Offshore Scotian Shelf biodiversity assessment using eDNA metabarcoding 2025

Samples were collected in summer 2025 (July and August) as part of the annual DFO multispecies trawl survey, and in October 2025 as part of the annual Atlantic Zone Monitoring Program. Seawater samples were collected from near bottom using a CTD rosette and filtered aboard the research vessel using a Smith Root vacuum pump and 1.2 um filters. eDNA was extracted from the filters and sequenced on an Illumina MiSeq platform at the Aquatic Biotechnology Laboratory based at the Bedford Institute of Oceanography.

Raw sequence reads were demultiplexed and denoised using DADA2 in the QIIME2 pipeline, and taxonomy was assigned to amplicon sequence variants using BLASTn and the NCBI eukaryote nucleotide database.