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Environmental diagnostics are commonly used to identify anthropogenic influences in various environmental settings. However, the use of a single survey technique is limiting and leads to an incomplete and often inaccurate picture of reality. In this study, three real cases analyzing impacts on marine ecosystems have been presented to prove how the integration of different diagnostic techniques can be very beneficial to better understand the phenomena that occur as well as the impacts and associated damages. Studies combining classical diagnostics based on the determination of contaminant levels by chemical analysis, ecotoxicological tests and stress biomarkers with diagnostics by Field Emission Scanning Electron Microscopy-FESEM and X-ray diffraction-XRD microscopy are reported. Findings suggest that the embedding of chemical analyses, ecotoxicology and microchemical FESEM and XRD analyses allow us to hit the mark and give precise and effective responses in environmental management.

In open regions of the Ross Sea, the role of the microbial community in the turnover of organic matter has scarcely been investigated; indeed, very little is known on how microbial distribution and functional diversity respond to environmental conditions and hydrographic structures. During the austral summer of 2017, two pelagic areas of the Ross Sea [the Drygalski Ice Tongue and the nearby Terra Nova Bay polynya (A area), and the continental Shelf Break area near Cape Adare (C area)] were studied at selected depths [surface, Deep Chlorophyll Maximum (DCM), Circumpolar Deep Water (CDW), deep waters]. Trophic properties [nutrient concentrations, particulate (POC), dissolved organic carbon (DOC) and its optically significant fraction (CDOM) were measured, together with the main hydrological variables. Microbial community abundance [total prokaryotes, living, dead, and actively respiring fraction, high- and low nucleic acid cells (HNA and LNA), pico- and nano-eukaryotes, culturable heterotrophic bacteria], composition, and metabolism (as whole community and as isolated bacteria) were also assessed. Through a multidisciplinary dataset, this study highlighted the variable response of microbial abundance, diversity, and metabolism of the microbial community to the changing local environmental conditions of the Ross Sea. Different forces, such as organic matter inputs (mostly of detrital nature) released from the Drygalski glacier in the A area, and a coastal-to-offshore gradient in the C area, coexisted within this extreme ecosystem. This resulted in a significant spatial segregation of the edaphic parameters, and of the microbial community distribution and metabolic activity patterns.