11 research outputs found

    Disturbance and community pattern of polychaetes inhabiting Valle Magnavacca (Valli di Comacchio, Northern Adriatic Sea, Italy)

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    Polychaete community structure in Valle Magnavacca, the largest basin of the Valli di Comacchio (Northern Adriatic Sea) lagoonal ecosystem, was analyzed in a three-year study. Three shallow-water stations were sampled at about 3-month intervals. Univariate and multivariate analyses were utilized to investigate community structure changes in relation to natural and man-induced disturbance. The polychaete community at station 3, in the central area of the lagoon, was the most disturbed, while that of station 2 was the most well structured. We hypothesize that polychaete community structure results from regular seasonal disturbances which lead to almost predictable fluctuations in species abundance. Superimposed on these regular cycles are acute disturbance events that further reduce species abundance or exclude species from the habita

    Response of macrobenthic communities to an hydraulic intervention in an enclosed lagoon (Valle di Gorino, northern Italy)

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    In order to assess the recovery of this lagoon, the macrobenthic assemblages in the Valle di Gorino, Italy, were studied throughout a two years period, i.e., before and after the opening of a flood gate. Three station were located along a gradient of confinement, and sampled for macrofauna, water and sedimentary parameters. Analyses were performed through univariate and multivariate techniques. The macrobenthic assemblages were characterized by a small total number of species, strong dominance in number by a few of these species, and low diversity, but changes in community structure and composition were clearly recognizable. Significant negative correlations were found between macroalgae and macrobenthic community attributes. The altered hydrological regime due to the opening of the flood gate disrupted macroalgal cycles and altered the related macrofaunal successional dynamics: species linked to the macroalgal degradation phase became dominant throughout the Valle. After the intervention, all areas exhibited similar species composition and abundances, and appeared to be in a permanently disturbed condition. A rescaling of environmental conditions repositioned species roles in the community: those species which were typical of a certain phase of the former successional progression, were successively dominating the whole lagoon, irrespective of time and the estuarine gradient. After the intervention, the spatial and temporal distribution of macrobenthic taxa was under the control of factors linked to organic enrichment of the sediment

    Recovery of the macrobenthic community in the Valli di Comacchio, northern Adriatic Sea, Italy.

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    The macrobenthic community structure of the Valli di Comacchio (Northern Italy) was described in order to assess the ecological conditions of the main basins through 2001. In addition, the biotic data set gathered in 1997-98 was compared to achieve an estimation of the eventual recovery of the lagoonal benthic assemblages. Four permanent sites (P1, M4, M5 and M6), located along a gradient of sediment texture and confinement, and representing 4 different areas of the lagoon, were sampled quarterly in 2001 for macrofauna and sedimentary variables (organic content, phytobenthic chlorophyll-a, depth of RPDL), and fortnightly for water variables (temperature, salinity, dissolved oxygen and planktonic chlorophyll-a). Water and sedimentary variables were typical of eutrophic areas. A total of 52 macrobenthic taxa were identified and, on the basis of the species collected, differences in faunal distribution among the 4 areas were recognized, although less marked than in previous studies. Sediment trophic status and its seasonal dynamics in the Valli were crucial in determining species distribution among the different areas. The comparison between 1997-98 and 2001 biotic data indicated that conditions in the lagoon had improved, especially in the formerly most impaired, central area (M6). In the Valli di Comacchio, the recovery of benthic communities after severe disturbance will probably take longer, even if sewage discharges have been removed 11 yr ago. Secondary disturbance due to scarce water circulation, sharp temperature and salinity fluctuations, release of toxic substances from sediments influenced animal assemblages along spatial and temporal scales. The interplay of these variables probably caused deviations from the expected improvement in benthic conditions. Nevertheless, clear signs of amelioration, particularly at the previously most impaired area, were detectabl

    A survey on a persistent greenish bloom in the Comacchio Lagoons (Ferrara, Italy)

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    The Comacchio lagoonal system has been affected for years by a persistent phytoplanktonic bloom which makes the waters greenish. Surveys carried out from April 1995 to February 1996 showed that this bloom was caused by a Synechococcus sp. and by an Eustigmatophycean belonging to the genus Nannochloropsis. However, while the Synechococcus sp. was mainly present in the summer, Nannochloropsis was always present with constant density values. Moreover, this species shows many ultrastructural features and a pigment composition similar to those of Nannochloropsis spp. and reproduces by autospores. The 18S rRNA gene sequence of this strain is identical to those of five strains of Nannochloropsis gaditana. In this paper, besides phytoplankton (including picophytoplankton), we also report the data of the main chemico-physical parameters. Among them, the salinity and nutrient values showed an anomalous seasonal trend

