Multi-marker metabarcoding approach to study mesozooplankton at basin scale

Zooplankton plays a pivotal role in marine ecosystems and the characterisation of its biodiversity still represents a challenge for marine ecologists. In this study, mesozooplankton composition from 46 samples collected in summer along the western Adriatic Sea, was retrieved by DNA metabarcoding analysis. For the first time, the highly variable fragments of the mtDNA COI and the V9 region of 18S rRNA genes were used in a combined matrix to compile an inventory of mesozooplankton at basin scale. The number of sequences retrieved after quality filtering were 824,148 and 223,273 for COI and 18S (V9), respectively. The taxonomical assignment against reference sequences, using 95% (for COI) and 97% (for 18S) similarity thresholds, recovered 234 taxa. NMDS plots and cluster analysis divided coastal from offshore samples and the most representative species of these clusters were distributed according to the dominant surface current pattern of the Adriatic for the summer period. For selected sampling sites, mesozooplankton species were also identified under a stereo microscope providing insights on the strength and weakness of the two approaches. In addition, DNA metabarcoding was shown to be helpful for the monitoring of non-indigenous marine metazoans and spawning areas of commercial fish species. We defined pros and cons of applying this approach at basin scale and the benefits of combining the datasets from two genetic markers

Distribution of Engraulis encrasicolus eggs and larvae in relation to coastal oceanographic conditions (the South-western Adriatic Sea case study)

Identification of potential spawning and nursery areas of European anchovy (Engraulis encrasicolus) represents an essential step in the management of a resource which is of fundamental importance both for fishery and pelagic trophic web. Egg and larvae occurrence from ichthyoplankton surveys (2012 - 2015) in the South Western Adriatic Sea were examined to understand the mechanisms that control their distribution. Egg and larvae densities varied through the years with the highest values recorded in 2012 and the lowest in 2014. Positive correlations between eggs and larvae with zooplankton were observed. When quotient analysis was used to find relations with environmental and biological variables, the results pointed out an egg preference for depth between 91 and 120 m and an avoidance between 11 and 30 m. Moreover, egg avoidances for high values of chlorophyll-a (> 0.52 mg m-3) and low values of zooplankton biomass ( 151 m; preference for high zooplankton biomass (> 1000 mg m-2) and avoidance for low biomass (< 299 mg m-2). These correlations and the quotient values suggest that egg and larvae distribution in the South-Western Adriatic Sea is mainly driven by food availability and depth

“New records of rare species in the Mediterranean Sea” (October 2021)

“New records of rare species in the Mediterranean Sea” (October 2021

Feeding habits of European pilchard late larvae in a nursery area in the Adriatic Sea

10 pages, 5 figures, 3 tables, 1 appendixEuropean pilchard Sardina pilchardus late larvae were collected in the Gulf of Manfredonia, an important nursery area, during their seasonal inshore occurrence. Thanks to diel cycle sampling and to the wide range of larval lengths (from a minimum of 27 mm to a maximum of 45 mm), both feeding rhythm and ontogenetic changes were analysed. The feeding peak was observed in the afternoon, before sunset. Sardine larvae were exclusively zooplanktivorous, their diet being based on Calanoid Copepods from the genus Paracalanus (IRI% = 65.7), on the species Temora longicornis (IRI% = 15.5) and other small-sized Copepods. Other planktonic organisms appeared in the stomach contents occasionally and never reached IRI% values > 1. The number of prey per stomach increased suddenly at larval lengths around 40 mm, corresponding to the development of the stomach. Prey composition in the environment was established by contemporaneous sampling of plankton, performed by means of two plankton nets with different meshes. The main prey items were positively selected among those available in the field, but some other prey (Centropages spp., Harpacticoids, Corycaeids, Temora stylifera and Acartia spp.) were also preferred, although rare in the plankton samples. In contrast, copepod nauplii, despite their abundance in the environment (15,848 ± 4441 individuals m− 3), were only occasionally recovered in the larval gut contents (N = 0.26%). This shows that sardine late larvae have switched to larger prey itemsThe present studywas financially supported by the European Project SARDONE (Improving assessment and management of small pelagic species in the Mediterranean, FP6-44294)Peer Reviewe

