Microplastics in global bivalve mollusks: A call for protocol standardization.

Area of Science:

• Environmental Science
• Marine Biology
• Ecotoxicology

Background:

• Microplastic pollution is a global concern, with bivalve mollusks frequently found to contain microplastics.
• Inconsistent research methodologies hinder the comparison of microplastic data across studies.
• Understanding factors influencing microplastic accumulation in bivalves is crucial for human health risk assessment.

Purpose of the Study:

• To synthesize current knowledge on microplastics in global bivalve mollusks.
• To analyze factors affecting microplastic data, focusing on bivalve species and methodologies.
• To propose standardized protocols for microplastic monitoring in bivalves.

Main Methods:

• Systematic review of 61 peer-reviewed scientific papers.
• Analysis of microplastic abundance data in relation to bivalve families, genera, and habitats.
• Evaluation of different sampling, processing, and analytical techniques.

Main Results:

• Microplastic abundance varied significantly among bivalve families, suggesting habitat influences ingestion.
• No significant differences in microplastic abundance were found among genera within the same family.
• Epifaunal and infaunal bivalves show potential for monitoring microplastics in water and sediment, respectively.

Conclusions:

• Habitat is a critical determinant of microplastic ingestion in bivalve mollusks.
• Standardized protocols are essential for reliable, large-scale microplastic monitoring programs.
• Recommended protocol includes a sample size of at least 50 bivalves, 10% KOH digestion, and <5 µm filter pore size.