Trophic interactions underlie coexistence mechanisms between species, define the functional role of specie within communities, affect biodiversity and bioaccumulation processes of heavy metal. Sea-ice dynamics, which at Terra Nova Bay is characterized by an extraordinary seasonality, drives interspecific interactions and the exchange of materials between ecosystem compartments. Indeed, the activation of the primary production after sea-ice break up opens alternative trophic pathways for consumers. The “next generation SRPs” represent a highly appropriate framework for the present project which follows the results obtained with the previous project ISOBIOTOX (PNRA 2013) and aims at (i) determine topological and functional metrics of sympagic and pelagic food webs at Terra Nova Bay under different conditions of sea-ice coverage along a distance gradient from the nearest open water polynya to areas were the seasonal sea-ice coverage persists longer; (ii) evaluate bioaccumulation and biomagnification of heavy metals in trophic sources at the base of the food web and in target species along food chains, including fishes of commercial interests and top predators, both in the presence and absence of sympagic and pelagic primary producers. High resolution food webs will be reconstructed by means of the simultaneous elemental and isotopic analysis of different elements (C and N) and the bioaccumulation of pollutants. The research program integrates complementary research approaches: (a) Elemental analysis coupled with mass spectrometry for stable isotope analysis (δ13C, δ15N) in animal and vegetal tissues and dead organic matter, (b)analyses of heavy metals accumulation (Chromatography) in the constituent species of the Antarctic food web.

The EMPHASIS project focuses on the ecomorphology of the feeding apparatus of Notothenioidea, a suborder of teleost fishes endemic to the Southern Ocean that have colonized available ecological niches and habitats during their adaptive radiation. Ecomorphology is the science that investigates the reciprocal relationship between the environment and the forms of organisms, allowing insights into their evolutionary history, biodiversity, and relationships between form and function. The research activity involves a comparative analysis of the feeding apparatus in species representative of various phyletic lineages, and the study of the relationships between morphology, function and specific performance during feeding. Based on the results of the analysis, three-dimensional digitally supported models of the structures involved in feeding activity was developed.

Trophic interactions underlie coexistence mechanisms between species and affect biodiversity and heavy metal bioaccumulation processes. Sea ice dynamics, which at Terra Nova Bay is characterized by an extraordinary seasonality, drives interspecific interactions. Indeed, the activation of the primary production after sea-ice break up opens alternative trophic pathways for consumers. By means of C and N stable isotope analyses, the present project aims at (i) determining food web structure at Terra Nova Bay at different bathymetries and in opposite sea-ice cover conditions; (ii) evaluating heavy metal bioaccumulation in species along food chains, including fish of commercial interests, both in the presence and absence of photosynthetic primary producers. The hypothesis to be tested is if the activation of primary producers following sea-ice break up significantly modifies the food web structure and stability against species loss, as well as heavy metals concentration along food chains. Data on Antarctic food webs are scarce, and even scarcer is our knowledge on mechanisms of primary and secondary biodiversity loss and biomagnification processes in invertebrates and fish. The present research project will shed light on mechanisms underlying biodiversity maintenance in the Antarctic ecosystem and on risks for human health related to heavy metals accumulation in fish species currently or potentially exploited commercially, also in light of expected changes in the extension of sea ice cover. A valuable reference baseline will be established for future studies at the Italian Antarctic Station and for the Marine Protected Area in the Ross Sea.

The raw SeaSpy magnetometer data presented here were collected in the Southern Ocean (SO) as part of the ISOBatA PNRA project during the XXXVII and XXXVIII Italian Antarctic expeditions on board the icebreaker Laura Bassi. The ISOBatA project (Italian Southern Ocean Bathymetry from consistent exploitation of opportunistic seafloor datasets in the Antarctic region and surrounding areas) aimed to improve the understanding of the Southern Ocean through a novel approach that systematically integrates the collection of bathymetric and magnetometric data during the Laura Bassi voyages in poorly charted regions between the Macquarie Triple Junction – MTJ and the Emerald Fracture Zone n-EFZ. This dataset spans two field campaigns (2021-2022 and 2023) collected through optimized navigation strategies, including reducing vessel speed during transits and following pre-planned corridors to enhance data quality and spatial coverage. The project was a collaboration between OGS (PI D. Accettella), UniMIB (A. Savini), IGAG-CNR (M. Cuffaro) and INGV (F. Muccini). The work was supported by the Programma Nazionale di Ricerca in Antartide - PNRA and benefited from the joint efforts of the Laura Bassi research teams on board. Keywords: Southern Ocean, Bathymetry, ISOBatA, Laura Bassi, Antarctica, IBCSO.

Isotopic composition (Pb and Sr) in particulate matter (PM10) samples, collected at Concordia with monthly time resolution, since January 2018, obtained by ICP-MS.

