Ocean Pollution

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Sea turtle eating plastic confused for a jellyfish

No, it isn't the name of a new science fiction movie. The plastic island, or garbage patch, is a collection of marine debris that starts off life as litter from land and ends up trash in the ocean. It congregates together in areas thanks to ocean currents. Most garbage patches, including the famed Great Pacific Garbage Patch, is comprised of plastic.

Contrary to the image that a plastic island brings up, this ocean pollution is not a giant island of trash. In fact, it is almost entirely made up of tiny bits called microplastic which cannot always be seen by the naked eye. Microplastics tend to look more like cloudy soup. Larger items like shoes and fishing gear can be seen floating amongst this soup. Also, oceanographers and ecologists have recently discovered that about 70% of garbage in the ocean sinks to the bottom so there may be more trash on the sea floor beneath these so-called plastic islands.

Great Pacific Garbage Patch

Great Pacific Gargabe Patch

The best known plastic island is the Great Pacific Garbage Patch, also known as the Pacific trash vortex. It spans between the West Coast of North America to Japan. It is comprised of two different patches - one near Japan called the Western Garbage Patch and one between Hawaii and California known as the Eastern Garbage Patch. The two areas feed ocean pollution to each other thanks to the North Pacific Subtropical Convergence Zone. This is where warm water from the South Pacific meets with cool water from the Arctic, creating a current that moves between the two areas.

No one knows for sure how much trash makes up the Great Pacific Garbage Patch. What we do know is that about 80% of the garbage comes from activities in North America and Asia. The other 20% comes from boaters and large ships. Scientists believe that it takes about six years for trash to reach the patch from North America and a year from Asia.

Most of the debris in the patch are not biodegradable. As mentioned earlier, it is mostly plastic that breaks into tiny pieces called microplastics.

While no one nation is taking responsibility for cleaning up the patch, many people and organizations are taking steps to preventing the patch from growing larger. However, scientists agree that limiting or eliminating the use of disposable plastic for more biodegradable options is our best bet for preventing the ocean pollution from increasing.

Ocean Pollution Facts

As stated before, over 80% of ocean pollution is the result of land-based activities. While trash in the sea is certainly a big part of the problem, there are other types of pollution that also threaten the health of the sea and the organisms that live in it.

Garbage: Plastic bags, balloons, bottles, shoes, and packaging material can quickly reach the ocean if not disposed of properly. Marine life, such as sea turtles, sometimes mistake plastic bags for prey like jellyfish. Plastic bags have also been found blocking breathing passages and stomachs of whales, seals, dolphins, and puffins. Plastic six-pack rings can also choke marine animals.

Oil: Oil from spills is well-known to be hazardous to ocean dwellers. However, spills only represent about 12% of the oil that enters the ocean each year. Most come from drains and rivers as waste and runoff from cities and industrial areas.

Fertilizer: Fertilizer runoff does make its way to the oceans from farms and lawns. It is particularly dangerous for coastal regions. Fertilizers add extra nutrients to the water that cause algae to overpopulate areas, depleting the water of oxygen. The lack of oxygen suffocates other marine life and causes what are known as "dead zones" where no marine life other than this algae exists. There are two large dead zones in the Gulf of Mexico and the Baltic Sea.

Sewage: In some parts of the world, untreated sewage flows into the ocean. In fact, 80% of the sewage released into the Mediterranean is untreated. This sewage can cause a similar effect to fertilizer runoff. It can also lead to human disease and beach closures.

Toxic Chemicals: Finally, manmade chemicals can be found in almost every marine organism from plankton to whales. These include pesticides and chemicals used in everyday products. Some of the chemicals come from deliberate dumping while others escape into the water during manufacture or use. Not only do these chemicals affect and even poison sea organisms, but humans can also become contaminated from eating affected seafood.