Human Impact- Case Study 1 - The Great Pacific Garbage Patch

Each year, three times as much rubbish is dumped into the world's oceans as the weight of fish caught.

So what is the Great Pacific Garbage Patch...

It is a gyre of Marine litter twice the size of France situated off the coast of California that is estimated to contain 100 million tonnes of waste, predominantly plastic. In 2009 the ocean was said to have 46,000 pieces of plastic per squre kilometre of ocean which out weighs the amount of Plankton by the ratio 6:1.The great Pacific patch is the largest landfill site in the world although there are other Garbage patches, most notably in the North Atlantic and the Indian Ocean.

How did it get there?

The plastic has travelled far and wide down streams and rivers finally entering the ocean where the waste accumuates into one large landfill site. Additional to land pollution of plastic, other sources include commercial fishing, recreational boaters, merchant military vessells and offshore oil and gas platforms.

 http://news.discovery.com/videos/earth-whats-an-ocean-garbage-patch.html

What are the main affects on the environment?

The largest effect of the garbage patches in the ocean is to the marine life. Although it is widely accepted that plastic itself is not toxic, it attracts and allows other harmful chemicals to accumulate such as PCB and DDT. These chemicals in high levels are dangerous to most species of animals.

"Worldwide, according to the United Nations Environment Programme, plastic is killing a million seabirds a year, and 100,000 marine mammals and turtles."

Although chemical pollutants are dangerous the main cause of death is entanglement in the plastic waste or swallowing and thus choking on plastic particles. The larger pieces of plastic can cause the entanglement however it is the smaller pieces which can be swallowed. Plastic is not biodegradable however, it can be photodegraded. This breaks down larger pieces of plastic in smaller particles which then remain in the ocean.

What can be done to help?

There are many ongoing relief efforts which are aimed at recovering large amounts of plastic from the oceans. There are also quite a few charities which are commited to helping clean up the garbage patches.

One charity which appears quite influential from the research i have carried out is http://www.5gyres.org/

The main mission of the charity is outlined below:

"To conduct research and communicate about the global impact of plastic pollution in the world’s oceans and employ strategies to eliminate the accumulation of plastic pollution in the 5 subtropical gyres."

This is just a small example of how humans can impact the environment on a grand scale with the consequences of human actions irrevocable.  Although this does stray away from the topic of weather slightly i do think its important to look at this topic in broad terms.

Classroom tasks
This is a difficult issue to tackle with the human race so accustomed to using plastic as the predominant packaging material. One task could students working together in groups to think of ways the "garbage patch" phenomena can be avoided in the future and also how best to tackle the current issue of waste in the oceans.

Another question to pose could be whether they think its acceptable to use to oceans in such a way. This could be a good linking question as can be made relevent to alot of geographical concepts such as space, place and population