Publication Date:
2024-02-02
Description:
Deep-sea sediments constitute a unique archive of ocean change, fueled by a permanent rain of mineral and organic remains from the surface ocean. Until now, paleo-ecological analyses of this archive have been mostly based on information from taxa leaving fossils. In theory, environmental DNA (eDNA) in the sediment has the potential to provide information on non-fossilized taxa, allowing more comprehensive interpretations of the fossil record. Yet, the process controlling the transport and deposition of eDNA onto the sediment and the extent to which it preserves the features of past oceanic biota remains unknown. Planktonic foraminifera are the ideal taxa to allow an assessment of the eDNA signal modification during deposition because their fossils are well preserved in the sediment and their morphological taxonomy is documented by DNA barcodes. Specifically, we re-analyze foraminiferal-specific metabarcodes from 31 deep-sea sediment samples, which were shown to contain a small fraction of sequences from planktonic foraminifera. We confirm that the largest portion of the metabarcode originates from benthic bottom-dwelling foraminifera, representing the in situ community, but a small portion (〈10 %) of the metabarcodes can be unambiguously assigned to planktonic taxa. These organisms live exclusively in the surface ocean and the recovered barcodes thus represent an allochthonous component deposited with the rain of organic remains from the surface ocean. We take advantage of the planktonic foraminifera portion of the metabarcodes to establish to what extent the structure of the surface ocean biota is preserved in sedimentary eDNA. We show that planktonic foraminifera DNA is preserved in a range of marine sediment types, the composition of the recovered eDNA metabarcode is replicable and that both the similarity structure and the diversity pattern are preserved. Our results suggest that sedimentary eDNA could preserve the ecological structure of the entire pelagic community, including non-fossilized taxa, thus opening new avenues for paleoceanographic and paleoecological studies.
Keywords:
ANT-XXIV/2; Arctic Ocean; ARK-XXII/2; AWI_Paleo; BC; Box corer; Center for Marine Environmental Sciences; Cruise/expedition; Date/Time of event; Davis Strait; Elevation of event; Event label; Galathea_3_Win3; Galathea_3_Win4; Galathea_3_Win6; Galathea 3; HDMS Vaedderen; KT07-14; KT07-14_MC03; KT07-14_MC04; KT07-14_MC07; Latitude of event; Longitude of event; Maria S. Merian; MARUM; MC03; MC04; MC07; MSM09/2; MSM09/2_432-5; MSM09/2_453-7; MSM09/2_472-2; MUC; MultiCorer; Name; Number of e-ribotype; Number of genotype; Number of morphospecies; Number of sequences; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS70/239-6; PS70/265-1; PS70/265-2; PS70/299-2; PS70/309-8; PS70 SPACE DAMOCLES; PS71/033-12; PS71/085-5; PS71/085-7; PS71 ANDEEP-SYSTCO SCACE; Reads; Reference/source; Sediment type; South Atlantic Ocean; Station label; Tansei Maru; Weddell Sea; Win 3; Win 4; Win 6
Type:
Dataset
Format:
text/tab-separated-values, 496 data points
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