• Energy Research

This study is based on assessing fecal indicator bacteria contamination along meteorological, hydrological and physical-chemical variables after high rainy events during the summer period. The study focused on four different coastal sites in the western and eastern Adriatic coast characterized by various geomorphological and hydrological features, levels of urbanization and anthropogenic pressures, with the aim of finding appropriate and effective solutions to ensure the safety and sustainability of tourism and public health. Detailed in-situ survey revealed a wide range of fecal indicator bacterial (FIB) across the different river mouths with concentrations of E. coli ranging from 165 to 6700 CFU 100 mL-1. It was found that nitrogen compounds track microbial load and acted as tracers for fecal contaminants. Further, a modelling tool was also used to analyze the spatial and temporal distribution of fecal pollution at these coastal sites. The integrated monitoring through high frequent survey in river waters and modeling framework allowed for the estimation of fecal indicator bacterial load at the river mouth and examination of fecal pollutant dispersion in recreational waters, considering different scenarios of fecal dispersion along the coast. This study formed the basis of a robust decision support system aimed at improving the management of recreational areas and ensuring the protection of water bodies through efficient management of bathing areas.

Arctic regions are among the fastest warming areas of the planet. Increasing average temperatures over the last five decades have deepened the thawing of the upper-most layer of permafrost across the Arctic, which contains significant amounts of organic carbon. The progressive deepening of seasonal thawing releases carbon that is used by active microorganisms which also produce greenhouse gases, potentially onsetting a positive feedback on global warming. Despite their importance in controlling organic matter degradation and greenhouse gas fluxes to the atmosphere, there is a lack of data on activity and dynamics of microbial communities in High Arctic soils in response to seasonal thaw. This report describes three specific expeditions performed on the Svalbard archipelago, carried out within the framework of the PRA (Italian Arctic Research Program) project Melting-ICE, performed between February and October 2022, reporting site characteristics and samples collected. The project aims to investigate the diversity and activity of active layer microbial communities across a full season thaw cycle, correlating microbial diversity with gas fluxes and composition. During these expeditions, a total of eight different sites were selected to investigate the microbiology and geochemistry of soils, as well as to estimate the gas fluxes from the soil to the atmosphere. The data collected in the field, combined with the results obtained in the laboratory, will provide a snapshot of the seasonal activity of the microbial communities present in the permafrost’s active layer. The three campaigns will provide data to estimate the impact of permafrost melting on the carbon cycle and the role of microorganisms in the release of greenhouse gases.

A comparative study for abundance, biomass and diversity was carried out for the prokaryote, meiofauna and macrofauna communities at three depth stations (1200, 1800 and 2100 m) along the Malta Escarpment (Mediterranean Sea). Our investigation showed a two-fold increase with depth in prokaryote abundance; the contribution of prokaryote biomass to the total benthic biomass was predominant at all depths. Bacteria were the dominant prokaryote component and Archaea formed a considerable fraction (20%-30%) of the prokaryote assemblages. The meio- and macrofauna abundances and meiofauna biomass did not decrease significantly with depth but macrofauna biomass did. The α diversity did not follow a clear bathymetric trend for both nematode and macrofauna species. Probably because of the large number of eurybathic nematode genera, nor did the turnover diversity in nematode composition change down the depth gradient. Conversely, for the macrofauna there was a perceptible change in community composition between the shallowest station and the two deeper stations. Food availability affected only the macrobenthic component. The increase in the prokaryote organisms with depth and the dominance of nematodes and macrofauna deposit feeders suggest active grazing by the two benthic components on microbes. This would transfer energy to the higher trophic levels through the microbial compartment.

The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can be seen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project ("Biodiversity and Ecosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna"), we investigated the large spatial scale variability (over >1,000 km) of the bathyal macrofauna communities that inhabit the Mediterranean basin, and their relationships with the environmental variables. The macrofauna abundance, biomass, community structure and functional diversity were analysed and the α-diversity and β-diversity were estimated across six selected slope areas at different longitudes and along three main depths. The macrobenthic standing stock and α-diversity were lower in the deep-sea sediments of the eastern Mediterranean basin, compared to the western and central basins. The macrofaunal standing stock and diversity decreased significantly from the upper bathyal to the lower bathyal slope stations. The major changes in the community composition of the higher taxa and in the trophic (functional) structure occurred at different longitudes, rather than at increasing water depth. For the β-diversity, very high dissimilarities emerged at all levels: (i) between basins; (ii) between slopes within the same basin; and (iii) between stations at different depths; this therefore demonstrates the high macrofaunal diversity of the Mediterranean basins at large spatial scales. Overall, the food sources (i.e., quantity and quality) that characterised the west, central and eastern Mediterranean basins, as well as sediment grain size, appear to influence the macrobenthic standing stock and the biodiversity along the different slope areas.

The transfer of communication and knowledge from science and research to the general public is a paramount step to raise people’s awareness about environmental issues and their negative and positive impacts on each of us. Many projects and initiatives seek to raise awareness among citizens, with particular attention to young people, about the importance of maintaining clean and healthy oceans. With this paper, we aim to present the successful communication initiatives developed during two Interreg projects, AdSWiM and WATERCARE, with schools and educational organisations on the local and national levels in Italy and Croatia. Both projects make a special effort to realize dedicated communication strategies with the objective of raising the awareness of environmental topics and issues among young people (i.e., students of different school grades) and teachers. The promotion of ocean literacy among students is crucial, as children and young people represent the future citizens and consumers who will develop attitudes and make decisions that will inevitably affect the environment.

Estuarine waters are known to enhance productivity in coastal environments, but little is known about the impact that nutrient-rich waters can have on benthic microbial processes. After intensive surface sediment sampling in a wide coastal area impacted by river plume waters, we performed on-site microcosm experiments in which we added estuarine waters, rich in both organic and inorganic N and P, to pristine offshore sediments. This experimental approach has been conducted in different coastal areas for two consecutive years, in which the river-plume waters differed in both inorganic and organic N and P content. Benthic bacterial response (total bacterial abundance and biomass, aminopeptidase, beta-d-glucosidase and bacterial C production) was investigated in treated and non-treated sediments. All structural and functional microbial variables increased significantly after plume-water supply (within 12-24 h bacterial abundance in the sediment doubled and enzymatic activities increased up to >50%). Results indicate that inorganic N supply from plume waters was sufficient to induce a significant response in benthic bacterial abundance, independently from the presence of high and/or variable N:P ratios. However, bacterial carbon production and exo-enzymatic activities increased significantly when the supply of organic P from plume waters was associated with a decrease of organic N:P ratios. We conclude that plume waters have important effects on benthic bacterial dynamics, but the extent of their biogeochemical implications is largely dependent upon their organic P availability and on stoichiometric ratios of organic nutrients supplied by plume waters.