    Recovery of the macrobenthic community in the Valli di Comacchio, northern Adriatic Sea, Italy

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    The macrobenthic community structure of the Valli di Comacchio (northern Italy) was described in order to assess the ecological conditions of the main basins through 2001. In addition, the biotic data set gathered in 1997-1998 was compared to achieve an estimation of the eventual recovery of the lagoonal benthic assemblages. Four permanent sites (PI, M4, M5 and M6), located along a gradient of sediment texture and confinement, and representing four different areas of the lagoon, were sampled quarterly in 2001 for macrofauna and sedimentary variables (organic content, phytobenthic chlorophyll-a, depth of the redox potential discontinuity layer), and fortnightly for water variables (temperature, salinity, dissolved oxygen and planktonic chlorophyll-a). Water and sedimentary variables were typical of eutrophic areas. A total of 52 macrobenthic taxa were identified and, on the basis of the species collected, differences in faunal distribution among the four areas were recognized, although less marked than in previous studies. Sediment trophic status and its seasonal dynamics in the Valli were crucial in deter-mining species distribution among the different areas. The comparison between 1997-1998 and 2001 biotic data indicated that conditions in the lagoon had improved, especially in the formerly most impaired, central area. In the Valli di Comacchio, the recovery of benthic communities after severe disturbance will probably take longer, even if sewage discharges have been removed I I years ago. Secondary disturbance due to scarce water circulation, sharp temperature and salinity fluctuations, release of toxic substances from sediments influenced animal assemblages along spatial and temporal scales. The interplay of these variables probably caused deviations from the expected improvement in benthic conditions. Nevertheless, clear signs of amelioration, particularly at the previously most impaired area, were detectable.La structure de la communauté macrobenthique des Valli di Comachio est décrite pour définir les conditions écologiques des principaux bassins en 2001. Ces données sont comparées à celles de 1997–1998 pour mettre éventuellement en lumière une restauration de cet écosystème. Quatre stations permanentes localisées selon un gradient de texture sédimentaire et de confinement et représentant quatre aires différentes du système lagunaire ont été échantillonnées. Les mesures ont été effectuées chaque trimestre pour la macrofaune et le sédiment (contenu organique, chlorophylle a du phytobenthos, couche de discontinuité du potentiel redox) et chaque quinzaine pour la masse d’eau (température, salinité, oxygène dissous et chlorophylle a planctonique). Toutes ces variables sont caractéristiques d’aires eutrophes. Un total de 52 taxons a été identifié pour le macrobenthos. Des différences apparaissent entre les quatre zones quoique moins marquées que lors d’études précédentes. L’état trophique du sédiment et la dynamique saisonnière constituent des variables cruciales pour la distribution des espèces. Les conditions dans la lagune se sont améliorées depuis 1997–1998, particulièrement dans la zone centrale. Dans les Valli di Comachio, la restauration des communautés benthiques après une perturbation sévère demandera du temps, même si la décharge des effluents a été arrêtée il y a onze ans. Une perturbation secondaire due à la faiblesse de la circulation, aux variations brusques de température et de salinité et à l’apport de substances toxiques originaires du sédiment influence les communautés animales. Les interactions entre ces facteurs expliquent les déviations par rapport à la restauration espérée des conditions benthiques. Cependant, des signes clairs d’amélioration apparaissent, particulièrement dans la zone préalablement la plus altérée

    Mental Health Sensing Using Machine Learning

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    Using audio and text data from multiple sources, we evaluated the viability of using machine and deep learning to identify depression and anxiety. Machine learning methods using sub-clip boosting achieved an F1 score of 0.81 for depression and 0.83 for anxiety. Our convolutional neural networks and long-term short term memory models achieved F1 scores of 0.55 and 0.68 respectively for depression. As feature engineering, we used topological data analysis to create Betti curves in our machine learning pipeline. Furthermore, we developed a pipeline to generate text messages with deep learning models, for data augmentation purposes
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