The effects of sea ice melting, and the consequent changes in the trophic conditions in Antarctic ecosystems, have been focused on phytoplankton with cross-food web links from krill to penguins, while the consequences on the planktonic microbial food web (viruses, prokaryotes and unicellular eukaryotes), driving biogeochemical cycles, have been largely ignored. This research investigates how changes related to sea ice melting influence the diversity and functioning of planktonic microbes in the Ross Sea coastal ecosystem of Terranova Bay. The objectives are: i) to investigate the temporal changes of planktonic microbial biodiversity, ii) to investigate the biodiversity/ecosystem functioning relationships iii) to assess the role of viruses on biodiversity and biogeochemical cycles, iv) to identify the drivers that shape microbial biodiversity and functions, and v) to shed light on the interactions within the planktonic food web, and their response to the ice melting. META-ICE-ROSS integrates ad hoc sampling with sophisticated methodologies of high-throughput sequencing of microbial DNA (metagenomics), never documented in previous Italian expeditions at Terranova Bay. The sampling includes the collection of seawater beneath the pack ice at increasing distance from the MZ Station and characterised by different thermohaline conditions, on a weekly basis from early November to mid January. The groundbreaking nature of META-ICE-ROSS will allow to provide unprecedented evidences on the role of microbial interactions in the functioning of the Ross Sea coastal ecosystem, to improve knowledge on biological changes due to global climate changes and, nonetheless, to provide a baseline assessment of the functioning of the microbial food webs and carbon sequestration in the pelagic environment in the Ross Sea region, within the context of the Ross Sea Region Marine Protected Area (RSRMPA) and its monitoring and research plan.

Anthropogenic microparticles (AMs) were found for the first time in specimens of Trematomus bernacchii collected in 1998 in the Ross Sea (Antarctica) and stored in the Antarctic Environmental Specimen Bank. Most of the identified AMs were fibers of natural and synthetic origin. The natural AMs were cellulosic, the synthetic ones were polyester, polypropylene, polypropylene/polyester, and cellulose acetate. The presence of dyes in the natural AMs indicates their anthropogenic origin. Five industrial dyes were identified by Raman spectroscopy with Indigo occurring in most of them (55%). Our research not only adds further data to the ongoing knowledge of pollution levels in the Antarctic ecosystem, it provides an interesting snapshot of the past, highlighting that microplastics and anthropogenic fiber pollution had already entered the Antarctic marine food web at the end of the ‘90 s. These findings therefore establish the foundations for understand the changes in marine litter pollution over time.

The data are related to the ionic composition of atmospheric aerosol continuously collected at Dome C. They refer to PM10 and size-segregated aerosol collected at 2-day and 4-day resolution, respectively. The measured chemical parameters include main and trace inorganic anions and cations and selected organic anions (methanesulphonic acid - MSA).

