Objective:

To investigate the presence of microplastics in deep-sea animals from hydrothermal vents and understand their connection to surface-derived plastic pollution.

Approach:

• Study Design: The study compared vent fauna from the North Fiji Basin and the Central Indian Ridge, analyzing provannid snails and modiolid mussels using mitochondrial COI DNA barcoding.
• Analytical Methods: The workflow included hydrogen peroxide digestion, density separation, filtration, stereomicroscopic screening, and FTIR microscopy for polymer identification.

Key Findings:

• Microplastics were detected in 92% of the examined animals, corresponding to 11 of 12 specimens.
• A total of 40 microplastic particles were identified, predominantly fragments, with polystyrene being the most common polymer.
• Feeding behavior influenced microplastic accumulation, with grazing snails showing higher concentrations in internal organs and filter-feeding mussels having a more even distribution across tissues.
• Animals from the Indian Ocean had higher microplastic loads and a broader polymer profile compared to those from the southwestern Pacific.

Interpretation:

The findings show that plastic pollution has reached deep-sea hydrothermal vent ecosystems.

Limitations:

• FTIR microscopy does not capture particles smaller than 20 µm, potentially underestimating total microplastic exposure.

Conclusion:

The study highlights the need for monitoring microplastics in deep-sea environmental assessments.

Sources:

• Korea Research Institute of Bioscience and Biotechnology