Multidisciplinary study of enigmatic mounds in the East Antarctica offshore (MYSTERO)

The MYSTERO project originates from a scientific collaboration between the Institute of Marine Sciences of the National Research Council (CNR-ISMAR), the National Institute of Oceanography and Applied Geophysics (OGS), the Anton Dohrn Zoological Station (SZN), and the University of Naples Federico II.
The project arises from the observation of numerous sub-circular submarine reliefs, tens of metres high and hundreds of metres wide, distributed along the continental shelf, continental margin, and abyssal plain of the western Ross Sea, offshore Cape Adare, at depths between 300 and 1200 metres. Although these “mounds” are relatively common in the area, their origin and environmental role remain poorly understood.
The aim of MYSTERO is to investigate the genesis, formation mechanisms, and environmental conditions associated with these features through a multidisciplinary approach. During the XLI Antarctic expedition of the R/V Laura Bassi (January–February 2026), geophysical and geomorphological surveys, sediment sampling, analyses of near- bottom water masses, and biological investigations were conducted to characterise benthic communities, including corals and other organisms colonising these environments, as well as microbial communities. This was the first of two Antarctic expeditions aboard the OGS icebreaker; during the 2026/27 season, in addition to completing the acquisition of geophysical and geological data, the use of an ROV (operated by the SZN) is planned to acquire imagery of the seafloor.
Particular attention is given to the interactions between these reliefs and the main water masses influencing the area, such as Circumpolar Deep Water (CDW) and Ross Sea Bottom Water (RSBW), in relation to processes of water warming, seabed ventilation, nutrient supply, and sea-ice-related dynamics. The sediments associated with the mounds also represent a valuable natural archive for paleoclimatic and paleoceanographic reconstructions, contributing to the understanding of Antarctic ice-sheet evolution and gas and fluid migration processes.