Assessing the relevance of DNA metabarcoding compared to morphological identification for lake phytoplankton monitoring.

Phytoplankton is a key biological group used to assess the ecological status of lakes. The classical monitoring approach relies on microscopic identification and counting of phytoplankton species, which is time-consuming and requires high taxonomic expertise. High-throughput sequencing, combined with metabarcoding, has recently demonstrated its potential as an alternative approach for plankton surveys.

Environmental filtering and mass effect are two important processes driving lake benthic diatoms: Results of a DNA metabarcoding study in a large lake.

Environmental filtering is often found to dominate assembly rules in diatoms. These microalgae are diverse, especially at subspecies level, and tend to exhibit a niche phylogenetic conservatism. Therefore, other rules, such as competition or mass effects, should be detectable when environmental gradients and dispersal barriers are limited.