Effects of Paramuricea clavata (Risso, 1826) (Anthozoa: Plexauridae) forests on settlement of benthic species: an experimental approach

Rationale: Coralligenous habitat is considered the second most important subtidal “hot spot” of species diversity in the Mediterranean Sea after the Posidonia oceanica meadows. It can be defined as a typical Mediterranean biogenic hard bottom, mainly produced by the accumulation of calcareous encrusting algae that, together with other builder organisms, form a multidimensional framework with a high micro-spatial variability. The development of this habitat depends on physical factors (i.e. light, hydrodynamism, nutrients, etc.), but also biologic interactions can play a relevant role in structuring the benthic assemblages. This great environmental heterogeneity allows several different assemblages to coexist in a reduced space. One of the most beautiful is that characterised by the Mediterranean gorgonian Paramuricea clavata (Risso, 1826) that can contribute to above 40% of total biomass of the community and brings significant structural complexity into the coralligenous habitat. In sites moderately exposed to waves and currents, P. clavata can form high-density populations (up to 60 colonies m-2) between 20 – 70 m in depth. Being a suspension feeder, where it forms dense populations, P. clavata plays a significant role in transferring energy from planktonic to benthic system. The effects of the branched colonies of P. clavata could be comparable to those of the forests on land. They can affect the micro scale hydrodynamism and light, promoting or inhibiting the growth of other species. Unfortunately, gorgonians are threatened by several anthropogenic disturbance factors (i.e. fishing, pollution, tourism) and by climatic anomalies, linked to the global changes, that are responsible of thermal stress, development of mucilage and enhanced pathogens activity, leading to mass mortality events in last decades. Till now, the possible effects of gorgonian forest loss are largely unknown. Our goal was to analyse the ecological role of these sea fan forests on the coralligenous benthic assemblages. Experimental setup and main results: The influence of P. clavata in the settlement and recruitment of epibenthic organisms was analysed by a field experiment carried out in two randomly selected places: Tavolara island and Portofino promontory. The experiment consisted in recreate the presence and absence of the gorgonian forest on recruitment panels, arranged in four plots per type (forested and non-forested), interspersed each other, and deployed at the same depth. On every forested panel 3 gorgonian colonies about 20 cm height were grafted with the use of Eppendorf tubes and epoxy resin bicomponent simulating a density of 190 sea fans per m-2. This density corresponds to a mean biomass of 825 g DW m-2,3 which is of the same order of magnitude of the natural high-density populations. After about 4 months, the panels were collected and analysed in laboratory in order to estimate the percent cover of all the species that have colonized the substrata. The gorgonian forest effects were tested by multivariate and univariate permutational analyses of the variance (PERMANOVA). Recruited assemblages largely differed between the two study sites, probably due to different environmental conditions including water quality and turbidity. On overall, the presence of P. clavata reduced the settlement and recruitment of several algae: the shadow caused by the gorgonian might reduce light availability and therefore their growth. This effect might be greater in places where the waters are on average more clear, since at Portofino it is less visible and could be masked by the high turbidity of the water. The same pattern was registered for forams, more abundant outside gorgonian forest, probably linked with algal distribution, shadowing effect or alimentary competition. The last one hypothesis could be valid also for serpulids polychaetes that growth mainly on non-forested panels. An opposite trend, was showed by a species of bryozoan and by an hydroid that is facilitated by the presence of P. clavata, probably because it attenuates irradiance level and hydrodynamism. Species diversity was significantly reduced by the presence of P. clavata forests at both sites. This seems in contrast with what we expected, but the result may be influenced by the large algal component on non-forested panels. The analysis confirmed the presence of differences in the species diversity among plots and between sites respectively due to natural high variability of the coralligenous system and to different local environment conditions. The reduction of species diversity due to the presence of gorgonians appeared related to a worst evenness rather than to less species richness. With our experiment it is demonstrated that the presence of P. clavata forests can significantly alter local coralligenous assemblages patterns, promoting or inhibiting the recruitment of some species, modifying trophic relationships and adding heterogeneity and complexity to the habitat. Moreover, P. clavata could have a stabilising effect on the coralligenous assemblages.

Effect of Paramuricea clavata (Risso, 1826) "forest" on the benthic populations of Tremiti Islands Effetto "foresta" di Paramuricea clavata (Risso, 1826) sui popolamenti bentonici delle Isole Tremiti

Mediterranean coralligenous habitats are biogenic reefs characterised by high species diversity and built mainly by encrusting calcareous red algae, growing in dim light conditions. The global climate change and several human activities may threaten species living in these habitats, especially some of those that are considered particularly relevant in structuring and in maintaining the complexity and diversity of the benthic assemblages. Among them, the red gorgonian, Paramuricea clavata (Risso, 1826), which can form dense populations, in the last decades showed worrying mass mortality events. Understand the role of this “animal forests” in the coralligenous assemblages is of fundamental importance in order to design appropriate monitoring programs and conservation policies, especially in the marine protected areas. For this purpose, benthic assemblages were studied in presence and absence of red gorgonians at two sites at the Tremiti islands. Overall, the benthic assemblages significantly differed among sites, nevertheless in both places, clear differences between assemblages associated and not associated to the gorgonian forests were found. In particular, encrusting corallinered algae were significantly more abundant in the gorgonian understories at both sites. This result indicates that the gorgonians may promote the development of calcareous algae, which are the main builders of the coralligenous habitats. Moreover species diversity resulted higher in the assemblages associated to the gorgonians. The present study highlights the role of Paramuricea clavata as a relevant ecosystem engineer in the coralligenous habitats.

