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Nel corso di progetti di ricerca condotti nella sede di Venezia dell'Istituto ISMAR, sono state costituite raccolte di organismi marini animali e vegetali (invertebrati ed alghe), espressione di ambienti estuarini e marini del Nord Adriatico, e collezioni di carote di sedimento estratte per indagare le cause della subsidenza della laguna di Venezia. Il presente lavoro descrive le fasi di un percorso metodologico "multidisciplinare" che dallo studio dei campioni conduce alla loro messa in rete sul repository "Archivio Studi Adriatici". Il percorso prevede attività di laboratorio (manutenzione ed allestimento delle collezioni ed indagine tassonomica), ricerca ed analisi bibliografica sui tratti funzionali, raccolta di materiale ancillare, biodiversity informatics. Gli obiettivi del lavoro sono a) costruire una struttura facilmente accessibile alla comunità scientifica e dei cittadini utile alla conoscenza, formazione ed educazione ed alla conservazione della biodiversità e b) proporre tale metodo come strumento per rendere fruibili collezioni naturalistiche presenti in istituzioni di ricerca e non adeguatamente valorizzate.

In the framework of the VECTOR Project, biogeochemical properties and phytoplankton communities of the upper water column have been measured in three seasonal conditions at the centre of Southern Adriatic (SA). Our results, although based on few seasonal samplings, suggest a correlation between the seasonal cycles of phytoplankton and the carbonate system in SA. In consequence it confirms that shifts of carbonate system due to CO2 invasion (ocean acidification) might have great impact on the C-budget in the area.

In the framework of the VECTOR Project, biogeochemical properties and phytoplankton communities of the upper water column have been measured in three seasonal conditions at the centre of Southern Adriatic (SA). Our results, although based on few seasonal samplings, suggest a correlation between the seasonal cycles of phytoplankton and the carbonate system in SA. In consequence it confirms that shifts of carbonate system due to CO2 invasion (ocean acidification) might have great impact on the C-budget in the area.

In order to implement the WFD (EC 2000/60) a multimetric phytoplankton index was set up for transitional waters. Hulburt dominance index, bloom frequency, Menhinick diversity index and chlorophyll a concentration were tested against main environmental parameters to verify the metric responses to eutrophication. The achieved results allow to consider the proposed formulation reliable.

Il ciclo biogeochimico del carbonio è influenzato dallo scambio di CO2 tra l'atmosfera e l'idrosfera in cui il sequestro (sink) e rilascio (source) da parte della colonna d'acqua sono in gran parte influenzati dalle attività metaboliche di fotosintesi e respirazione. L'obiettivo del progetto di ricerca finanziato dal CNR (Aquatic ecosystems act as a C sink or as a C source?) è quello di descrivere i processi di incorporazione e rilascio di C in Adriatico Settentrionale lungo un gradiente di trofia e in due diverse stagioni.

In marine ecosystems, bacterioplankton affects organic matter mineralization and assimilation, mediating a significant conversion of carbon into biomass which is then transferred through the food web.

Il programma nazionale VECTOR ha come obiettivo principale lo studio degli impatti dei cambiamenti climatici sull'ambiente marino mediterraneo e il ruolo di questo bacino nel ciclo planetario della CO2. In tale ambito, nel periodo maggio-giugno 2007, è stata effettuata una campagna oceanografica lungo un gradiente latitudinale (dall'Atlantico al Mediterraneo Orientale), durante la quale è stato acquisito un data-set di parametri chimici, fisici e biologici e sono state effettuate misure concomitanti di produzione primaria e di respirazione. L'analisi dei dati riguardanti i comparti microbici, autotrofo ed eterotrofo, che svolgono un ruolo chiave nel determinare il flusso di carbonio nelle reti trofiche pelagiche nella zona fotica, ha evidenziato: o pressoché totale rimozione di nutrienti inorganici fino alla profondità del DCM con prevalenza, in questo strato, di DON e DOP; o modeste concentrazioni di biomassa fitoplanctonica in tutto il bacino e la presenza di un DCM più profondo nel bacino orientale (90 - 110 m); o la dominanza nel popolamento fitoplanctonico, in termini di biomassa, di dinoflagellati e di fitoflagellati; o la presenza di un gradiente trofico longitudinale in termini di produzione e respirazione; o la dominanza (70%) della frazione pico-fitoplanctonica nei processi di produzione primaria; o l'alta diversità chemotassonomica delle comunità fitoplanctonica e, principalmente, picoplanctonica; o la prevalenza, nei DCM di alcune stazioni, della frazione dimensionale micro- e nano-fitoplanctonica, caratterizzata soprattutto da diatomee (es. Chaetoceros); o elevati tassi di produzione primaria nel Mar Ligure non compensati dai processi di respirazione (rapporto P/R = 4,9). Sulla base dei risultati ottenuti sarà discusso il trofismo delle aree investigate in relazione ai processi di avvezione orizzontale e di mescolamento verticale delle differenti masse d'acqua, al fine di valutarne, in maniera preliminare, il ruolo nel ciclo del carbonio.

