A small bacteria feeding on it has been discovered. This may be a boon or a bane for the aquatic environment.
The bacteria was discovered through electron microscopy on plastic items sampled at the Sargasso Sea, an area in the North Atlantic, where debris tends to stack up due to local currents.

The primitive organisms live in pits in the plastic and appear to feed on it as well, says marine microbiologist Tracy Mincer of the Woods Hole Oceanographic Institution in Massachusetts.

"They look like you took a hot barbecue briquette and threw it into snow," Nature News cites Mincer as saying. "You see this melting bit all around the outside of the cells, and they're just burrowing into the plastic."

Image from state-of-affairs.org

The specialized bug is not encountered in other environment, like surrounding seawater or seaweed.

Scientists are not yet sure whether these organisms will eventually do more good than harm in dealing with pollution. If their digestion products are environmentally-friendly, then it would mean that nature has found a new way to limit the damage humanity does.

But plastic contains numerous toxins, and the bacteria may be introducing those into the food chain by feeding on it and then becoming food for larger organism.

Source: myscienceacademy.org & RT.com