Below the results obtained by the HOT ANTARCTICA project are presented. Results regarding geochemistry of crustal melts Main results obtained by the most prominent samples are described separately for each of the investigated terranes (Napier Complex, Lützow Holm Complex, Rauer Islands and Schrimacher Hills). The methodology employed during the work is also listed below: 1) Samples interrogated in this project were previously collected from Napier Complex (provided by the collaboration with Prof. Simon Harley, University of Edinburgh), Lützow Holm Complex (provided by the collaboration with Prof. Satish-Kumar, University of Niigata), Rauer Islands (provided by the collaboration with Prof. Simon Harley, University of Edinburgh and in collaboration with Zhao Liu, Northwest University ,China) and Schrimacher Hills (provided by the Museo Nazionale dell’Antartide, Siena, Italy). 2) Microstructural and petrographic study were done in all samples to identify equilibrium assemblages, melting reaction microstructures and occurrence of nanogranitoids (i.e. crystallized inclusions), melt and fluid inclusions. 3) Microstructural characterization of inclusions using Field Emission-Scanning Electron Microscope (FE-SEM) analyses were done: i) to identify the submicrometric phases within nanogranitoids and ii) to verify the homogeneity of remelted nanogranites and preserved glassy melt inclusions. 4) Experimental remelting of crystallized melt inclusions was performed to overcome the problem of MI decrepitation and volatile loss. The remelting of nanogranitoids was performed at high pressure with a piston cylinder apparatus using a QUICKpress piston cylinder apparatus produced by Depths of the Earth (installed at the Dipartimento di Geoscienze, UniPd). 5) Analysis of the major and trace elements contents of melt inclusions was carried out using i) an electron microprobe at the at University of Milan and ii) a LAICPMS at University of Perugia. 6) Thermodynamic modeling of anatectic conditions: the evaluation of P-T-X parameters and of P-T paths in the different geologic contexts were carried out using the software Perple_X. 7) Micro-Raman spectroscopy: characterization of fluid inclusions coexisting with melt inclusions was done using a HORIBA LabRam HR (high resolution) Raman microspectrometer at the University of Pavia. 8) Cross-comparison of data: during the development of this research project all collected data were analyzed by cross-comparing the information from the different geological contexts, with the aim to highlight similarities and differences. 9) Data discussion and evaluation: all data was analyzed and discussed in tight collaboration with the researchers involved in this project. 10) Synthesis and dissemination of results: dissemination of results was done with oral and poster presentations in several international conferences (see list on the appropriate section - Atti). Presentations include invited keynote presentations by the PI, Bruna Borges Carvalho at Goldschmidt (France, 2023) and Hutton Symposium (Italy, 2023). Invited seminars were also given in several important universities around the world [University of Bern, Switzerland; University of Cambridge, UK; University of Niigata, University of Kyoto, Japan]. Furthermore, a total of two research papers have been published in journals of high impact factor, and other two articles are in preparation. Here we also provide mineral, geochemical and geochronological data of studied areas at Rundvagshetta and Rauer Islands. Preprinted versions of two published article where the data is explained are also provided. Carvalho, B.B., Bartoli, O., Cesare, B., Satish-Kumar, M., Petrelli, M., Kawakami, T., Hokada, T., Gilio, M. (2023). Revealing the link between A-type granites and hottest melts from residual metasedimentary crust. Geology 51, 845-849. https://doi.org/10.1130/G51097.1 Liu, Z., Carvalho, B.B., Li, W., Tong, L., Bartoli, O., Li, C., Chen, L., ,Yan, Q, Wu, H. 2023. Into the high to ultrahigh temperature melting of Earth’s crust: Investigations of melt and fluid inclusions within Mg–rich metapelitic granulites from the Mather Peninsula, East Antarctica. Journal of Petrology 64, egad051. https://doi.org/10.1093/petrology/egad051 Results regarding petrology and geochronology of granulites In northern Victoria Land, the presence of two contrasting P-T paths suggests the possibility that high-grade complexes could have experienced a different metamorphic evolution both in space and time. Geochronological data of the Granite Harbour Intrusives support a prolonged magmatic activity (540-480 Ma), with multiple igneous pulses. This could imply the existence of magmatic underplating triggering the development of monometamorphic granulites during the Ross Orogeny. On the other hand, structural and PT evolution suggest the presence of a polymetamorphic granulitic belt that could be remnant of older orogeny as the Panafrican (ca. 600-500 Ma) (Lombardo et al., 1987; Palmeri, 1997; Talarico and Castelli, 1995). In order to discriminate mono- from poly-metamorphic evolution, metasedimentary granulite complex from the Deep Freeze Range has been investigated. Among all available granulite samples, a detailed petrographical study has been conducted to select the most representative and suitable HT granulite-facies rocks: four samples have been individuated for petrological and geochronological analyses (Opx-Grt and >30 µm Zrn/Mnz bearing), fifteen for geochemistry (absence of leucosome). In the Deep Freeze Range, HT granulites consist of Grt-Opx±Bt±Crd±Spl±Crn gneisses characterized by the presence of numerous Opx±Grt leucocratic segregations. Geochemical results confirm that analyzed granulite protholites have sedimentary origin, being comparable to Post Archean Australian Shale (PAAS; Taylor and McLennan, 1985), and they have been deposited in an orogenic setting (active continental margin). Petrographical, microstructural and mineral chemistry analyses show a metamorphic evolution including three different stages: Pl-Grt1-Spl-Crn-Ilm medium-P granulite facies (M1), Qtz-Pl-Opx-Grt1-Crd-Ilm-Kfs low-P granulite facies (M2), and Qtz-Pl-Grt2-Kfs-Bt-Ath low-P amphibolite (M3). Preliminary petrological results indicate that evolving metamorphic parageneses describe an initial isothermal decompression (exhumation event) followed by isobaric cooling; further thermodynamic modeling by software Perple_X will allow to better define P-T-X conditions. Geochronological studies involved the observation and analysis of monazites and zircons on four selected granulite thin sections. Investigations included X-ray mapping carried out under the electron microscope, CL-BSE imaging (zircons), and trace element analysis and U-Pb dating using LA-ICP-MS. Acquired data are still under review and will have a fundamental role in the reconstruction of the P-T-t path, thus making it possible to discriminate between mono- and poly-metamorphic hypotheses. References Lombardo et al 1987. Memorie della Società Geologica Italiana 33, 99-130. Palmeri R. 1997. Lithos 42, 47-66. Talarico and Castelli D. 1995. Precamb. Res. 75, 157-174. Taylor and McLennan S.M. 1985. Blackwell, Oxford, 312 p.

The MBES NZ-water dataset was collected during the XXXIX PNRA Italian Antarctic Expedition aboard R/V Laura Bassi in direct response to a request from New Zealand to acquire bathymetric data during transits within their waters. The acquisition of this valuable dataset was carried out by the ISOBatA Project team, utilizing a state-of-the-art multibeam EM304 system installed on the R/V Laura Bassi. The genesis of the MBES NZ-water dataset is deeply linked to the international collaborative effort aimed at mapping unexplored regions, exemplified by the Seabed 2030 Project. By aligning with New Zealand's research objectives, both the ISOBatA project and the Italian Antarctic Expedition epitomize their commitment to knowledge exchange and the advancement of scientific understanding on a global scale.