Browsing NTNU Open by Author "Sanchez, Nicolas"
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Distribution and Variation of the Trace Metal Iron in the Base of the Pelagic Marine Food Web: A Mesocosm Approach: Trace Metal in marine biology
Sanchez, Nicolas (Master thesis, 2012)This study was part of the WAFOW project “Can waste emission from fish farms change the structure of marine food webs?” whose objective was to perform mesocosms experiment to simulate the ammonium enriched environment, ... -
Effect of hydroxamate and catecholate siderophores on iron availability in the diatom Skeletonema costatum: Implications of siderophore degradation by associated bacteria
Sanchez, Nicolas; Peterson, Claire Katja; Villa Gonzalez, Susana; Vadstein, Olav; Olsen, Yngvar; Ardelan, Murat Van (Journal article; Peer reviewed, 2019)The bioavailability of iron (Fe) across marine ecosystems, mainly determined by Fe speciation and species-specific requirements of phytoplankton, remains largely unresolved. Siderophores are relevant within the pool of ... -
Effect of Siderophore on Iron Availability in a Diatom and a Dinoflagellate Species: Contrasting Response in Associated Bacteria
Sanchez, Nicolas; Brown, Eunice Nana Adjoa; Olsen, Yngvar; Vadstein, Olav; Iriarte, Jose Luis; Gonzalez, Humberto E.; Ardelan, Murat Van (Journal article; Peer reviewed, 2018)Organic ligands play a key role controlling trace metal bioavailability in the world's oceans, yet the species-specific requirements determining whether certain iron forms can be metabolized largely remain unclear. ... -
Experiment design and bacterial abundance control extracellular H2O2 concentrations during four series of mesocosm experiments
Hopwood, M. J.; Sanchez, Nicolas; Polyviou, Despo; Leiknes, Øystein; Gallego-Urrea, Julian Alberto; Achterberg, Eric P.; Ardelan, Murat Van; Aristegui, Javier; Bach, Lennart T.; Besiktepe, Sengul; Heriot, Yohann; Kalantzi, Ioanna; Terblylk Kurt, Tuba; Santi, Ioulia; Tsagaraki, Tatiana Margo; Turner, David (Peer reviewed; Journal article, 2020)The extracellular concentration of H2O2 in surface aquatic environments is controlled by a balance between photochemical production and the microbial synthesis of catalase and peroxidase enzymes to remove H2O2 from solution. ... -
Fe(II) stability in coastal seawater during experiments in Patagonia, Svalbard, and Gran Canaria
Hopwood, Mark J.; Santana-González, Carolina; Gallego-Urrea, Julian Alberto; Sanchez, Nicolas; Achterberg, Eric P.; Ardelan, Murat Van; Gledhill, Martha; González-Dávila, Melchor; Hoffmann, Linn; Leiknes, Øystein; Santana-Casiano, Juana Magdalena; Tsagaraki, Tatiana Margo; Turner, David (Peer reviewed; Journal article, 2020)The speciation of dissolved iron (DFe) in the ocean is widely assumed to consist almost exclusively of Fe(III)-ligand complexes. Yet in most aqueous environments a poorly defined fraction of DFe also exists as Fe(II), the ... -
Iron cycling in a mesocosm experiment in a north Patagonian fjord: Potential effect of ammonium addition by salmon aquaculture
Sanchez, Nicolas; Bizsel, Nyhayet; Iriarte, Jose Luis; Olsen, Lasse Mork; Ardelan, Murat Van (Journal article; Peer reviewed, 2019)Salmon aquaculture in Chile has been a rapidly growing industry, generating increasing inputs of organic matter and inorganic nutrients into the ecosystem. We studied the potential impacts of ammonium input by this industry ... -
Responses in the microbial food web to increased rates of nutrient supply in a southern Chilean fjord: Possible implications of cage aquaculture
Olsen, Lasse Mork; Hernandez, Klaudia; Ardelan, Murat Van; Iriarte, Jose Luis; Sanchez, Nicolas; Gonzalez, Humberto E.; Tokle, Nils Egil; Olsen, Yngvar (Journal article; Peer reviewed, 2014)ABSTRACT: Cage fish farms release the inorganic nutrients ammonium (NH4) and phosphate (PO4) into the surrounding water. The objectives of this experiment from the Comau fjord (42.2° S) in southern Chile was to study how ... -
Weddell-Scotia Confluence Effect on the Iron Distribution in Waters Surrounding the South Shetland (Antarctic Peninsula) and South Orkney (Scotia Sea) Islands During the Austral Summer in 2007 and 2008
Sanchez, Nicolas; Reiss, Christian; Holm-Hansen, Osmund; Hewes, Christopher D.; Bizsel, Kemal Can; Ardelan, Murat Van (Journal article; Peer reviewed, 2019)An oceanographic survey around the South Shetland Islands (SSI) and the South Orkney Islands (SOI) was conducted during January 2007 and February 2008, respectively, as part of the United States Antarctic Marine Living ...