At the forefront of the many problems plaguing our planet is the issue of the ubiquitous plastic bag.
  More now than ever, people need to be aware of the effect plastic debris is having on our oceans and make the switch to reusable bags.
  Along with runoff from coastal landfills and storm drain discharges, sewage overflows, and contamination from industrial activities, plastics are a major source of marine pollution.
  In a report entitled Plastic Debris in the World's Oceans, 60-80% of the nearly 6-1/2 tons of trash entering the oceans annually consists of plastic debris.
  Given the sheer numbers of bags the world's population goes through every year (estimated to be between 500 billion and a trillion) it follows that plastic bags make up a significant portion of that trash.
  A study published in the Marine Pollution Bulletin in the 1990's revealed that on the ocean floor around the coasts of Spain, France and Italy over 75% of the debris consisted of plastics, and over 90% of that was made up of plastic bags.
People around the world can have a significant effect on this problem by simply investing in a few reusable shopping bags, and using them consistently.
As vast as the oceans are, it is difficult to quantify the amount of trash in them.
  However, a 2006 study published by the United Nations Environment Programme determined that there is an estimated 18,000 pieces of floating plastic garbage on average per square kilometer of ocean.
  The infamous North Pacific Gyre (a.
k.
a.
The Great Pacific Garbage Patch) which is located between Hawaii and California contains an estimated average of over 330,000 pieces of litter per square kilometer.
  In some areas, the density rises to nearly one million pieces per square kilometer.
Much of this floating debris consists of plastics:  films, plastic fragments, fishing line and other plastic materials.
   It is kept in place by clockwise ocean currents, and therefore does not reach land, making it difficult to remove the debris from the water.
  Another study published in 2001 and conducted by the Algalita Marine Research Foundation states that plastic fragments in the Gyre outweigh surface zooplankton by as much as six times.
When so much plastic winds up in the ocean, marine life is jeopardized.
Not only is there potential for entanglement and intoxication from chemicals in the plastic, but ingestion is can be devastating to many species of sea turtles, birds and marine mammals.
  Since plastics photo-degrade into microscopic pieces, it is impossible for sea life to avoid ingesting it.
  Additionally, some animals may mistake pieces of plastic for prey.
  Greenpeace studies on dead sea turtles have discovered ingestion of marine debris in 56%-79% of the animals.
  The increase in the mortality rate of albatross chicks is also linked to plastic debris.
  Not only can ingested plastic interfere with the digestive system of an animal by clogging it or causing them to eat less actual food, their bodies may retain harmful chemicals, as plastics can absorb PCBs and other harmful chemicals that persist in the environment.
  Traveling on up through the food chain, this poses a threat to human health as well.
  Without question, people must reduce the use of plastic bags and seek other alternatives, such as shopping with reusable grocery bags.