Role of marine snows in microplastic fate and bioavailability.
Environmental Science and Technology
American Chemical Society
© 2018 American Chemical Society
Reason for embargo
Under embargo until 21 May 2019 in compliance with publisher policy.
Microplastics contaminate global oceans and are accumulating in sediments at levels thought sufficient to leave a permanent layer in the fossil record. Despite this, the processes that vertically transport buoyant polymers from surface waters to the benthos are poorly understood. Here we demonstrate that laboratory generated marine snows can transport microplastics of different shapes, sizes, and polymers away from the water surface and enhance their bioavailability to benthic organisms. Sinking rates of all tested microplastics increased when incorporated into snows, with large changes observed for the buoyant polymer polyethylene with an increase in sinking rate of 818 m day-1 and for denser polyamide fragments of 916 m day-1. Incorporation into snows increased microplastic bioavailability for mussels, where uptake increased from zero to 340 microplastics individual-1 for free microplastics to up to 1.6 × 105 microplastics individual-1 when incorporated into snows. We therefore propose that marine snow formation and fate has the potential to play a key role in the biogeochemical processing of microplastic pollution.
This work was funded by a University of Exeter, Cefas (Centre for Environment, Fisheries and Aquaculture Science) Case Studentship. T.G. and C.L. acknowledge support from NERC grant NE/L007010.
This is the author accepted manuscript. The final version is available from American Chemical Society via the DOI in this record.
Vol. 52 (12), pp. 7111-7119.
Place of publication