Spatial distribution of picoeukaryotic community from the hydrographic fronts of the indian sector of the southern ocean as revealed by metabarcoding

Marine picoeukaryotes constitute a vital component of pelagic communities and play a crucial role in recycling biogenic components, particularly in carbon cycling. Ongoing climate change in the Indian sector of the Southern Ocean (ISSO) may lead to significant variations in nutrient supply, potentially resulting in rearrangements in the community composition of picoeukaryotes. However, limited knowledge exists regarding their distribution in response to environmental heterogeneity. In this study, we sought to comprehend the composition of picoeukaryotic communities in the ISSO. During the austral summer of January–March 2020, eight sea surface samples were collected from diverse oceanographic frontal zones. We analyzed picoeukaryotes community composition using a metabarcoding approach through Illumina High-Throughput Sequencing (HTS) of the V9 region of the 18S rRNA gene. Multivariate analysis revealed discernible groupings among the samples, with each water mass characterized by its distinct physio-chemical features, dominant species, and community structure. This study, which examines the association between picoeukaryotes and environmental factors, underscores the potential application of picoeukaryotes as crucial bio-indicators.