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Titre :
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Seasonal variation of nitrification along a salinity gradient in an urban estuary
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Auteurs :
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A. Iriarte ;
A. De La sota ;
E. Orive
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Type de document :
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article/chapitre/communication
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Année de publication :
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1998
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Format :
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p. 115-126
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Langues:
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= Anglais
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Catégories :
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QUALITE DE L'EAU
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Mots-clés:
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NITRIFICATION
;
ESTUAIRE
;
SALINITE DE L'EAU
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Résumé :
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The rates of water column nitrification measured as nitrapyrin-sensitive rates of bicarbonate assimilation were monitored along the salinity gradient of the estuary of the River Nervi6n (Bay of Biscay) from January to November 1993. Highest nitrapyrin-sensitive rates of bicarbonate assimilation were found in the deep layer at stations located in the inner estuary during summer and autumn, coinciding with dissolved oxygen concentrations generally lower than 1 mg O 1. Possible explanations for this spatial distribution pattern are discussed. Axial and depth distribution of ammonia, nitrite and nitrate suggests that in the deep layer of the inner zone of the estuary nitrification and nitrate and nitrite reduction are occurring concurrently. Nitrification showed a significant positive correlation with temperature, but this correlation was not very strong. It is argued that the wash out of nitrifying bacteria by rainfalls also plays a role in the seasonal variation of nitrification rates.
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Source :
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Hydrobiologia, vol.362
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