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 bays.

The Great Pacific Garbage Patch is not the only marine trash patch, but it is the biggest. It spans waters from the West Coast of North America to Japan. The patch is actually made up of two parts: the Western Garbage Patch, located near Japan, and the Eastern Garbage Patch, located between Hawai'i and California.

The entire Great Pacific Garbage Patch is bounded by the North Pacific Subtropical Gyre. A gyre is a large system of swirling ocean currents. The area in the center of a gyre tends to be very calm and stable. The circular motion of the gyre draws debris into this stable center, where it becomes trapped.

A plastic water bottle discarded off the coast of California, for instance, takes the California Current, south toward Mexico. There, it may catch the North Equatorial Current, which crosses the vast Pacific. Near the coast of Japan, the bottle may travel north on the powerful Kuroshio Current. Finally, the bottle travels eastward on the North Pacific Current. The gently rolling vortexes of the Eastern and Western Garbage Patches slowly draw in the bottle.

The amount of debris 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 summons up images of an island of trash floating on the ocean. In fact, these patches are almost entirely made up of tiny bits of plastic, called microplastics. The debris cannot always be seen by the naked eye. It can simply make the water look like a cloudy soup. Larger items, such as fishing gear and shoes, are mixed into this soup.

The seafloor beneath the Great Pacific Garbage Patch may also be an underwater trash heap. About 70 percent of marine debris eventually sinks to the bottom of the ocean.

Marine Debris Clutters Ocean

Most plastic in the ocean comes from land-based sources, but some of it comes from marine sources. A lot of plastic from boats has accumulated in the Great Pacific Garbage Patch. A 2018 study found that fishing nets alone made up nearly half its mass.

While many different types of trash enter the ocean, plastics make up the majority of marine debris for two reasons. First, plastic's durability and low cost mean that it's being used in more and more consumer and industrial products. Second, plastic goods do not biodegrade but instead break down into smaller pieces.

In the ocean, the sun breaks down these plastics into tinier and tinier pieces. Most of this debris comes from plastic bags, bottle caps, plastic water bottles and Styrofoam cups.

Marine debris can be very harmful to marine life in the gyre. For instance, loggerhead sea turtles often mistake plastic bags for jellies, their favorite food. Albatrosses can mistake plastic resin pellets for fish eggs. They then feed the pellets to their chicks, which die of starvation or ruptured organs.

Seals and other marine mammals are especially at risk. They can get entangled in abandoned plastic fishing nets. Seals and other mammals often drown in these forgotten nets.

Marine debris can also disturb marine food webs in the North Pacific Subtropical Gyre. As microplastics and other trash collect on or near the surface of the ocean, they block sunlight from reaching plankton and algae below. If these marine plants are threatened, the entire food web may change. Animals that feed on algae and plankton, such as fish and turtles, will have less food. If their populations decrease, there will be less food for the animals that feed on them, such as tuna, sharks and whales.

These dangers are worsened by the fact that plastics both release and absorb harmful pollutants. As plastics break down, they release chemicals that have been linked to environmental and health problems. Plastics can also absorb pollutants from the seawater. These chemicals can then enter the food chain when consumed by marine life.

Cleaning up the Patch

Because the Great Pacific Garbage Patch is so far from any country's coastline, no nation will take responsibility for cleaning it up. However, many international organizations are dedicated to preventing the patch from growing.

Cleaning up marine debris is not as easy as it sounds. Many microplastics 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 far too time-consuming to consider. Scientists estimate that it would take 67 ships one year to clean up less than one percent of the North Pacific Ocean.

Scientists agree there is a better way to clean up the Great Pacific Garbage Patch: The countries of the world must limit or end their use of disposable plastics.