A really interesting article about ocean debris from National Geographic:
The Great Pacific Garbage Patch is a collection of marine debris in the North Pacific Ocean. Marine debris is litter that ends up in oceans, seas, and other large bodies of water.
The Great Pacific Garbage Patch, also known as the Eastern Pacific Garbage Patch and the Pacific Trash Vortex, lies in a high-pressure area between the U.S. states of Hawaii and California. This area is in the middle of the North Pacific Subtropical Gyre.
An ocean gyre is a circular ocean current formed by the Earth’s wind patterns and the forces created by the rotation of the planet. The area in the center of a gyre tends to be very calm and stable. The circular motion of the gyre draws in debris. Debris eventually makes its way into the center of the gyre, where it becomes trapped and builds up. A similar garbage patch exists in the Atlantic Ocean, in the North Atlantic Gyre.
The motion of the gyre prevents garbage and other materials from escaping. The amount of material in the Great Pacific Garbage Patch accumulates because much of it is not biodegradable. Many plastics, for instance, do not wear down; they simply break into tinier and tinier pieces.
For many people, the idea of a “garbage patch” conjures up images of an island of trash floating on the ocean. In reality, these patches are usually made up of tiny bits of plastic, called microplastics. Microplastics that make up the majority of garbage patches can’t always be seen by the naked eye. Satellite imagery of oceans doesn’t show a giant patch of garbage.
The existence of the Great Pacific Garbage Patch was predicted by many oceanographers and climatologists. However, the actual discovery of the patch was made by a racing boat captain, Charles Moore. Moore was sailing from Hawaii to California after competing in a yachting race. Crossing the North Pacific Subtropical Gyre, Moore and his crew noticed millions of pieces of plastic surrounding his ship.
Marine Debris
Any kind of trash can get into the ocean—from glass bottles to aluminum cans to medical waste. The vast majority of marine debris, however, is plastic. Scientists have collected up to 750,000 bits of plastic in a single square kilometer (or 1.9 million bits per square mile) of the Great Pacific Garbage Patch.
Plastic products can be very harmful to marine life in the gyre. For instance, loggerhead sea turtles often mistake plastic bags for jellyfish, their favorite food. And many marine mammals and birds, such as albatrosses, have become strangled by the plastic rings used to hold six-packs of soda together.
Marine debris can also disturb marine food webs in the North Pacific Subtropical Gyre. As microplastics and other trash collect on the surface of the ocean, they block sunlight from reaching plankton and algae below. Algae and plankton are the most common autotrophs in the marine food web. Autotrophs are organisms that can produce their own nutrients from oxygen, carbon, and sunlight.
If algae and plankton communities are threatened, the entire food web may change. Animals such as fish and turtles that feed on algae and plankton will have less food. If those animals start to die, there will be less food for predator species such as tuna, sharks, and whales.
The Great Pacific Garbage Patch collects marine debris from North America and Asia, as well as ships traveling through the area. Trash from the coast of North America takes about six years to reach the Great Pacific Garbage Patch, while trash from Japan and other Asian countries takes about a year.
No one knows how much debris makes up the entire patch. The North Pacific Subtropical Gyre is about 19 million square kilometers (7 million square miles). It is too large for scientists to trawl the entire surface. In addition, not all of the trash floats on the surface. Denser debris can sink to the middle or bottom of the water. We have no way to measure this unseen litter.
Patching Up the Patch
Because the Great Pacific Garbage Patch is so far from any country’s coastline, no nation will take responsibility or provide the funding to clean it up. Many international organizations, however, are dedicated to preventing the patch from growing any further.
Cleaning up marine debris is not as easy as it sounds. Many pieces of debris are the same size as small sea animals, so nets designed to scoop up trash would catch these creatures as well. Even if we could design nets that would just catch garbage, the size of the oceans makes this job too time-consuming to consider. And no one can reach trash that has sunk to the ocean floor.
Many expeditions have traveled through the Great Pacific Garbage Patch. Charles Moore, who discovered the patch in 1997, continues to raise awareness through his own environmental organization, the Algalita Marine Research Foundation.
All the floating plastic in the Great Pacific Garbage Patch inspired National Geographic Emerging Explorer David de Rothschild and his team at Adventure Ecology to create a large catamaran made of plastic bottles: the Plastiki. The sturdiness of the Plastiki displayed the strength of plastics and the threat they pose to the environment when they don’t decompose. In 2010, the crew successfully navigated the Plastiki from San Francisco, California, to Sydney, Australia.
