Microbial communities on plastic particles in surface waters differ from subsurface waters of the North Pacific Subtropical Gyre

The long-term fate of plastics in the ocean and their interactions with marine microorganisms remain poorly understood. In particular, the role of sinking plastic particles as a transport vector for surface microbes towards the deep sea has not been investigated. Here, we present the first data on the composition of microbial com-munities on floating and suspended plastic particles recovered from the surface to the bathypelagic water column (0-2000 m water depth) of the North Pacific Subtropical Gyre. Microbial community composition of suspended plastic particles differed from that of plastic particles afloat at the sea surface. However, in both compartments, a diversity of hydrocarbon-degrading bacteria was identified. These findings indicate that microbial community members initially present on floating plastics are quickly replaced by microorganisms acquired from deeper water layers, thus suggesting a limited efficiency of sinking plastic particles to vertically transport microor-ganisms in the North Pacific Subtropical Gyre.

Automated summary

The long-term fate of plastics in the ocean and their interactions with marine microorganisms are still not well understood. This study investigated the role of sinking plastic particles as a transport vector for surface microbes towards the deep sea in the North Pacific Subtropical Gyre. The composition of microbial communities on floating and suspended plastic particles was analyzed, revealing differences between the two compartments but a presence of hydrocarbon-degrading bacteria in both. The findings suggest a limited efficiency of sinking plastic particles in vertically transporting microorganisms in this region.