Among the challenges in addressing marine debris is that the greatest impacts are largely invisible from the origin of the debris (fugitive loss, litter, or other improper disposal). Someone who accidently drops a plastic wrapper while walking in the park is unlikely to see the damage done when that wrapper reaches the ocean.
Another significant challenge is that marine debris arises from sources around the world. Unilateral action by the United States will be helpful, but cannot, by itself, solve the problems presented by marine debris. Debris dropped anywhere on earth may end up being transported via surface water to the ocean where it may be carried vast distances before it settles to the bottom.
Furthermore, plastic debris is simply too widely dispersed to effectively clean it up. Even in the Great Pacific Garbage Patch there are only a few kilograms of plastic per square kilometer of ocean. This is roughly equivalent of a few teaspoons of plastic pieces spread over a football field and trying to clean it all up with tweezers. Reversing the impacts of plastic debris will take sustained efforts and novel technologies.
By far the best solution to plastic marine debris is to prevent the debris from entering the water system, either land-based debris (e.g., litter, fugitive releases from trash handling and landfills, etc.) washed into surface water or blown out to sea, or ocean-based (e.g., trash from ships or platforms, or derelict fishing gear). Efforts by a wide variety of organizations, including the U.S. EPA, National Oceanic and Atmospheric Administration, the United Nations Environment Programme, Intergovernmental Oceanographic Commission, and Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP), as well as nongovernmental organizations such as Algalita Marine Research Foundation, Surfrider Foundation, among others, have raised awareness of problems associated with marine debris and are due credit for the leveling off of the abundance of marine debris.
