Abstract
Universally, concerns are mounting over the ubiquitous increase in plastic in waterways and oceans
of the world. It is commonly stated that about 80% of plastic waste enters the seas from land-based
sources, of which about 90% flows down waterways to the seas. The resultant plastic pollution of the
oceans is associated with serious negative environmental, ecological and economic consequences:
marine life is severely affected by entanglement, ingestion and chemical pollutants; human health is
also affected, and there are economic repercussions from the impacts on fisheries, shipping and
tourism. Depending on local conditions, differing proportions of plastic debris end up on beaches, or
sink into demersal habitats, or float off into the ocean to perhaps contribute to the oceanic gyres.
The percentages given for plastics flowing to the seas from land-based sources are generalizations
based on global estimates that are not necessarily supported by solid data. They are nevertheles.....