Maciej Zbyszewski, Patricia L. Corcoran, Alexandra Hockin, Comparison of
the distribution and degradation of plastic debris along shorelines of
the Great Lakes, North America, Journal of Great Lakes Research,
Available online 17 March 2014, ISSN 0380-1330,
http://dx.doi.org/10.1016/j.jglr.2014.02.012.
(http://www.sciencedirect.com/science/article/pii/S038013301400046X)
Abstract: The distribution patterns, compositions and textures of
plastic debris along the Lake Erie and St. Clair shorelines were studied
in order to determine the roles of potential source locations, surface
currents, and shoreline types in the accumulation of plastic litter. The
results were compared with those previously determined from Lake Huron,
where abundant plastic pellets characterize the southeastern shoreline.
Lake Erie and St. Clair shorelines contained some pellets, but were
mainly characterized by plastic fragments and intact products,
respectively. The potential sources for the pellets include spillage
within factories or during transport and off-loading; whereas intact
products were derived from urban waste. Once entering the lake
environment, low density floating polymers such as polyethylene and
polypropylene were degraded by UVB radiation at either the water surface
or once deposited on shorelines. Mechanical degradation by wave action
and/or sand abrasion fragmented intact products into cm-size particles.
Certain textures identified on the surfaces of plastic particles could
be related to the nature of the depositional environment. Plastics
sampled from infrequently visited muddy, organic-rich shorelines were
characterized by more adhering particles and less mechanical pits than
those from sandy shorelines. In terms of relative distribution, the Lake
St. Clair shoreline contained the least amount of plastic debris of the
three lakes. This is a function of the breakwaters and retaining walls
built along Lake St. Clair, which replace natural sandy or muddy sinks
for floating polymers. This study represents the first detailed record
of plastics distribution along multiple, but related fresh water shorelines.
Keywords: Plastic debris; Great Lakes; SEM; FTIR; Shorelines; Pollution