Microplastic type and concentration affect prokaryotic community structure and species coexistence in deep-sea cold seep sediments.

Summary: Deep beneath the ocean surface, "cold seeps" act as vital storage sites for methane and host unique microbial communities. However, these remote ecosystems are now facing a modern threat: plastic pollution. Researchers investigated how microplastics—specifically nylon (PA), polyethylene (PE), plastic bottle material (PET), and polypropylene (PP)—affect the tiny bacteria and archaea living in deep-sea sediments.

By adding these plastics to sediment samples in a lab, they discovered that the plastics didn't just sit there; they significantly disrupted the microbial neighborhood. The presence of plastics, particularly PE and PET, altered which species thrived and which struggled. More importantly, the "social networks" of these microbes became less complex and less stable, making the community more fragile. On a surprising note, some plastics showed chemical signs of being eaten (biodegraded) by the microbes. This study confirms that even the deep sea is vulnerable to the destabilizing effects of plastic pollution.