Table of Contents Table of Contents
Previous Page  31 / 60 Next Page
Show Menu
Previous Page 31 / 60 Next Page
Page Background


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.