Quantification of marine benthic communities with metabarcoding

Area of Science:

• Marine Ecology
• Molecular Biology
• Biodiversity Assessment

Background:

• DNA metabarcoding is used for marine benthic biodiversity detection.
• Quantifying biodiversity with DNA metabarcoding requires a link between DNA sequences and organism biomass/abundance.
• This relationship is often complex and unknown.

Purpose of the Study:

• To validate biomass and abundance estimates from molecular approaches against traditional morphological methods.
• To assess the reliability of DNA metabarcoding for quantifying benthic invertebrate populations.

Main Methods:

• Collected 126 benthic intertidal mudflat samples.
• Quantified abundance and biomass using traditional morphological approaches.
• Compared these with frequency of occurrence and relative read abundance from DNA metabarcoding.

Main Results:

• A relationship between biomass and relative read abundance was identified for two annelid taxa (Pygospio and Scoloplos).
• No such relationship was found for other studied taxa.
• The study highlights limitations in using DNA metabarcoding for precise biomass/abundance quantification.

Conclusions:

• Quantification of benthic biodiversity using DNA metabarcoding is challenging due to complex ecological factors and DNA processes.
• The relationship between DNA reads and biomass/abundance is taxon-specific and not universally applicable.
• Further research is needed to refine molecular methods for accurate ecological assessments.