Scientists examining the devastating impact plastics are having on the world's oceans have identified seabirds with more than 250 man made objects lodged in their stomachs.

From bottle tops to pen lids, the flesh footed shearwaters are thought to consume more plastic than any other marine animal.

Often mistaking plastic objects floating in the sea for food, the adult birds pick them up and then feed them to their young, with disastrous consequences.

Researchers working on Lord Howe island, off the coast of Australia, where the flesh footed shearwaters nest, claim that on average every chick has between 30 and 40 pieces of jagged plastic in their stomachs before they are fully fledged.