VIDEO: Plastic in oceans 'threatens food chain'
As England prepares to introduce a charge for plastic bags, Science Editor David Shukman reports on the possible threat to the food chain, by the plastics broken down into tiny fragments in our oceans.As England prepares to introduce a charge for plastic bags, Science Editor David Shukman reports on the possible threat to the food chain, by the plastics broken down into tiny fragments in our oceans.