Methodology optimization to quantify microplastic presence in planktonic copepods, chaetognaths and fish larvae

Area of Science:

• Environmental Science
• Marine Biology
• Analytical Chemistry

Background:

• Microplastics (MPs) pose significant risks to marine life, particularly zooplankton and fish larvae, through ingestion and absorption.
• Current methods for quantifying MPs in plankton lack standardization and can alter plastic characteristics, leading to underestimation.
• There is a critical need for a reliable methodology to accurately assess MP contamination in marine organisms.

Purpose of the Study:

• To optimize a standardized methodology for quantifying microplastics (MPs) in zooplankton and fish larvae.
• To ensure the integrity and characteristics of microplastics are preserved during the digestion process.
• To develop a rapid and efficient protocol for microplastic analysis in planktonic organisms.

Main Methods:

• Digestion of planktonic organisms using 30% (v/v) hydrogen peroxide (H₂O₂) solution at varying temperatures and incubation times.
• Analysis of microplastic characteristics (color, size, polymer type) before and after digestion using visual inspection and Fourier Transform Infrared Spectroscopy (FTIR).
• Testing the methodology's efficiency with 13 different types of microplastics, including fibers and fragments of various polymers.

Main Results:

• The optimized methodology successfully digested planktonic tissues while preserving the integrity of all 13 tested microplastic types.
• Microplastic recovery rates exceeded 85% for all tested plastic types.
• No observable changes in microplastic color, size, or polymer characteristics were detected post-treatment.

Conclusions:

• The developed protocol provides a rapid (max 7h incubation) and effective means to quantify microplastics in zooplankton and fish larvae.
• This standardized method ensures accurate assessment of microplastic contamination by maintaining plastic integrity.
• The findings contribute to a better understanding of microplastic pollution impacts on marine ecosystems.