http://pubs.acs.org/doi/abs/10.1021/es4053076

Kara Lavender Law, Skye Moret-Ferguson, Deborah S. Goodwin, Erik R.
Zettler, Emelia DeForce, Tobias Kukulka, and Giora Proskurowski
Distribution of surface plastic debris in the eastern Pacific Ocean from
an 11-year dataset
Environ. Sci. Technol., Just Accepted Manuscript
DOI: 10.1021/es4053076
Publication Date (Web): April 7, 2014

Abstract
We present an extensive survey of floating plastic debris in the eastern
North and South Pacific Oceans from more than 2,500 plankton net tows
conducted between 2001 and 2012. From these data we defined an
accumulation zone (25 to 41°N, 130 to 180°W) in the North Pacific
subtropical gyre that closely corresponds to centers of accumulation
resulting from the convergence of ocean surface currents predicted by
several oceanographic numerical models. Maximum plastic concentrations
from individual surface net tows exceeded 106 pieces km-2, with
concentrations decreasing with increasing distance from the predicted
center of accumulation. Outside the North Pacific subtropical gyre the
median plastic concentration was 0 pieces km-2. We were unable to detect
a robust temporal trend in the dataset, perhaps because of confounded
spatial and temporal variability. Large spatio-temporal variability in
plastic concentration causes order of magnitude differences in summary
statistics calculated over short time periods or in limited geographic
areas. Utilizing all available plankton net data collected in the
eastern Pacific Ocean (17.4°S to 61.0°N; 85.0 to 180.0°W) since 1999, we
estimated a minimum of 21,290 metric tons of floating microplastic.

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