On the use of ROV for fish communities research and monitoring under sea ice at Terra Nova Bay (RSRMPA)

Shelf habitats represent under-sampled zones in the frame of research and monitoring programmes in the Ross Sea Region MPA. This “shadow-zone” extends on shelves at low to medium depths, from tens to few hundred meters, and is seasonally covered by sea ice. As part of the RESTORE project, under the Italian National Antarctic Research Program (PNRA), an Unmanned Underwater Vehicle (UUV) was used to survey shelf areas in Tethys Bay, close to the Italian Mario Zucchelli Station, during the late austral spring of 2022. PROTEUS (Portable RObot TEchnology for Underwater Surveys) was equipped with a selected sensory payload and was deployed from nine holes drilled in the sea ice at depths ranging from 13 to 183 m. The ROV collected a series of video footages close to the seafloor while also logging physico-chemical and geomorphological parameters. This study investigates the variation of fish communities along the path of the vehicle under fast ice. RESTORE created a unique dataset, providing insights into the presence and abundance of fish species associated with the benthic communities and, because abiotic data were geo-referenced and time-referenced, also with the variables collected by the sensors. This case study represents a reference point for non-invasive investigations of fish communities in remote protected areas.