Maximising signal-to-noise ratios in environmental DNA-based monitoring

Understanding and minimizing impacts arising from human activities requires cost-effective monitoring. eDNA-metabarcoding based approaches offer considerable potential for reducing monitoring costs but only where the signal (source of change) to noise ratio is sufficiently high. On an organic-enrichment gradient (source of change), we showed that the 16S eDNA marker demonstrated the highest signal: noise ratio, followed by the 18S then COI markers, when based on unannotated sequences.