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DatoValore
TitleDissolved organic matter and microbial food web interactions in the marine environment: the case of the Adriatic Sea
AbstractThe sources, characteristics and fate of the dissolved organic matter (DOM) in marine ecosystems are reviewed, with particular emphasis on processes relevant to the northern Adriatic Sea. This semi-enclosed basin receives large riverine discharges that strongly affect its trophic dynamics. The high organic load, which results from both autochtonous and allochtonous sources, is responsible for anoxia and massive aggregate formation. The general characteristics of the microbial food web and its role in the cycling of carbon are critically evaluated. Factors affecting DOM uptake by bacteria, including DOM diagenesis and molecular size, nutrient availability, the effect of temperature and the abiotic alterations of DOM are discussed. Possible causes for DOM seasonality are suggested. A restricted bacterial uptake due to scarce inorganic phosphorus availability, along with strong allochtonous inputs of refractory compounds and strong water stratification in summer, appear to be the most important factors. Finally, the distribution of organic carbon between dissolved and colloidal components and the role of colloids in the aggregation phenomena in marine systems are briefly outlined, and hypotheses for the formation of macroaggregates in the northern Adriatic are reviewed.
SourceInternational journal of environment and pollution 13 (1), pp. 473–494
KeywordsAdriatic Seadissolved organic mattermicrobial food webs
JournalInternational journal of environment and pollution
EditorInterscience Enterprises., Geneva,
Year2000
TypeArticolo in rivista
AuthorsPuddu, Alberto; Zoppini, Annamaria; Pettine, Maurizio
Text338607 2000 Scopus 2 s2.0 0033723735 Adriatic Sea dissolved organic matter microbial food webs Dissolved organic matter and microbial food web interactions in the marine environment the case of the Adriatic Sea Puddu, Alberto; Zoppini, Annamaria; Pettine, Maurizio Istituto di Ricerca sulle Acque, Italy The sources, characteristics and fate of the dissolved organic matter DOM in marine ecosystems are reviewed, with particular emphasis on processes relevant to the northern Adriatic Sea. This semi enclosed basin receives large riverine discharges that strongly affect its trophic dynamics. The high organic load, which results from both autochtonous and allochtonous sources, is responsible for anoxia and massive aggregate formation. The general characteristics of the microbial food web and its role in the cycling of carbon are critically evaluated. Factors affecting DOM uptake by bacteria, including DOM diagenesis and molecular size, nutrient availability, the effect of temperature and the abiotic alterations of DOM are discussed. Possible causes for DOM seasonality are suggested. A restricted bacterial uptake due to scarce inorganic phosphorus availability, along with strong allochtonous inputs of refractory compounds and strong water stratification in summer, appear to be the most important factors. Finally, the distribution of organic carbon between dissolved and colloidal components and the role of colloids in the aggregation phenomena in marine systems are briefly outlined, and hypotheses for the formation of macroaggregates in the northern Adriatic are reviewed. Focusing on the Adriatic Sea, the composition of dissolved organic matter DOM is described, and DOM autochtonous and allochtonous sources are identified. Also reviewed are the microbial food web and the DOM cycle, and factors affecting DOM uptake by microorganisms, such as diagenesis and molecular size, nutrient availability, marine water temperature, and abiotic alterations of DOM. Dissolved organic matter is particularly problematic in the Adriatic Sea, which is semi enclosed. The DOM accumulation in the northern basin is attributed to an increase in the freshwater residence time, the setting up of strong vertical stratification, and eddy circulation in summer. The data suggest that the phenomenon of macroaggregate production in the Adriatic is due to two separate processes the accumulation of DO and its transformation from dissolved and colloidal to gelatinous compounds. The DOM accumulation appears to be the result of an inefficient uptake by bacteria. 13 Published version http //www.scopus.com/record/display.url eid=2 s2.0 0033723735 origin=inward Articolo in rivista Interscience Enterprises. 0957 4352 International journal of environment and pollution International journal of environment and pollution Int. j. environ. pollut. maurizio.pettine PETTINE MAURIZIO alberto.puddu PUDDU ALBERTO annamaria.zoppini ZOPPINI ANNAMARIA