Plastic litter is killing sea life. This recent Raw Story tells the sad story of a “.. 4.5 tonne sperm whale that washed ashore in southern Spain died from ingesting large amounts of plastic sheets used in greenhouses on farms in the region…” (link)
Plastic floats and can last for many years in the marine environment. That plastic soda bottle or piece of plastic that you drop may wind up in a fish or sea mammal. Please be responsible with your plastic waste.