Microplastics in fish and fishmeal: an emerging environmental challenge?

Area of Science:

• Environmental Science
• Marine Biology
• Ecotoxicology

Background:

• Microplastics are pervasive environmental contaminants ingested by marine organisms.
• Fishmeal production utilizes a significant portion of global fish landings, creating a potential pathway for microplastic transfer.
• Existing research on microplastics in fishmeal-relevant species is limited by methodological inconsistencies.

Purpose of the Study:

• To review and assess the existing literature on microplastic contamination in fishmeal-relevant species.
• To validate a method for microplastic extraction from fishmeal.
• To quantify microplastic contamination in commercial fishmeal products.

Main Methods:

• Literature review of studies on microplastics in fishmeal-relevant species.
• Validation of a density separation method for microplastic extraction from fishmeal.
• Quantification of microplastics in two commercial fishmeal samples.

Main Results:

• 55% of reviewed studies were unsuitable due to methodological limitations.
• Fishmeal-relevant species contained an average of 0.72 microplastics/individual, primarily in digestive organs.
• Commercial fishmeal samples averaged 123.9 microplastics/kg, predominantly polyethylene and rayon microfibers.
• Microplastic concentrations in processed fishmeal may be higher than in captured fish.
• Over 300 million microplastic particles could be released annually via marine aquaculture.

Conclusions:

• Fishmeal represents a significant source and vector for microplastic contamination in marine environments and the food chain.
• Validated extraction methods are crucial for accurate microplastic assessment in complex matrices like fishmeal.
• Urgent attention is needed to mitigate microplastic release from fishmeal production and aquaculture to protect marine ecosystems and human health.