Un Robot, affascinato, dipinge il mare

Introduce e modera Maria Campitelli, presidente associazione culturale Gruppo 78 Intervengono Paolo Gallina, docente di Meccanica applicata Università di Trieste Diego Borme, ricercatore Sezione di oceanografia, OGS Eric Medvet, docente di Machine Learning and Data Mining Università di Trieste A cura di Università di Trieste, in collaborazione con Università di Udine Può un qualcosa di meccanico produrre arte? Nella fattispecie, può un robot, dotato magari di intelligenza artificiale, produrre qualcosa che abbia una valenza artistica? Queste e altre domande sono lecite dato che viviamo in un’epoca nella quale l’automazione e le tecnologie digitali sono entrate così pervasivamente nella nostra vita da renderci uomini e donne diversi rispetto a dieci o vent’anni fa. In questa conferenza si parlerà proprio di questo: il connubio tra arte e robotica (compresa anche l’intelligenza artificiale). Lo si farà partendo da esempi pratici, lontani e vicini, precursori di riflessioni che coinvolgono la definizione stessa di arte. E lo si farà anche presentando punti ti vista all’apparenza antitetici. Nondimeno, verranno mostrati i risultati di un gruppo composto da artisti e ingegneri teso a creare suggestioni estetiche attraverso la programmazione di un “robot pittore”. Maria Campitelli curatrice di arte contemporanea, è presidente del Gruppo 78 associazione culturale di Trieste con cui ha realizzato oltre 500 eventi, incentrati sulla media-art, sul connubio arte/scienza. Cura scambi culturali con altri paesi, in particolare con il Messico e con la Svizzera. Nell’ambito del rapporto arte/scienza ha prodotto la mostra internazionale “Aurelia 1+Hz, Arte/Scienza/Biotecnologia” (2015), ora in Messico, “Arte/Scienza/La Robotica” (2016); ha in preparazione “Robotics2. Il Gruppo78, associazione culturale attestata sull’arte contemporanea, da qualche tempo si orienta sul rapporto arte/scienza/tecnologia, puntando, dal 2016, sulla specificità della robotica. Il legame arte/scienza si attua in vari modi, adottando i linguaggi tecnologici, al posto di quelli tradizionali, o inducendo il robot a produrre pittura, disegno. Attraverso una serie di video (di Flego, Rinaldo, Cocho, Kiessling) si proporranno delle ricerche dove arte e tecno-scienza tendono a fondersi. Paolo Gallina è Professore associato di Meccanica Applicata alle Macchine. È Coordinatore del corso di Ingegneria industriale. I suoi campi di ricerca riguardano le vibrazioni, le interfacce uomo macchina e la robotica. È autore del romanzo/saggio "La formula matematica della felicità", 2012, Mondadori Ed. e del saggio scientifico “L’anima delle Macchine”, 2015, Dedalo Ed., col quale ha vinto il premio Internazionale Galileo. Twitter @paolo_gallina Eric Medvet è ricercatore universitario presso il DIA dell’Università degli Studi di Trieste e professore aggregato di Machine Learning e Data Mining. È responsabile del Machine Learning Lab, che svolge attività di ricerca nei campi dell’apprendimento automatico e del calcolo evoluzionistico in collaborazione con aziende nazionali ed università e centri di ricerca internazionali. Twitter @EricMedvetT

Diet of Adult Sardine <i>Sardina pilchardus</i> in the Gulf of Trieste, Northern Adriatic Sea

Food availability is thought to exert a bottom-up control on the population dynamics of small pelagic fish; therefore, studies on trophic ecology are essential to improve their management. Sardina pilchardus is one of the most important commercial species in the Adriatic Sea, yet there is little information on its diet in this area. Adult sardines were caught in the Gulf of Trieste (northern Adriatic) from spring 2006 to winter 2007. Experimental catches conducted over 24-h cycles in May, June and July showed that the sardines foraged mainly in the late afternoon. A total of 96 adult sardines were analysed: the number of prey varied from a minimum of 305 to a maximum of 3318 prey/stomach, with an overall mean of 1259 ± 884 prey/stomach. Prey items were identified to the lowest possible taxonomical level, counted and measured at the stereo-microscope. Overall, sardines fed on a wide range of planktonic organisms (87 prey items from 17 μm to 18.4 mm were identified), with copepods being the most abundant prey (56%) and phytoplankton never exceeding 10% of the prey. Copepods of the Clauso-Paracalanidae group and of the genus Oncaea were by far the most important prey. The carbon content of prey items was indirectly estimated from prey dry mass or body volume. Almost all carbon uptake relied on a few groups of zooplankton. Ivlev’s selectivity index showed that sardines positively selected small preys (small copepods < 1 mm size), but also larger preys (such as teleost eggs, decapod larvae and chaetognaths), confirming their adaptive feeding capacity

Diet of Adult Sardine Sardina pilchardus in the Gulf of Trieste, Northern Adriatic Sea

Food availability is thought to exert a bottom-up control on the population dynamics of small pelagic fish; therefore, studies on trophic ecology are essential to improve their management. Sardina pilchardus is one of the most important commercial species in the Adriatic Sea, yet there is little information on its diet in this area. Adult sardines were caught in the Gulf of Trieste (northern Adriatic) from spring 2006 to winter 2007. Experimental catches conducted over 24-h cycles in May, June and July showed that the sardines foraged mainly in the late afternoon. A total of 96 adult sardines were analysed: the number of prey varied from a minimum of 305 to a maximum of 3318 prey/stomach, with an overall mean of 1259 &plusmn; 884 prey/stomach. Prey items were identified to the lowest possible taxonomical level, counted and measured at the stereo-microscope. Overall, sardines fed on a wide range of planktonic organisms (87 prey items from 17 &mu;m to 18.4 mm were identified), with copepods being the most abundant prey (56%) and phytoplankton never exceeding 10% of the prey. Copepods of the Clauso-Paracalanidae group and of the genus Oncaea were by far the most important prey. The carbon content of prey items was indirectly estimated from prey dry mass or body volume. Almost all carbon uptake relied on a few groups of zooplankton. Ivlev&rsquo;s selectivity index showed that sardines positively selected small preys (small copepods &lt; 1 mm size), but also larger preys (such as teleost eggs, decapod larvae and chaetognaths), confirming their adaptive feeding capacity

Alimentazione e salute con i prodotti del nostro mare

Intervengono Gianni Biolo, docente di Medicina interna Università di Trieste Diego Borme, ricercatore Sezione di oceanografia, OGS Paola Del Negro, direttrice Sezione di oceanografia, OGS Michele Zanetti, docente di Medicina interna, Università di Trieste A cura di Istituto nazionale di oceanografia e di geofisica sperimentale – OGS e Università di Triest