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DatoValore
TitleRelazioni tra batteri eterotrofi e fitoplancton nel Mar Piccolo di Taranto
AbstractSeveral studies have already been carried out to characterize heterotrophic bacteria and phytoplankton communities in ocean sites and in different coastal areas of temperate, tropical and polar zones. Mar Piccolo of Taranto (Ionian Sea) is a semi-enclosed basin subject to pollution and receives a considerable amount of sewage and industrial waste. The aims of this work was to analyse the qualitative and quantitative composition of heterotrophic bacteria and phytoplankton communities and the interactions between these two planktonic components. Samples of sea-water were collected monthly from September 2006 to August 2007 in two stations of the Mar Piccolo at the surface and bottom layers. Among the Gram-negative bacteria, the predominant genus were Aeromonas, Photobacterium e Pseudomonas. Gram-positive bacilli were abundant at all sampling points. Among pigmented bacteria, Flavobacterium was predominant. As regards phytoplankton communities, quantitative data evidenced high abundance values in the spring time and they were characterized by the dominance of diatom and phytoflagellate groups. Dinoflagellates and coccolithophorids accounted only for low percentage values. During the sampling period, diatoms were dominant with high cell densities in the spring and were mainly represented by Pseudo-nitzschia spp., Chaetoceros spp., Cylindrotheca closterium, and Thalassiosira sp. Indeed, phytoflagellates, mainly represented by the undetermined forms < 10 ?m and by cryptophyceans, had a wider distribution over time. As regards the interactions between bacteria and phytoplankton, our data must be considered preliminary, but they seemed to evidence that phytoplanktonic spring bloom could be probably responsible for the availability of organic matter for bacterial populations. But, further studies will evaluate whether the balance in time between the positive dissolved factors (nutrients from phytoplankton bloom) and the negative particulate factors (grazing) could be considered to be a major determinant of the temporal fluctuations of bacterial density in Mar Piccolo.
SourceWorkshop Progetto Vector-GeoItalia 2007, Rimini, 10-11 settembre
Keywordsheterotrophic bacteriaphytoplanktonMar Piccolo of Taranto.
Year2007
TypeAbstract in atti di convegno
AuthorsCavallo R.A., Acquaviva M.I., Narracci M., Stabili L., Caroppo C.
Text99948 2007 heterotrophic bacteria phytoplankton Mar Piccolo of Taranto. Relazioni tra batteri eterotrofi e fitoplancton nel Mar Piccolo di Taranto Cavallo R.A., Acquaviva M.I., Narracci M., Stabili L., Caroppo C. Istituto Ambiente Marino Costiero IAMC CNR Sezione di Taranto, Italia Published version Workshop Progetto Vector GeoItalia 2007 Rimini 10 11 settembre Nazionale Contributo Several studies have already been carried out to characterize heterotrophic bacteria and phytoplankton communities in ocean sites and in different coastal areas of temperate, tropical and polar zones. Mar Piccolo of Taranto Ionian Sea is a semi enclosed basin subject to pollution and receives a considerable amount of sewage and industrial waste. The aims of this work was to analyse the qualitative and quantitative composition of heterotrophic bacteria and phytoplankton communities and the interactions between these two planktonic components. Samples of sea water were collected monthly from September 2006 to August 2007 in two stations of the Mar Piccolo at the surface and bottom layers. Among the Gram negative bacteria, the predominant genus were Aeromonas, Photobacterium e Pseudomonas. Gram positive bacilli were abundant at all sampling points. Among pigmented bacteria, Flavobacterium was predominant. As regards phytoplankton communities, quantitative data evidenced high abundance values in the spring time and they were characterized by the dominance of diatom and phytoflagellate groups. Dinoflagellates and coccolithophorids accounted only for low percentage values. During the sampling period, diatoms were dominant with high cell densities in the spring and were mainly represented by Pseudo nitzschia spp., Chaetoceros spp., Cylindrotheca closterium, and Thalassiosira sp. Indeed, phytoflagellates, mainly represented by the undetermined forms < 10 m and by cryptophyceans, had a wider distribution over time. As regards the interactions between bacteria and phytoplankton, our data must be considered preliminary, but they seemed to evidence that phytoplanktonic spring bloom could be probably responsible for the availability of organic matter for bacterial populations. But, further studies will evaluate whether the balance in time between the positive dissolved factors nutrients from phytoplankton bloom and the negative particulate factors grazing could be considered to be a major determinant of the temporal fluctuations of bacterial density in Mar Piccolo. Abstract in atti di convegno carmela.caroppo CAROPPO CARMELA loredana.stabili STABILI LOREDANA mariaimmacolata.acquaviva ACQUAVIVA MARIA IMMACOLATA marcella.narracci NARRACCI MARCELLA rosaanna.cavallo CAVALLO ROSA ANNA TA.P04.002.001 Fascia Costiera e Ambienti di Transizione analisi strutturale e funzionale delle componenti biotiche ed abiotiche degli ecosistemi per lo sviluppo sostenibile delle attivita