Guidelines for using environmental DNA in Finnish marine phytoplankton monitoring – Improved biodiversity assessment through method complementation. GeMeKa

This document is a methodological guide for using a genomic ecosystem survey technique (eDNA metabarcoding) to supplement conventional phytoplankton monitoring of the Finnish marine monitoring program. The guidelines describe the detection of eukaryotic and prokaryotic phytoplankton with 18S and 16S rDNA gene primers, using high-throughput sequencing. The document includes information on sampling, sample processing, molecular biological work, quality control, and bioinformatics so that the method can be applied in addition to standardized light microscopy. The guidelines are based on a first pilot project testing the integration of eDNA metabarcoding in Finnish marine phytoplankton monitoring and will be developed further, according to evolving genetic methods and international guidelines and standards. Suggestions on steps towards introducing eDNA methodology in phytoplankton monitoring are included in the guidelines. Using eDNA metabarcoding to complement standardized light microscopy advances conventional monitoring and research of phytoplankton communities to assess biodiversity and the status of the marine environment.