The amphipod assemblages of Sabellaria alveolata reefs from the NW coast of Portugal: An account of the present knowledge, new records, and some biogeographic considerations

Amphipod assemblages associated with the biogenic reefs built by the honeycomb worm Sabellaria alveolata were studied at two sites (Praia da Aguda and Belinho) along the northwestern coast of Portugal. A total of 3909 specimens were collected, comprising 14 different amphipod species. A first record from the northeastern Atlantic coast was registered here for the species Caprella santosrosai, which was, up to now, recorded only along the Mediterranean coast of the Iberian Peninsula. A male specimen collected from the Sabellaria-reef located in Belinho allowed an update to the known distribution of C. santosrosai, thus altering its previous status as an endemic Mediterranean species. The most common species collected during the study were Microdeutopus chelifer (n = 1828), Jassa ocia (n = 1426), and Hyale stebbingi (n = 452). Forty-three percent of the total recorded species were encountered in both study sites, whereas the remaining 57 % were restricted to a single site (Belinho). The majority of the collected species (93 %) showed an Atlantic-Mediterranean distribution, confirming the close affinity between eastern Atlantic and Mediterranean amphipod assemblages and the role of the Portuguese coast as a transition zone through which numerous warm-water species, coming from North Africa and the Mediterranean Sea, could enter into the Atlantic and possibly get mixed with species coming from the North Sea and the Arctic, typically having affinity for colder waters

Environmental representativity in marine protected area networks over large and partly unexplored seascapes

Converting assemblages of marine protected areas (MPAs) into functional MPA networks requires political will, multidisciplinary information, coordinated action and time. We developed a new framework to assist planning environmental representativity in a network across the marine space of Portugal, responding to a political commitment to protect 14% of its area by 2020. An aggregate conservation value was estimated for each of the 27 habitats identified, from intertidal waters to the deep sea. This value was based on expert-judgment scoring for environmental properties and features relevant for conservation, chosen to reflect the strategic objectives of the network, thus providing an objective link between conservation commitments and habitat representativity in space. Additionally, habitats' vulnerability to existing anthropogenic pressures and sensitivity to climate change were also scored. The area coverage of each habitat in Portugal and within existing MPAs (regionally and nationally) was assigned to a scale of five orders of magnitude (from 10%) to assess rarity and existing representation. Aggregate conservation value per habitat was negatively correlated with area coverage, positively correlated with vulnerability and was not correlated with sensitivity. The proposed framework offers a multi-dimensional support tool for MPA network development, in particular regarding the prioritization of new habitats to protect, when the goal is to achieve specific targets while ensuring representativity across large areas and complex habitat mosaics. It requires less information and computation effort in comparison to more quantitative approaches, while still providing an objective instrument to scrutinize progress on the implementation of politically set conservation targets.Agência financiadora Número do subsídio Oceanic Observatory of Madeira M1420-01-0145-FEDER-000001-OOM national funds through FCT UID/BIA/00329/2013 UID/Multi/04326/2013 Fundacao para a Ciencia e a Tecnologia SFRH/BPD/95334/2013 CESAM - FCT/MEC through national funds UID/AMB/50017 - POCI-01-0145-FEDER-007638 FEDER FCT SFRH/BPD/94320/2013 MARE - UID/MAR/04292/2019 EU through the Cohesion Fund POSEUR-03-2215-FC-000046 POSEUR-03-2215-FC-000047 FCT national funds ECO/28687/2017info:eu-repo/semantics/publishedVersio

Mediterranean bioconstructions along the Italian coast

Marine bioconstructions are biodiversity-rich, three-dimensional biogenic structures, regulating key ecological functions of benthic ecosystems worldwide. Tropical coral reefs are outstanding for their beauty, diversity and complexity, but analogous types of bioconstructions are also present in temperate seas. The main bioconstructions in the Mediterranean Sea are represented by coralligenous formations, vermetid reefs, deep-sea cold-water corals, Lithophyllum byssoides trottoirs, coral banks formed by the shallow-water corals Cladocora caespitosa or Astroides calycularis, and sabellariid or serpulid worm reefs. Bioconstructions change the morphological and chemicophysical features of primary substrates and create new habitats for a large variety of organisms, playing pivotal roles in ecosystem functioning. In spite of their importance, Mediterranean bioconstructions have not received the same attention that tropical coral reefs have, and the knowledge of their biology, ecology and distribution is still fragmentary. All existing data about the spatial distribution of Italian bioconstructions have been collected, together with information about their growth patterns, dynamics and connectivity. The degradation of these habitats as a consequence of anthropogenic pressures (pollution, organic enrichment, fishery, coastal development, direct physical disturbance), climate change and the spread of invasive species was also investigated. The study of bioconstructions requires a holistic approach leading to a better understanding of their ecology and the application of more insightful management and conservation measures at basin scale, within ecologically coherent units based on connectivity: the cells of ecosystem functioning

Valutazione dell'attivita antivirale di un pannello di farmaci nei confronti di SARS-CoV-2

