Using eRNA/eDNA metabarcoding to detect community-level impacts of nanoplastic exposure to benthic estuarine...

Area of Science:

• Environmental Science
• Marine Biology
• Ecotoxicology

Background:

• Plastic particles, including nanoplastics (NPs), are pervasive in marine environments.
• Marine sediments harbor ecologically vital benthic micro- and meiofauna, yet their sensitivity to NPs remains poorly understood.
• Assessing NP impacts on community diversity and composition is crucial for understanding ecosystem health.

Purpose of the Study:

• To investigate the effects of nanoplastics on benthic micro- and meiofaunal community diversity using a metabarcoding approach.
• To determine if nanoplastics induce dose-dependent shifts in marine sediment communities.

Main Methods:

• Mesocosms containing sediment cores were exposed to weathered polystyrene nanoplastics (900 nm diameter) at varying concentrations (0.1–100 mg/kg).
• Molecular methods, including environmental DNA/RNA metabarcoding targeting 18S and COI markers, were employed.
• High-throughput sequencing (Illumina MiSeq) analyzed amplicon libraries derived from co-extracted DNA and RNA.

Main Results:

• Increased alpha-diversity and significant differences in beta-diversity were observed at the highest nanoplastic exposure levels.
• Community composition shifts were driven by changes in protist and arthropod abundance.
• Significant, dose-dependent changes in community composition were detected using 18S rRNA gene sequencing of the eRNA template.

Conclusions:

• This study provides the first evidence of a dose-response relationship for nanoplastics at the community level in marine sediments.
• Metabarcoding of environmental RNA is a valuable tool for assessing the ecological impacts of nanoparticles on benthic communities.
• Nanoplastics can alter the diversity and composition of ecologically important benthic micro- and meiofaunal communities.