“Out of sight, out of mind” is what overcomes most of us when thinking about garbage disposal. Research insights on the Great Pacific Garbage Patch might make us consider otherwise.
Tiny broken down plastic particles become ocean grub for small sea creatures, which in turn become food for larger sea creatures (and the cycle goes on and on). Particles of plastic could potentially enter our food chain from eating fish and other seafood. Plastic bits have been discovered in sea turtles and many poor ocean-dwelling birds.
More details on the GPGP and marine life: