Mozambique Channel 18S rDNA metabarcoding

Cold seeps are found globally in areas where gases escape from the seafloor, frequently resulting in the formation of topographic depressions known as pockmarks, which are characterised by unique physicochemical conditions, such as anoxic and sulphuric sediments. The processes defining community structure of free-living marine nematodes in areas of seepage, the most abundant meiofaunal taxon in such environments, remains largely unknown. Using a metabarcoding approach, we compared co-occurrence patterns and phylogenetic community structure of deep-sea nematodes in the Mozambique Channel between a low-activity pockmark, a reference area and abyssal sediments. We found that analysis at high and low taxonomic resolution offered a more complete description of the assemblage while our results highlight the influence of neutral dynamics in the pockmark, evidenced as randomness for these two measured qualities. The scarcity of information on community assembly of deep-sea assemblages, especially in the Mozambique Channel, renders our work a valuable contribution to the description of this little explored area as well as to our understanding of community ecology of idiosyncratic ecosystems such as pockmarks.