Preliminary results of sediments eDNA metabarcoding along arctic fjord

• Published in: ARPHA Conference Abstracts
• Main Authors: Mazurkiewicz, Mikołaj, Pawłowska, Joanna, Pawlowski, Jan, Włodarska-Kowalczuk, Maria
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Pensoft Publishers 2021
• Subjects: eDNA; Arctic; benthos; 18S; COI; glacier; Hornsund; Svalbard
• Online Access: https://doi.org/10.3897/aca.4.e64935

Ecosystems of arctic fjords are exposed to various natural and human-induced stressors that shape the taxonomic structure and functioning. Glacial activity and meltwater inflows together with advection of sea water masses from shelves form variety of environmental gradients that have been shown to influence marine biota. Some of these stressors like sedimentation of inorganic matter, instabilities of bottom sediments or food supply have been recognized as drivers of benthic species richness and diversity with use of traditional (morphology based) methods (Węsławski et al. 2011, Włodarska-Kowalczuk et al. 2005, Włodarska-Kowalczuk et al. 2012). In this study we aimed to use eDNA metabarcoding based methods to discriminate ecological diversity of benthic Eukaryota along environmental gradient (fjord mouth – glacier) at 6 stations in Hornsund fjord (Svalbard). At each station we collected 9 surface sediment samples. To cover a wide diversity of eukaryotic taxa we sequenced mitochondrial COI and nuclear 18S VIV2 genes to. Computational pipeline (SLIM, Dufresne et al. 2019) was used to de-multiplexed sequences, cluster them into ASVs and then taxonomically assigned. For the COI marker we distinguished 4486 unique ASVs, which in majority (95%) remained unassigned but constituted 51% of all sequences. Among sequences with assigned taxonomy 98% of them belonged to Opisthokonta clade, which consisted of 12 phyla in majority Annelida (80% of seqences) followed by Nemertea (13%) and Echinodermata (6%). In case of 18S marker we obtained 1309 unique ASVs, almost 70% of them were taxonomically assigned, constituting almost 97% of all sequences. Seven clades were assessed with dominance of Opistokonta (44%) followed by Stramenopiles (29%) and Rhizaria (18%) of all sequences. Among Opistokonta we noted 17 phyla, which were dominated by Annelida (54% of sequences) with significant share of Arthropoda (20%), Nematoda (10%) and Nemertea (8%). Analysis of alpha diversity expressed as number of unique ASV and Shannon-Wiener index ...