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Benthic ecosystem functioning
No full textThe main aim of this doctoral research project was to assess the benthic ecosystem functioning in areas subjected to multiple and diffuse impacts. The Aeolian Islands, originated by the volcanic activity and characterised by continuous gas emissions and presence of thermal vents on the surrounding seabed, represent a good natural laboratory for global warming and carbon capture and storage (CCS) leakage studies. The aim of this work was to investigate to what extend the high CO2 alone and in combination with the high temperature affects the microphytobenthic abundance and its community composition (Chapter 1). A further objective was to detect a possible change in the primary production rate in relation with these two variables. Higher microphytobenthic densities were recorded at the vent stations and values were even more pronounced in relation with high temperature. On the other hand, high microphytobenthic abundances were coupled with low community richness and diversity. The gross primary production estimates were strongly coupled with the microphytobentic abundance values. We observed several diatoms with morphological deformities,
The Port of Trieste represents an area with a diffuse sediment contamination as it is subjected to diverse impacts: the shipbuilding activities, the iron and steel plant, the petroleum industry and the port activities. The aim of this study (Chapter 2) was to detect any variation in the structure of the microbenthic community, both as active phototrophic and resting microbenthos, and the possible differences in the primary production and respiration at stations subjected to different anthropogenic impacts. The total microbenthic abundance did not vary among stations. On the other hand, the structure of the community gave more information. In particular, the analysis based on the active and resting microbenthic community structure highlighted a clear separation among stations close to the productive activities from the more distant ones and the reference station, indicating a contamination effect on those communities.
As an example of an area severely contaminated by heavy metals and synthetic organic compounds, the Mar Piccolo of Taranto was chosen. Firstly, the microphyto- and macrozoobenthic communities were investigated and a marked influence of contamination on the abundance and biodiversity of those two communities was detected (Chapter 3). To further asses the overall trophic status of the benthic ecosystem, an integrated study of the active phototrophic and resting microbenthic stages, combined with the main photoautotrophic pathways, was conducted (Chapter 4). Furthermore, although the Mar Piccolo is very shallow, the benthic system was scarcely productive, likely as a consequence of the accumulated contaminants in the surface sediments that probably interfere with the proper functioning of the benthic ecosystem. Contrary to the benthic ecosystem, the pelagic one was very productive and a clear seasonal succession of different sized plankton phototrophs was observed (Chapter 5). To have a better overall view and provide some insights into the benthic-pelagic coupling, the primary production and heterotrophic prokaryotic production in the water column were integrated with those in the sediments and related to the origin of the organic matter pools based on the analysis of stable isotopes (Chapter 6)
Can nuisance species profit from new materials for marine artificial structures? A pilot study on settlement of Chrysaora hysoscella on biochar-based concrete
No full textGrowing ocean-based human activities are causing the expansion of concrete structures in the marine environment, stressing the need for new solutions to minimize their ecological impact and carbon footprint. A promising approach in this perspective involves the use of biochar, a carbon-rich byproduct from thermochemical
treatment of waste biomass, as an additive to concrete. However, the introduction of novel substrata could pose unintended threats to marine ecosystems, including the potential diffusion of nuisance species. Here, through a set of laboratory experiments, we provided preliminary evidence on the effects of biochar addition to concrete on settlement and survival of the bloom-forming jellyfish Chrysaora hysoscella. The acute 24/48-h mortality test demonstrated a very low sensitivity of planulae to biochar. At both 7 and 14 days since the exposure to colonization of planula larvae, the number of settled polyps did not differ between concrete containing biochar (5–10 % wt.) and conventional concrete. Once settled, polyps exhibited comparable survival
regardless of the substratum. Our findings support the hypothesis that biochar-based concrete does not favor the invasiveness of this nuisance species with respect to conventional concrete, paving the way for future research on a wider range of (bio)char types and potentially harmful species, enabling broader implementations of these materials. The inherent advantages of biochar addition to concrete for marine uses, such as waste recycling and carbon storage potential, combined with its neutral effect on the spread of nuisance species, could represent a practicable and biocompatible solution to enhance the sustainability of marine artificial structures
Presenza di doglio, Tonna galea (Linnaeus, 1758) (Gastropoda: Tonnidae) in acque marine al largo della Slovenia (Adriatico settentrionale)
Full text linkOn 1st December 2018 a fisherman caught a specimen of the giant tun Tonna galea (Linnaeus, 1758) in the bottom trammel net for flounders, approximately 1 Nm outside the town of Izola. The net was placed on a muddy bottom at 20 m of depth. This is the second record of T. galea in the Slovenian waters (Gulf of Trieste, northern Adriatic Sea). Another specimen (the first one) was previously reported in October 2015 in the waters off Piran. By including T. galea in the checklist of Slovenian marine malacofauna, at least 370 gastropod species were up to date recorded in the Slovenian part of the Adriatic Sea.Il 1° dicembre 2018 un esemplare del gigantesco doglio Tonna galea (Linnaeus, 1758) è stato catturato con una rete da posta, il tramaglio, a circa 1 Nm dalla cittadina di Izola. La rete è stata posizionata su fondo fangoso a 20 m di profondità. Questo è il secondo ritrovamento di T. galea nelle acque slovene (Golfo di Trieste, Adriatico settentrionale). Un altro esemplare (il primo) è stato segnalato a ottobre 2015 nelle acque di Pirano. Includendo T. galea nella lista della malacofauna marina slovena, almeno 370 specie di gasteropodi sono state registrate nella parte slovena dell’Adriatico
Status invazivne tujerodne modre rakovice Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae) v Sloveniji
Full text linkAuthors present data regarding the presence of the invasive blue crab Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae) based on records gathered from local fishermen. This alien species was firstly recorded in Slovenian coastal waters in March 2019 and it was subsequently found in six other cases in 2019, 2020 and 2021. Crabs were collected or sighted in shallow coastal areas along the Slovenian coast. In addition, authors discussed about the status of the blue crab in marine and coastal habitats of Slovenia.Avtorja poročata o prisotnosti modre rakovice Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae) na podlagi podatkov, pridobljenih s strani lokalnih ribičev. Prvič smo to tujerodno vrsto v slovenskem obrežnem morju potrdili marca 2019, potem pa je bila zabeležena še v šestih primerih v letih 2019, 2020 in 2021. Rakovice so bile v vseh primerih ulovljene ali opažene v plitvem obalnem morju vzdolž slovenske obale. Avtorja nadalje razpravljata o statusu modre rakovice v obmorskih in morskih življenjskih okoljih v Sloveniji
Status invazivne tujerodne modre rakovice Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae) v Sloveniji
Full text linkAuthors present data regarding the presence of the invasive blue crab Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae) based on records gathered from local fishermen. This alien species was firstly recorded in Slovenian coastal waters in March 2019 and it was subsequently found in six other cases in 2019, 2020 and 2021. Crabs were collected or sighted in shallow coastal areas along the Slovenian coast. In addition, authors discussed about the status of the blue crab in marine and coastal habitats of SloveniaAvtorja poročata o prisotnosti modre rakovice Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae) na podlagi podatkov, pridobljenih s strani lokalnih ribičev. Prvič smo to tujerodno vrsto v slovenskem obrežnem morju potrdili marca 2019, potem pa je bila zabeležena še v šestih primerih v letih 2019, 2020 in 2021. Rakovice so bile v vseh primerih ulovljene ali opažene v plitvem obalnem morju vzdolž slovenske obale. Avtorja nadalje razpravljata o statusu modre rakovice v obmorskih in morskih življenjskih okoljih v Sloveniji
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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