Downward fluxes of particulate matter and its biogenic components were determined in the Southern Adriatic basin below the photic layer and near the bottom utilising a mooring with sediment traps. C-export was related to the biological processes occurring in the upper water column and to the phytoplankton assemblage. At bottom, advective transport and resuspension of bottom sediment influenced the observed fluxes.

Abundance, biomass, primary production and taxonomic composition of the microalgae in the Venice lagoon are presented in order to describe the interaction between the benthic and the planktonic communities. The surface sediments appeared to be richer in biomass and diversity but the primary production resulted similar when compared with the phytoplanktonic one.not available

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International audience; This paper presents a long-term time series (1986?2005) of hydrological and biogeochemical data, both published and unpublished. Data were collected in the north-western area of the Adriatic Sea, at two stations that are considered hydrodynamically and trophically different. The time series have been statistically and graphically investigated on a monthly scale in order to find not only possible chlorophyll-a trends over time, but also links between the concentrations of chlorophyll-a and the variability in the environment, as well as trophic differences between the two areas. Basically, in both cases the statistical test results show no significant trends in either the average chlorophyll-a values or in dispersion of the data, in contrast with significant trends in temperature and salinity. The two areas have similar hydrological features, yet they present significant differences in the amount of nutrient inputs: these are in fact higher at the coastal site, which is characterized by a prevalence of surface blooms, while they are lower at the offshore station, which is mainly affected by intermediate blooms. Nonetheless, throughout the whole water column, chlorophyll-a concentrations are only slightly different. Both areas are affected by riverine discharge, though in the first case considered chlorophyll-a concentrations are also driven strongly by the seasonal cycle. Finally, the results show that the two stations are not trophically different, although some controlling factors, such as zooplankton grazing in one case and light attenuation in the other, may regulate the growth of phytoplankton.

International audience; This paper presents a long-term time series (1986?2005) of hydrological and biogeochemical data, both published and unpublished. Data were collected in the north-western area of the Adriatic Sea, at two stations that are considered hydrodynamically and trophically different. The time series have been statistically and graphically analysed on a monthly scale in order to study the annual climatologies, links between the concentrations of chlorophyll-a and the variability in the environment, trophic differences between the two areas and chlorophyll-a trends over time. Basically, the two areas have similar hydrological features, yet they present significant differences in the amount of nutrient inputs: these are in fact higher at the coastal site, which is characterized by a prevalence of surface blooms, while they are lower at the offshore station, which is mainly affected by blooms at intermediate depths. Nonetheless, throughout the whole water column, chlorophyll-a concentrations are only slightly different. Both areas are affected by riverine discharge, though chlorophyll-a concentrations are also driven strongly by the seasonal cycle at the station closer to the coast. Results show that the two stations are not trophically different, although some controlling factors, such as zooplankton grazing in one case and light attenuation in the other, may further regulate the growth of phytoplankton. In both cases no significant trends are detected in either the average chlorophyll-a values or in dispersion of the data, in contrast with significant trends in temperature and salinity.

The northern Adriatic has been recognized for many years as a region of high marine production at several trophic levels from phytoplankton to fish. The rivers draining into the northern Adriatic are the major sources of external nutrient input, especially during stratified periods. The water mass exchange between the northern region and the remainder of the essentially oligotrophic Adriatic has a great influence on the productivity and standing crops of different sub-areas. A terrigenous supply of nutrients all along the western coast via run-off influences the productivity of a relatively narrow coastal belt, and consequently the biomasses and production rates are spatially very variable. In shallow turbulent environments, like the northern Adriatic, where increased nutrient availability is episodic, the microbial or the grazing food web can alternately dominate in the carbon flow over short time periods. In spring, as a result of episodic nutrient enrichment of the euphotic zone and insufficient grazing, as a controlling factor of their population size, large-sized phytoplankton blooms occur that consequently determine a major export to the bottom via sedimentation. On the opposite, microbial food web is typical of low energy environment, mostly based on regeneration processes. As a consequence, the final fate of photosynthesised carbon can strongly change over time in the same environment as a function of the planktonic food web structures. In the framework of VECTOR project ("VulnErabilità delle Coste e degli ecosistemi marini italiani ai cambiamenti climaTici e loro ruolO nei cicli del caRbonio mediterraneo") a re-analisys of the entire available data set of parameters relevant in driving C fluxes and export rates has been planned to provide conceptual models and appropriate parametrizations to modelers, with the aim to hindcast and forecast ecosystem scenarios at the basin scale.