North Atlantic deep-sea benthic biodiversity unveiled through sponge natural sampler DNA

Area of Science:

• Marine Biology
• Deep-Sea Ecology
• Biodiversity Monitoring

Background:

• Deep-sea ecosystems, particularly sponge grounds, are highly diverse and vulnerable to anthropogenic disturbances.
• Environmental DNA (eDNA) metabarcoding is a powerful tool for biodiversity monitoring, but assessing complex deep-sea benthic environments remains challenging.
• Deep-sea sponges are known to accumulate environmental DNA, presenting an opportunity for novel sampling strategies.

Purpose of the Study:

• To evaluate the effectiveness of using sponge tissues for whole-community eDNA metabarcoding to characterize metazoan diversity in North Atlantic deep-sea sponge grounds.
• To assess the potential of deep-sea sponges as natural samplers for high-resolution biodiversity monitoring.

Main Methods:

• Collected 97 sponge tissue samples from four species across four North Atlantic biogeographic regions.
• Screened samples using the universal COI barcode region for eDNA metabarcoding.
• Analyzed metazoan diversity and spatial patterns in relation to latitude and depth.

Main Results:

• Recovered unprecedented taxonomic diversity per unit effort, identifying at least 406 metazoan species.
• Detected significant spatial patterns in species assemblages related to latitude and depth.
• Identified emblematic species crucial for indicating the health of vulnerable deep-sea habitats.

Conclusions:

• Whole-community metabarcoding of sponge tissues is a highly effective method for characterizing deep-sea metazoan diversity.
• Deep-sea sponges act as excellent natural samplers, offering a high-resolution biomonitoring solution for vulnerable ecosystems.
• This approach demonstrates vast potential for monitoring diverse and sensitive deep-sea environments across different regions and species.