627/73958/73312.pdf

Feeding rate of the oyster Crassostrea gigas in a natural planktonic community of the Mediterranean Thau Lagoon
Provedor de dados: 5
Autores: Dupuy, Christine; Vaquer, André; Lam Hoai, Thong; Rougier, Claude; Mazouni, Nabila; Lautier, Jacques; Collos, Yves; Le Gall, Solange.
The Mediterranean Thau Lagoon is an important oyster farming area in Europe. Oyster growth rates are among the highest in France, although chlorophyll a concentration is low. Previous studies have demonstrated that picophytoplankton, nano-microphytoplankton, dinoflagellates and loricate ciliates such as tintinnids are abundant. However, heterotrophic flagellates and aloricate ciliates have not been investigated. The aim of this study was to assess picophytoplankton, protist and zooplankton abundances in the Lagoon and to investigate the particular structure of the microbial food web, which may explain such paradoxical oyster growth. In oligotrophic waters in the Thau Lagoon, the picoeukaryote Ostreococcus tauri is the dominant autotrophic picoplankter,...
Tipo: Text
Palavras-chave: Trophic link; Picophytoplankton; Heterotrophic protist; Microbial food web; Thau Lagoon; Food source; Oyster; Bivalve.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-812.pdf

Marine Microbial Food Web Networks During Phytoplankton Bloom and Non-bloom Periods: Warming Favors Smaller Organism Interactions and Intensifies Trophic Cascade
Provedor de dados: 5
Autores: Trombetta, Thomas; Vidussi, Francesca; Roques, Cecile; Scotti, Marco; Mostajir, Behzad.
Microbial food web organisms are at the base of the functioning of pelagic ecosystems and support the whole marine food web. They are very reactive to environmental changes and their interactions are modified in response to different productive periods such as phytoplankton bloom and non-bloom as well as contrasted climatic years. To study ecological associations, identify potential interactions between microorganisms and study the structure of the microbial food web in coastal waters, a weekly monitoring was carried out in the Thau Lagoon on the French Mediterranean coast. The monitoring lasted from winter to late spring during two contrasting climatic years, a typical Mediterranean (2015) and a year with an extreme warm winter (2016). Correlation...
Tipo: Text
Palavras-chave: Microorganism interactions; Correlation networks; Phytoplankton bloom; Warming; Microbial food web; Shallow coastal zone.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00659/77102/78437.pdf

Microbial food web structural and functional responses to oyster and fish as top predators
Provedor de dados: 5
Autores: Mostajir, Behzad; Roques, Cecile; Bouvier, Corinne; Bouvier, Thierry; Fouilland, Eric; Got, Patrice; Le Floc'H, Emilie; Nouguier, Jean; Mas, Sebastien; Sempere, Richard; Sime-ngando, Telesphore; Troussellier, Marc; Vidussi, Francesca.
The impact of fish and oysters on components of the pelagic microbial food web (MFW) was studied in a 10 d mesocosm experiment using Mediterranean coastal waters. Two mesocosms contained natural water only ('Controls'), 2 contained natural water with Crassostrea gigas ('Oyster'), and 2 contained natural water with Atherina spp. ('Fish'). Abundances and biomasses of microorganisms (viruses, bacteria, phytoplankton, heterotrophic flagellates, and ciliates) were measured to estimate their contribution to the total microbial carbon biomass. Two MFW indices, the microbial autotroph: heterotroph C biomass ratio (A:H) structural index and the gross primary production: respiration ratio (GPP:R) functional index, were defined. In the Fish mesocosms, selective...
Tipo: Text
Palavras-chave: Microbial food web; Virioplankton; Bacterioplankton; Phytoplankton; Protozooplankton; Crassostrea; Atherina; Autotrophy; Heterotrophy.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00284/39489/73675.pdf

Impact of the oyster Crassostrea gigas on a microbial community in Atlantic coastal ponds near La Rochelle
Provedor de dados: 5
Autores: Dupuy, Christine; Pastoureaud, Annie; Ryckaert, Mireille; Sauriau, Pierre-guy; Montanie, Hélène.
To assess the in situ impact of oysters Crassostrea gigas on planktonic protist and bacteria communities and the potential contribution of protozoa to their food resource intake, the abundance and the diversity of protists and bacteria were followed in 2 Atlantic coastal ponds, with and without oysters. The protist biomass in such ponds was high, with a maximum in spring of 982 mug C l(-1) and a minimum in winter of 179 pg C l(-1). Whatever the season, the presence of oysters (20 m(-2) corresponding to an average of 23 mg dry weight m(-2)) induced a significant decrease in &gt;5 pm protist abundance. On the contrary, planktonic organisms &lt;5 pm, such as Chlorophyta flagellates and bacteria, developed similarly in both ponds. It can be assumed that such...
Tipo: Text
Palavras-chave: Trophic link; Bacteria; Protists; Microbial food web; Coastal pond; Food source; Oysters; Bivalve.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-822.pdf

Protozoans bacterivory in a subtropical environment during a dry/cold and a rainy/warm season
Provedor de dados: 58
Autores: Hisatugo,Karina F.; Mansano,Adrislaine S.; Seleghim,Mirna H.R.
In aquatic ecosystems, bacteria are controlled by several organisms in the food chain, such as protozoa, that use them as food source. This study aimed to quantify the ingestion and clearance rates of bacteria by ciliates and heterotrophic nanoflagellates (HNF) in a subtropical freshwater reservoir (Monjolinho reservoir -São Carlos -Brazil) during one year period, in order to verify their importance as consumers and controllers of bacteria in two seasons, a dry/cold and a rainy/warm one. For this purpose, in situ bacterivory experiments were carried out bimonthly using fluorescently labeled bacteria with 5-(4,6 diclorotriazin-2yl) aminofluorescein (DTAF). Although ciliates have shown the highest individual ingestion and clearance rates, bacterivory was...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Bacteria; Grazing; Ciliates; Nanoflagellates; Microbial food web.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000100020