Marine Microplastics Host Unique and Potentially Risky Microbial 'Cities'

Floating plastic debris is creating a new ecological niche in our oceans known as the 'plastisphere'. Researchers studying Yilan Bay in northeastern Taiwan utilised advanced genetic sequencing to reveal that microplastics harbour significantly more diverse microbial communities than the surrounding surface seawater. Unlike natural wood debris, which hosts diversity levels comparable to the water, plastic waste supports unique, complex networks of microorganisms.

These microscopic inhabitants are not merely hitchhikers; they form distinct biofilms—slimy layers of microorganisms sticking to a surface—with specific interactions driven by the plastic substrate. Analysis suggests these communities may actively function in nitrogen and sulfur cycling, and even hydrocarbon degradation. However, the findings raise a notable concern: the team detected putative pathogenic taxa on the plastics. This suggests that floating marine litter could act as a mobile reservoir for disease, transporting harmful microbes across ecosystems and posing potential risks to environmental and public health.