Proposta di traduzione del romanzo di Antonio Ventura: Un amor en tres tiempos

Il presente elaborato è dedicato alla proposta di traduzione, dallo spagnolo in italiano, del romanzo di Antonio Ventura "Un amor en tres tiempos". Protagonisti della storia sono Emile e Alexandra e il sentimento amoroso che li lega lungo i ventotto anni in cui essa si sviluppa. Attraverso le loro emozioni e le loro paure, Ventura ci fa entrare, in modo mirabile, nel mondo dei due protagonisti, con un’approfondita indagine introspettiva nella loro vita, seguendo l’evoluzione di un sentimento che si modula, nei tre tempi cui fa accenno il titolo, dall’infanzia, quindi l’adolescenza, infine, l’età adulta. Oltre all’introduzione e alle conclusioni, il lavoro si compone di cinque capitoli: il primo è dedicato all’autore che ho avuto modo di conoscere di persona e di incontrare più volte, sia in Italia sia in Spagna, e con cui ho mantenuto uno stretto rapporto di collaborazione lungo tutto il percorso traduttivo; nel secondo sviluppo la mia analisi del testo focalizzandomi su trama, paratesto, temi, personaggi, narratore, tempo e spazio della storia e stile dell’autore; il terzo, che contiene la proposta di traduzione, è seguito dal commento alla traduzione, argomento sia del quarto capitolo, di carattere teorico, che del quinto, in cui si analizzano più da vicino i problemi traduttivi riscontrati e le strategie messe in atto per risolverli.

Parole in forma di gatto. Gatos y leones di Xose Antonio Neira Cruz: proposta di traduzione

El presente trabajo tiene el objetivo de dar a conocer a los jóvenes lectores italianos la obra narrativa y el estilo literario de Xosé Neira Cruz, uno de los autores más representativos de la literatura infantil contemporánea gallega y española. Con este fin, se ha traducido y analizado uno de los libros más famosos del autor, Gatos y leones, finalista en el concurso catalán Lola Anglada poco tiempo después de su primera aparición. El trabajo consta de cinco capítulos. En el primero, se presenta al autor, detallando su vida, su estilo y sus obras, a través de una entrevista que es el fruto del encuentro con el autor en Santiago de Compostela (enero de 2015). En el segundo capítulo, se ofrece un análisis del texto original, profundizando los aspectos más significativos de la obra en general y de cada cuento en particular (trama, narrador, personajes principales, tiempo y espacio, estilo y temas). El tercer capítulo está dedicado a la figura del gato, protagonista indiscutible de los cuentos que forman el libro e inspiración de la obra literaria y artística de muchos escritores, poetas y pintores, a lo largo de los siglos. En el cuarto capitúlo se encuentra la propuesta de traducción, en la que se ha preservado el formato del original y se han añadido ilustraciones para enriquecer el texto. Finalmente, en el quinto capítulo, se expone la metodología adoptada para traducir el texto y se comentan las estrategias empleadas a lo largo del proceso de traducción para resolver los problemas que han surgido.

Traduzione dall’italiano al francese di un brano tratto dal romanzo "Fuori piove, dentro pure, passo a prenderti?" di Antonio Dikele Distefano

Dans ce mémoire, il a été question pour moi de faire la traduction, de l’italien vers le français, d’un extrait de l’œuvre "Fuori piove, dentro pure, passo a prenderti ?" de Antonio Dikele Distefano, qui s’intitule "Kaaris, Or noir". C’est un texte dans lequel l’auteur parle de la discrimination dont il est victime et de la rigueur de ses parents, sa mère en particulier. On met également en exergue le rejet social, car c’est plus ou moins le thème central de l’œuvre. Ainsi, j’ai organisé et articulé mon travail selon les techniques de commentaire, d’analyse et de traduction qui m’ont été enseignées tout au long de mon parcours académique. Vous en trouverez et en apprécierez l’illustration dans les pages qui suivent.

Ruolo della gorgonia Paramuricea clavata (Risso 1826) nei popolamenti epibentonici coralligeni dell'Isola d'Elba

The red gorgonian Paramuricea clavata is considered a key species in Mediterranean coralligenous habitats and, when present at high density, its colonies may develop “gorgonian forests”, which are three-dimensional structures that increase habitat complexity. Mediterranean coralligenous habitats support high biodiversity but the structure and heterogeneity of communities can be strongly modified by several kinds of human-derived impacts. The global environmental change and human activity could threaten the coralligenous habitats and during the last few decades, Mediterranean suspension feeders have been involved in mass mortality events, in which P. clavata was one of the most affected. Without the complex three-dimensional structures formed by P. clavata, many benthic species may have not adequate sheltering and feeding opportunities. The aim of the present study was to investigate the ecological role of Paramuricea clavata in coralligenous habitats by comparing epibenthic assemblages established inside and outside gorgonian forests. This study was carried out in four sites randomly chosen, along the south-east coast of Elba island (north-western Mediterranean). The structure of the epibenthic assemblages were significantly different between area with and without gorgonians. Main differences concern very important taxa in the coralligenous bioconstruction processes like the encrusting red algae, Peyssonnelia spp. and Halimeda tuna, which were more abundant in presence of gorgonians. On the contrary, algal turf, mucilaginous algae and the invasive seaweed Caulerpa cylindracea were more abundant in areas without P. clavata. The presence of gorgonians may have a positive effect also on species diversity. The results of this study highlight the ecological role of P. clavata in the coralligenous habitats.