Deep sea microbial variety, litterally

What microbial assemblages exist on deep sea anthropogenic litter?  This study collected 12 items and two sediment cores in the equatorial Atlantic including plastic, fabric, glass, rubber and metal.  Some 30,000 bacterial and archaeal 16S rRNA V4 sequences were identified and communities compared using PRIMER.

Each type of material showed that a large number of taxa were unique to that material, with only 3% of OTUs common to all. This suggests that each material type has different assemblages.  The diversity of prokaryotes on the metal substratum was much lower than other material and specialist iron-oxidising Zetaproteobacteria were present, a finding mirrored in studies of ferromanganese nodules. Length of time on the seabed and history since release were not known and could equally contribute to differences in biofilm community composition.

All litter types were colonised suggesting that the notion of a Plastisphere can be extended to a Litterosphere.  This is interesting work being the first attempt to answer this question. The inherent difficulty of sampling at deep remote locations means we will need more replication and samples to understand deep sea biofilms and the effect we are having on ecosystem processes.

Woodall L.C. et al. (2019). Deep-sea anthropogenic macrodebris harbours rich and diverse communities of bacteria and archaea. PLos One 13 (11), e0206220