Taxonomic comparison at the kingdom and phylum levels of eukaryotes detected with shotgun sequencing and metabarcoding. Credit: Gómez-Repollés et al., 2026 Researchers at Aarhus University have demonstrated that a simple adjustment to water filtration methods can dramatically improve the detection of marine animal DNA when using advanced, PCR-free sequencing. This methodological optimization could help clear a major bottleneck in aquatic biomonitoring and marine conservation efforts. The study is published in Metabarcoding and Metagenomics . PCR bias vs. bacterial overload Over the past two decades, environmental DNA (eDNA) analysis has become a crucial tool for monitoring aquatic ecosystems. The most common method, metabarcoding, relies on PCR amplification of a smaller genetic region to identify specific taxa. However, PCR can lead to "significant taxonomic bias" because it often amplifies the DNA of different organisms unequally, making quantitative estimates difficult.…