SARS-CoV-2 è un virus a RNA a polarità positiva appartenente all’ordine Nidovirales e alla famiglia Coronaviridae. È stato isolato in Cina nel gennaio del 2020 e ha causato la pandemia da COVID-19. Si tratta di un virus ad alta patogenicità e trasmissibilità, per questo SARS-CoV-2 è classificato come agente patogeno con un livello di biosicurezza 3 (BSL-3), utilizzabile quindi solo in un laboratorio appositamente attrezzato. Per ovviare a questo problema e studiare la fase di ingresso del virus nella cellula è possibile ricorrere all’uso di vettori lentivirali pseudotipizzati (PLV), che possono essere manipolati anche in BSL-1 e BSL-2. Un PLV è una particella virale che possiede le proteine strutturali di un Lentivirus e la glicoproteina recettoriale S di SARS-CoV-2, avrà la struttura di un Lentivirus ma il tropismo di SARS-CoV-2 e si legherà quindi alla proteina hACE2. Il genoma di un PLV presenta alle estremità due sequenze long terminal repeat (LTR) ma non codifica più nessun gene di HIV, contiene solo una cassetta di espressione per un gene reporter, quindi non è in grado di replicarsi. Lo scopo della tesi è quello di valutare l’attività di un pannello di composti antivirali, sintetizzati dall’Università di Sassari, nei confronti dell’ingresso di SARS-CoV-2. Innanzitutto, è stato ottimizzato un protocollo per la produzione dei vettori pseudotipizzati con la proteina S di SARS-CoV-2 (PLV-S) o con la glicoproteina G del virus della stomatite vescicolare (PLV-VSV-G) da utilizzare come controllo positivo. Per migliorare l’efficienza di trasduzione da parte dei PLV-S sono state trasfettate stabilmente le cellule HEK-293T, con un plasmide codificante per il recettore di SARS-CoV-2, ACE2, ottenendo la linea cellulare HEK-293T/ACE2. Per validare il fatto che i PLV-S riproducessero il meccanismo di entrata del virus SARS-CoV-2, è stato fatto un test di neutralizzazione utilizzando campioni di siero provenienti da pazienti vaccinati contro COVID-19. A questo punto sono stati fatti saggi di citotossicità dei composti sulle cellule HEK-293T/ACE2 e dai risultati ottenuti sono state scelte 2 concentrazioni a cui effettuare il test di tutti i composti (5 µM e 0,5 µM). La valutazione dei composti è stata fatta utilizzando PLV-S con gene reporter luciferasi di lucciola in modo da valutare la loro efficacia tramite un luminometro in termini di unità di luce relativa (RLU). Tra tutti i composti ne sono stati scelti 6 che sembravano inibire l’ingresso dei PLV-S nelle cellule HEK-293T/ACE2 e sono stati ulteriormente testati a diverse concentrazioni (50, 10, 2, 0.4, 0.08 µM) per calcolare la concentrazione inibente il 50% dell’ingresso (IC50). Con i 2 composti più promettenti messi in evidenza da questo ultimo saggio, sono stati effettuati anche dei saggi di riduzione delle placche litiche con i virus CoxsackieB5 e VSV per capire se i composti fossero specifici per SARS-CoV-2 o fossero efficaci anche contro virus diversi. Infine, le cellule HuH7 sono state infettate con SARS-CoV-2 a due concentrazioni di farmaco (50 e 100 µM) e, per vedere l’effetto antivirale dei composti, è stato estratto l’RNA genomico dal surnatante delle cellule infettate per fare una qPCR, il substrato cellulare invece è stato lisato ed è stato effettuato un Western Blot per visualizzare le proteine virali. Come ultima esperimento, sempre con questi due composti, è stato effettuato un saggio del tempo di somministrazione, pre-trattando le cellule con il farmaco o somministrandoo dopo la trasduzione, per capire quale fosse il momento migliore per intervenire inibendo l’infezione

Measuring more of BETA-diversity: quantifying patterns of variation in assemblage heterogeneity. An insight from marine benthic assemblages.

Beta-Diversity is currently receiving increasing attention, after being neglected for a long time, especially in marine environments. Recent works introduced the distinction within Beta-diversity between turnover and variation. The former relates to directional changes in Beta-diversity along any gradient, the latter to nondirectional changes, or, in other words, to the heterogeneity of assemblages within any spatial, temporal, or environmental extent. However, the quantification of assemblage heterogeneity in assessing patterns of Beta-diversity is still largely unexplored. Here, we investigate the potential of classical and multivariate measures of Beta-diversity in highlighting patterns of assemblage heterogeneity examining eight cases of study from Mediterranean Sea, involving different marine organisms and a variety of environmental settings. Multivariate analyses were employed to assess differences in assemblage structure imputable to the investigated source of variability. ANOVAs on a set of diversity indices were also performed to test for effects on patterns of Alfa-diversity. Differences in assemblage heterogeneity were tested using both classical and distance-based multivariate dispersion measures of Beta-diversity as variation. Mean values of classical Beta-diversity metrics were analyzed using ANOVA, whereas, for distance-based multivariate dispersion, permutational tests based on a set of resemblance measures were carried out. In all study cases, analyses of Beta-diversity as variation showed significant effects of the investigated source of variability in modifying patterns of assemblage heterogeneity, even when no effects on the multivariate structure of assemblages and/or Alfa-diversity were detected. The assessment of Beta-diversity as variation could potentially unveil patterns of change in assemblages that could remain unnoticed analyzing other components of diversity, providing complementary information crucial to the understanding of the effects of natural and anthropogenic disturbances on natural assemblages

