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Marine Litter
Vital Graphics
In addition to direct input of microplastics resulting
from human activities, plastic debris already present
in the environment can be a very significant source of
microplastics. Plastic debris will progressively become
brittle under the action of ultraviolet light and heat and
then fragment under physical action from wind and waves
into tiny microplastic pieces (Andrady, 2015). Due to the
abundance of plastic debris in the marine environment
this is likely to represent a major source of microplastic
(Andrady, 2011) in future years, even if prevention measures
drastically reduce the inflow of large objects. Processes
that produce marine microplastics include fragmentation
of plastic debris in the sea by physical and chemical
weathering; biologically mediated fragmentation of plastic
debris at sea or in the coastal zone through digestion in
birds and other macrofauna; boring and transport ashore
allowing increased physical and chemical weathering;
and remobilization of plastic polluted sediments or soils.
SOURCES