By The Economist
ANTHONY RICCIARDI, a scientist at McGill University, was looking for evidence that an invasive Asian clam had colonised a warm spot in the St Lawrence river when a member of his team made a more headline-worthy discovery. Peering through a microscope at sand scooped up from the riverbed, the student saw hundreds of tiny plastic spheres that stood out for their perfect roundness and unnatural colours.
http://www.economist.com/news/americas/21660287-abrasives-toothpaste-and-face-scrubs-are-poisoning-fish-firms-and-governments-are-starting-ban