Preproduction Plastic Pellets, also known as knurdles, are the raw material that is used to manufacture virually all plastic products.

Oceangybe was collecting samples of these around the world for the Pellet Watch program in Japan. Recently a large number washed up on beached in Lake Huron:
http://tiny.cc/ibayf

It appears that it is time for Canada to address is this problem as California has:
http://tiny.cc/t959k