Researchers are finding that ocean currents carry plastic pollution -- cigarette lighters, plastic bags and other trash -- from the world's coastlines to the middle of its oceans. Two experts answer your questions on the impact of plastic ocean pollution.
I'd like to know where all of this trash is coming from. What countries or regions is it coming from? How is it getting in the water? Does it come from military, container and cruise ships? Is it caused by littering near the ocean?
Holly Bamford responds:
Trash comes from everywhere, all over the globe. It is a direct product of human use. In our country alone, the U.S. Environmental Protection Agency has estimated that the average American discards four and a half pounds of trash every day. A percentage of this ends up as marine debris.
You don't have to live near the coast to have an effect on our ocean -- it can travel from areas that are not bordered by water. Many times this trash and debris is not disposed of properly or recycled and washes into a storm drain, which connects to our rivers, creeks and canals that lead to the ocean.
Debris may also come from direct sources such as ships or at-sea platforms either accidentally or intentionally. Currents and winds then move this debris in our oceans, far beyond its origin.
Remember, marine debris has no political boundaries. It is very difficult to identify the exact source or originating location for marine debris. Even an item with a U.S. label, for example, may have been purchased by a tourist, taken back to their country and discarded improperly. If this item was found on a beach in that country, it might be thought it was discarded in the U.S. and traveled to these distant shores, but it was actually discarded in another country.
There is no one way to create marine debris, but there is only one source - humans. And it is up to us to remedy this problem through research, removal and prevention of marine debris.
Charles Moore responds:
Many people have asked questions similar to yours about where the debris we find at sea comes from. The simple answer is that it comes from everywhere. None of your suppositions about major sources are correct, however. Only about 20 percent comes from ships at sea, and an even smaller fraction comes from beach users. The majority comes from urban centers into their storm drainage systems and "runs off" during rain events. The major contributors are Pacific Rim countries like the US, China, Japan, Mexico and on and on.
The truth is, we are all responsible, as plastic packaging and waste have become so ubiquitous that none of us are able to properly dispose of it all, much less recycle it.