Living in the anthropocene: plastic debris as a new bacterial habitat

Despite the devastating impact of plastic debris on marine life, plastic in the seas and oceans could be beneficial for some organisms too, as they could use this new material as a habitat or even as food source.
We evaluated the bacterial colonisation of marine plastic debris, in search of organisms that could potentially degrade plastic in marine environments. Five areas in the North Sea were sampled for plastic, sediment and water at two time points. Using 16S rDNA amplicon sequencing, bacterial communities for the three sample types were studied.
Our results show a large variation of bacterial communities between individual pieces of plastic, but these were always clearly distinct from that of seawater and sediment. Some bacterial families identified on plastics, e.g. Vibrionaceae and Pseudoalteromonadaceae, are rarely found in sediment and seawater. This indicates that the plastic surface represents a specific environmental niche, and suggests that plastic could act as transport vector for organisms. Additionally, we show that variation in the composition of the plastic bacterial community may be correlated with three different factors: environmental parameters (e.g. salinity), plastic-related factors (e.g. colour) and various stages of biofilm formation.
How these individual parameters influence the composition of bacterial communities is currently unclear. Therefore, we established an experiment, by which we expose plastic to the marine environment during one year, sampling once a month. This will provide information on the bacterial plastic community dynamics and on the existence of organisms that could be able to biodegrade plastic debris.