Assessment of an abyssal near-bottom zooplankton community via metabarcoding

Near-bottom abyssal zooplankton was collected with plankton pumps (63-μm) in the eastern Clarion Clipperton Fracture Zone (CCZ - 4,100 m depth), and samples were split for molecular and morphological analyses. Amplicons from the 18S rRNA and mtCOI gene were sequenced on the Illumina MiSeq platform to determine species richness, diversity, and spatial variability of the bentho-pelagic zooplankton assemblage in the abyssal tropical North Pacific. Results from paired molecular and morphological taxonomic analyses of quantitative sample splits were compared and differences between them evaluated. The characterisation of the abyssal ecosystem of the CCZ will provide valuable baseline data in advance of anticipated mining of the mineral-rich polymetallic nodules. The approach used here will provide an efficient model for the comprehensive assessment of the bentho-pelagic zooplankton community in this ecosystem.