http://dx.doi.org/10.1021/es503610r

Amanda McCormick, Timothy Hoellein, Sherri A Mason, Joseph Schluep, and
John J. Kelly
Microplastic is an abundant and distinct microbial habitat in an urban river
Environ. Sci. Technol., Just Accepted Manuscript
DOI: 10.1021/es503610r
Publication Date (Web): September 17, 2014

Abstract
Recent research has documented microplastic particles (< 5 mm in
diameter) in ocean habitats worldwide and in the Laurentian Great Lakes.
Microplastic interacts with biota in these habitats, including
microorganisms, raising concerns about its ecological effects. Rivers
may transport microplastic to marine habitats and the Great Lakes, but
data on microplastic in rivers is limited. In a highly urbanized river
in Chicago, Illinois, USA, we measured concentrations of microplastic
that met or exceeded those measured in oceans and the Great Lakes, and
we demonstrated that wastewater treatment plant effluent was a point
source of microplastic. Results from high-throughput sequencing showed
that bacterial assemblages colonizing microplastic within the river were
less diverse and were significantly different in taxonomic composition
compared to those from the water column and suspended organic matter.
Several taxa that include plastic decomposing organisms and pathogens
were more abundant on microplastic. These results demonstrate that
microplastic in rivers are a distinct microbial habitat and may be a
novel vector for the downstream transport of unique bacterial
assemblages. In addition, this study suggests that urban rivers are an
overlooked and potentially significant component of the global
microplastic life cycle.