The reason why fish eat plastic when it is dumped in the ocean has been discovered by scientists.

Tests on anchovies show that when plastic is mixed with salt water and begins to disintegrate it releases an odour which is similar to krill.

The enticing smell sets of foraging and feeding behaviour in fish, causing them to eat the debris, believing it is food.

Previously scientists thought that fish were ingesting tiny particles of plastic by accident when they were hoovering up floating pieces of plankton or krill. But the new study suggests the problem is even more serious, because fish are actually attracted to the plastic.