TY  - JOUR
A1  - Lejzerowicz, Franck
A1  - Gooday, Andrew John
A1  - Angeles, Inés Barrenechea
A1  - Cordier, Tristan
A1  - Morard, Raphaël
A1  - Apothéloz-Perret-Gentil, Laure
A1  - Lins, Lidia
A1  - Menot, Lenaick
A1  - Brandt, Angelika
A1  - Levin, Lisa Ann
A1  - Martínez Arbizu, Pedro
A1  - Smith, Craig Randall
A1  - Pawlowski, Jan
T1  - Eukaryotic biodiversity and spatial patterns in the clarion-clipperton zone and other abyssal regions: insights from sediment DNA and RNA metabarcoding
T2  - Frontiers in Marine Science
N2  - The abyssal seafloor is a mosaic of highly diverse habitats that represent the least known marine ecosystems on Earth. Some regions enriched in natural resources, such as polymetallic nodules in the Clarion-Clipperton Zone (CCZ), attract much interest because of their huge commercial potential. Since nodule mining will be destructive, baseline data are necessary to measure its impact on benthic communities. Hence, we conducted an environmental DNA and RNA metabarcoding survey of CCZ biodiversity targeting microbial and meiofaunal eukaryotes that are the least known component of the deep-sea benthos. We analyzed two 18S rRNA gene regions targeting eukaryotes with a focus on Foraminifera (37F) and metazoans (V1V2), sequenced from 310 surface-sediment samples from the CCZ and other abyssal regions. Our results confirm huge unknown deep-sea biodiversity. Over 60% of benthic foraminiferal and almost a third of eukaryotic operational taxonomic units (OTUs) could not be assigned to a known taxon. Benthic Foraminifera are more common in CCZ samples than metazoans and dominated by clades that are only known from environmental surveys. The most striking results are the uniqueness of CCZ areas, both datasets being characterized by a high number of OTUs exclusive to the CCZ, as well as greater beta diversity compared to other abyssal regions. The alpha diversity in the CCZ is high and correlated with water depth and terrain complexity. Topography was important at a local scale, with communities at CCZ stations located in depressions more diverse and heterogeneous than those located on slopes. This could result from eDNA accumulation, justifying the interim use of eRNA for more accurate biomonitoring surveys. Our descriptions not only support previous findings and consolidate our general understanding of deep-sea ecosystems, but also provide a data resource inviting further taxon-specific and large-scale modeling studies. We foresee that metabarcoding will be useful for deep-sea biomonitoring efforts to consider the diversity of small taxa, but it must be validated based on ground truthing data or experimental studies.
KW  - deep-sea sediment
KW  - eukaryotic biodiversity
KW  - Foraminiferal
KW  - metazoans
KW  - 18S rRNA gene
KW  - bioinformatics
KW  - seafloor bathymetry
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62082
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-620826
SN  - 2296-7745
VL  - 8
IS  - art. 671033
SP  - 1
EP  - 23
PB  - Frontiers Media
CY  - Lausanne
ER  -