Diel observations on populations of Dinophysis and Alexandrium spp. (Dinophyceae) from the NW Adriatic Sea

Quanti-qualitative changes in Dinophysis and Alexatidrium populations from the Gulf of Venice NW Adriatic Sea - were studied on a short time scale (44 h cycles). Under hydrographic conditions of marked thermohaline stratification (July 1995), D. sacculus populations assembled in the surface waters (12 24 yt isopycnals). Division processes took place mostly in the early hours of the morning and at 14:00 h, 4 to 10 % of the population consisted of morphotypes of reduced size (possibly gametes resulting from successive cell divisions). Similar percentages were also observed in October for D. caudata, with a maximum division between 06:00 h and 10:00 h. During this month, coexisting populations of Alexandrium cf. fundyense and A. cf. tamarense displayed rhythmic changes in cell density that slightly differed from those exhibited in July by A. pseudogonyaulax, suggesting a circadian control of the cell cycle rather than a response to hydrographic changes

Diel observations on populations of Dinophysis and Alexandrium spp. (Dinophyceae) from the NW Adriatic Sea

Quanti-qualitative changes in Dinophysis and Alexatidrium populations from the Gulf of Venice NW Adriatic Sea - were studied on a short time scale (44 h cycles). Under hydrographic conditions of marked thermohaline stratification (July 1995), D. sacculus populations assembled in the surface waters (12 24 yt isopycnals). Division processes took place mostly in the early hours of the morning and at 14:00 h, 4 to 10 % of the population consisted of morphotypes of reduced size (possibly gametes resulting from successive cell divisions). Similar percentages were also observed in October for D. caudata, with a maximum division between 06:00 h and 10:00 h. During this month, coexisting populations of Alexandrium cf. fundyense and A. cf. tamarense displayed rhythmic changes in cell density that slightly differed from those exhibited in July by A. pseudogonyaulax, suggesting a circadian control of the cell cycle rather than a response to hydrographic changes

Recent Trends Towards Oligotrophication of the Northern Adriatic: Evidence from Chlorophyll a Time Series

Abstract The results of the updated and quality-checked data base of field observations on chlorophyll a (Chl a) collected in the period 1970-2007 in the Northern Adriatic Sea are presented. From the last decade, SeaWiFS satellite information was also considered. Results demonstrate a global tendency towards Chl a reduction in the period of investigation, which is more marked in the eutrophic area under the influence of the Po River. In the rest of the basin, which presents meso- or oligotrophic characteristics, long-term changes are more difficult to detect. The long-term field dataset can be divided into two periods: the last decade characterized by the strong decrease observed in the whole northern Adriatic and the earlier period with no or slight increase. The recent substantial reduction of Chl a concentrations is confirmed all over the basin (−0.11 mg m−3 year−1) from satellite-derived information. Results are consistent with recently evidenced decrease in concentrations of phosphate and ammonia and point to the existence of oligotrophication in the Northern Adriatic. Results indicate forcefully that the still common perception of the Adriatic Sea as a very eutrophic basin is no longer appropriate, at least for its northern part and in recent years

Spatial variability of phytoplankton, nutrients and new production estimates in the waters around Svalbard

Phytoplankton dynamics and carbon input into Arctic and sub-Arctic ecosystems were investigated around Svalbard, in summer 1991. Phytoplankton biomass, species composition and dissolved nutrient concentrations were analysed from water samples collected along seven transects. Phytoplankton biomass was low especially to the north (Chlorophyll-a mean 0.3 pg 1- '), where flagellates dominated the communities and only ice-diatoms were present. To the west, the phytoplankton composition was representative of a summer Atlantic community, in a post-bloom state. Zooplankton grazing, mainly by copepods, appeared to be the main control on biomass to the west and north of Svalbard. In the Barents Sea (east of Svalbard), an ice edge bloom was observed (Chlorophyll-a max. 6.8 pgl-') and the ice edge receded at a rate of approximately 1 1 km day-'. The phytoplankton community was represented by marginal ice species, especially Phaeocystis poucherii and Chaeroceros socialis. South of the ice edge, Deep Chlorophyll Maxima (DCM) were observed, as surface waters became progressively nutrient-depleted. In these surface waters, the phytoplankton were predominantly auto- and heterotrophic flagellates. Carbon production measurements revealed high net production (new and regenerated) to the north of the Barents Sea Polar Front (BSFW); it was especially high at the receding ice edge (reaching 1.44gC m-'day-'). To the south, a low level of production was maintained, mainly through regenerative processes

