Pelagic ecosystem monitoring of the key species of Middle Trophic Level in the Ross Sea Marine Protected Area

The Middle Trophic Level of the Ross Sea is still not well known but it mainly characterized by two species of Krill: Euphausia superba, Euphausia Crystallorophias. These species are a key food source for a wide variety of marine birds and mammals in the Ross Sea. For this reason, it's necessary to improve the knowledge on abundance and spatial distribution of MTL species, and their interconnection with environmental parameters to understand the main drivers of the reproductive success and migrations of these species. In this project, an acoustic survey, a synoptic net sampling and a CTD/XBT samplings were carried out following the standard protocols indicated by CCAMLR. Acoustic monitoring was performed at five frequencies: 38, 70, 120, 200 and 333 kHz. Targeted net samplings were performed to validate the preliminary species allocation of the aggregations observed on the echosounder screen. Biometric measures of krill samples was made on board and samples were taken for further analysis. CTD and XBT data was collected and elaborated to characterize water masses and to study the possible influences of the distribution of the main oceanographic parameters on MTL species.