Taxonomic distinctness in Mediterranean marine nematodes and its relevance for environmental impact assessment

Taxonomic distinctness has been applied successfully for the exploration of biodiversity patterns, yet its relevance in environmental impact assessment is far from being unquestioned. In this study, we assessed the potential of taxonomic distinctness to discern perturbed and unperturbed sites by analysing Mediterranean nematode assemblages. Geographic and habitat-related effects on the performance of the index were also explored. Above all, our findings do not corroborate the conjecture that taxonomic distinctness could be largely unaffected by natural variability, habitat features, and biogeographic context, casting doubts on potential generalization concerning its application as an indicator of environmental stress. Taxonomic distinctness represents an excellent metric to identifying taxonomic properties of ecological systems but, as for other ecological indices, it should be viewed as a complementary tool in environmental impact assessment, due to its sensitiveness to specific environmental features of systems being investigated

Measuring more of \u3b2-diversity: Quantifying patterns of variation in assemblage heterogeneity. An insight from marine benthic assemblages

\u3b2-diversity is currently receiving increasing attention, after being neglected for a long time, especially in marine environments. Recent works introduced the distinction within \u3b2-diversity between turnover and variation. The former relates to directional changes in \u3b2-diversity along any gradient, the latter to non-directional changes, or, in other words, to the heterogeneity of assemblages within any spatial, temporal, or environmental extent. However, the quantification of assemblage heterogeneity in assessing patterns of \u3b2-diversity is still largely unexplored. Here, we investigate the potential of classical and multivariate measures of \u3b2-diversity in highlighting patterns of assemblage heterogeneity examining eight cases of study from Mediterranean Sea, involving different marine organisms and a variety of environmental settings. Multivariate analyses were employed to assess differences in assemblage structure imputable to the investigated source of variability. ANOVAs on a set of diversity indices were also performed to test for effects on patterns of \u3b1-diversity. Differences in assemblage heterogeneity were tested using both classical and distance-based multivariate dispersion measures of \u3b2-diversity as variation. Mean values of classical \u3b2-diversity metrics were analyzed using ANOVA, whereas, for distance-based multivariate dispersion, permutational tests based on a set of resemblance measures were carried out. In all study cases, analyses of \u3b2-diversity as variation showed significant effects of the investigated source of variability in modifying patterns of assemblage heterogeneity, even when the multivariate structure of assemblages and/or \u3b1-diversity were not affected. The assessment of \u3b2-diversity as variation can potentially unveil patterns of change in assemblages that could remain unnoticed analyzing other components of diversity, providing complementary information crucial to the understanding of the effects of natural and anthropogenic disturbances on natural assemblages

Human impacts on biogenic habitats: effects of experimental trampling on Sabellaria alveolata reefs

Human trampling is one of the main anthropogenic threats to coastal communities, especially in rocky intertidal habitats. The adverse effects of human trampling have recently received increasing attention from conservation biologists, especially when concerning species playing key functional roles. These include biogenic reefs providing extremely productive and diverse habitats due to their structural heterogeneity and three-dimensional complexity. The degradation of such habitats could not only adversely affect the whole coastal biota, but it could also have strong socio-economic implications. This study investigated the potential impact of human trampling on biogenic reefs built by the honeycomb worm Sabellaria alveolata in north-western Portugal. Three increasing intensities of human trampling were manipulated to test for their direct effects on S. alveolata bio-constructions and indirect effects on associated benthic infauna. Experimental trampling, even at low intensity, negatively affected reefs by reducing the percentage cover of intact S. alveolata concretions over a period of two months, but it did not alter the structure of whole assemblages compared to the unmanipulated condition. Idiosyncratic responses were shown by the most conspicuous taxa, ranging from no significant effects on S. alveolata and Amphipoda to spatially and temporally variable effects on the Syllidae and Sabellidae polychaetes, the Mytilidae bivalves and the Rissoidae gastropods. When present, however, differences were always in the direction of larger abundances under the highest intensity of trampling than in the less disturbed treatments and the unmanipulated control. This study provides one of the first experimental evidence linking the intensity of human trampling to the physical damage of S. alveolata reefs. Direct implications of present findings as tools to promote a sustainable use of these systems at a local scale and to stimulate protection and management initiatives at other locations are discussed