Recent trends towards oligotrophication of the Northern Adriatic: evidence from chlorophyll a time series

The results of the updated and quality-checked data base of field observationson chlorophyll a (Chl a) collected in the period 1970-2007 in the Northern Adriatic Sea are presented. From the last decade, SeaWiFS satellite information was also considered. Results demonstrate a global tendency towards Chl a reduction in the period of investigation, which is more marked in the eutrophic area under the influence of the Po River. In the rest of the basin, which presents meso- or oligotrophic characteristics, long-term changes are more difficult to detect. The long-term field dataset can be divided into two periods: the last decade characterized by the strong decrease observed in the whole northern Adriatic and the earlier period with no or slight increase. The recent substantial reduction of Chl a concentrationsis confirmed all over the basin (-0.11 mg m-3 year-1) from satellite-derived information. Results are consistent with recently evidenced decrease in concentrations of phosphate and ammonia and point to the existence of oligotrophication in the Northern Adriatic. Results indicate forcefully that the still common perception of the Adriatic Sea as a very eutrophic basin is no longer appropriate, at least for its northern part and in recent years

Utilizzo del fitoplancton per la valutazione della qualità ambientale della Laguna di Cabras (Sardegna occidentale, Italia)

I dati di abbondanza e composizione fitoplanctonica e di clorofilla a della Laguna di Cabras (Sardegna occidentale), raccolti con cadenza da quindicinale a mensile dal 1999 al 2009 in tre stazioni collocate lungo un gradiente salino, sono stati utilizzati per valutare la qualità ambientale attraverso l’applicazione di un indice multimetrico sviluppato da FACCA et al. (2011). I risultati hanno indicato una condizione della laguna complessivamente scadente (poor), principalmente dovuta ad un importante arricchimento in nutrienti, e hanno inoltre evidenziato che non esistono significative differenze tra le stazioni considerate. The multimetric index developed by FACCA et al. (2011) was applied to valuate the ecological quality of the Cabras Lagoon (western Sardinia, Italy). The database was composed by data collected from 1999 to 2009, at intervals from fortnightly to monthly, on phytoplankton abundances and species composition, and chlorophyll a in three stations sited along a salinity gradient. The preliminary results showed an overall poor condition of the lagoon, mainly due to nutrient enrichment; moreover, no significant differences were noticed among stations

The project EcoNAOS: vision and practice towards an open approach in the Northern Adriatic Sea ecological observatory

The Open Science approach delineates high and inspiring principles. In order to really root them into the scientific community, a cultural shift must occur that can be fostered and achieved mainly through the development of practical case studies. This is particularly relevant in the field of ecology, a highly multidisciplinary science, where the Open Science issue has become a matter of discussion only in very recent years. In particular, in the context of long-term ecological research, enabling open sharing of in-situ and derived long-term ecological data is required to advance research and education in the European and global networks. The creation of marine ecological observatories, able to arrange and maintain integrated, harmonized and coherent long-term ecological observations, is stressed as a relevant step at the European level, for sustaining European marine policies. The Italian national flagship project RITMARE ("Italian research for the sea", http://www.ritmare.it/en/) fostered the development of a marine ecological observatory in the Northern Adriatic Sea (NAS), one of the 25 research parent sites belonging to the Italian Long-Term Ecological Research Network (LTER-Italy, http://www.lteritalia.it), through a dedicated research line. Within this context, we developed a specific task, aimed at testing and applying the Open Science approach to the NAS ecological observatory: "EcoNAOS - Ecological Northern Adriatic Open Science Observatory System". We present our plans and ideas for the application of the Open Science principles, starting from the 50-year ecological dataset of plankton and related biogeochemical parameters collected in the NAS, mainly in the Gulf of Venice. We introduce each of the different steps needed for "opening science": research ideas statement, raw data collection, data harmonization (structural, syntactic and semantic), ancillary data collection/recovery and metadatation, data and metadata publication, software publication, publication of results, and data citation. In order to share different expertise and include different points of view as essential outcomes themselves, researchers from the field of LTER and data management were involved in EcoNAOS since its start. Our final goal is to demonstrate that a change of vision is possible, leading from "publishing ASAP" to "sharing data and information and collaborating ASAP"