The Great Pacific Garbage Patch
S VISHNU
The Great Pacific Garbage Patch or the pacific trash vortex is a collection of marine debris (litter that ends up in the ocean, seas, and other large bodies of water) in the North Pacific Ocean. It includes two distinct collections of debris which are formed due to the North Pacific Subtropical Gyre.
The Great Pacific Patch comprises of waters from the West Coast of North America to Japan. The patch incudes the Western Garbage Patch(near Japan), and the Eastern Garbage Patch(between Hawaii and California).
These areas of debris are connected together by the North Pacific Subtropical Convergence Zone. In this zone the warm water from the South Pacific meets up with cooler water from the Arctic and acts as a pathway that moves debris from one patch to another.
The North Pacific Subtropical Gyre (Gyre is a large system of ocean currents) is formed by four currents which include the California current, the North Equatorial current, the Kuroshio current, and the North Pacific current. The centre of a gyre is often very calm and stable. The circular motion of the gyre moves the debris into the centre of the gyre where it gets trapped.
Debris accumulates in the Great Pacific Garbage Patch because most of the debris is not biodegradable. Many plastics don’t wear down; they simply break into smaller and smaller pieces. For many people, the concept of a “garbage patch” conjures up pictures of an island of trash floating on the ocean. Originally these patches are entirely made up of tiny bits of plastics that are not always seen by the naked eye. These are called microplastics.
What we know?
The microplastics of the Great Pacific Garbage Patch makes it look like a cloudy mass of water. This cloudy mass is intermixed with larger items which are discarded in the ocean. The seafloor beneath the Great Pacific Garbage Patch is an underwater trash heap. Scientists recently discovered that about 70 to 75 per cent of the debris sink to the bottom of the ocean floor.
Scientists earlier predicted the existence of the Great Pacific garbage Patch but it was a racing boat captain by the name of Charles Moore who actually discovered the patch and the vortex that accumulated the trash. Moore was sailing to California by crossing the North Pacific Subtropical Gyre. Moore noticed millions of pieces of plastic surrounding his ship.
About 80 percent of plastic in the ocean comes from land-based sources while the remaining 20 percent comes from ships, boats and other marine sources. Studies show that nearly half the mass of the Great Pacific Garbage Patch was made up of synthetic fishing nets which was due to increased fishing activity in the Pacific Ocean. Even though different types of trash enter the ocean, plastics make up the majority. This is because plastic is durable, malleable and its cost is low which makes it suitable for manufacture of consumer and industrial products.
Another reason is because plastic goods do not degrade completely. It simply breaks down into smaller pieces. The sun breaks down these plastics into tinier pieces and this process known as photodegradation. Most of this debris comes from plastic bags, bottle caps, plastic bottles, and Styrofoam.
How does the Debris Affect Marine Life?
Marine debris are very harmful to marine life. For instance, sea turtles often mistake plastic bags for jelly fish which is their favourite food. Albatrosses get confused by plastic resin pellets for fish eggs and feed them to chicks, which die of starvation or ruptured organs. Seals and other marine mammals are especially at risk as they get entangled in abandoned fishing nets which are discarded in the ocean. These animals often drown in these fishing nets. This phenomenon is known as Ghost Fishing.
Plastic debris leach out and also absorb harmful pollutants which can enter the food chain when consumed by marine life. The microplastics and other trash collected on the surface of the ocean can block the sunlight from reaching the algae and plankton below which can affect their survival which in turn can cause change in the food web. Hence Fishes and turtles will have less food since they feed on algae and plankton. If populations of these animals decrease then there will be less food for such as tuna, sharks, and whales which are higher in the food chain. This will eventually lead to shortage of seafood and can cause drastic increase in seafood cost.
How do you prevent the Garbage patch from getting bigger?
The Great Pacific Garbage Patch is far away from the shoreline of any country. So taking up responsibility and providing funding to initiate a mission to clean up the patch is not feasible for any country. To initiate such a large scale operation to clean up the patch would bankrupt any country. Even if we could design special nets to collect the debris, the size of the ocean would make it far too time consuming.
Scientists and environmentalists agree that limiting and eventually eliminating the use of single use plastic is a step in the right direction to reducing the debris that enter the ocean. Another productive way to clean up the patch is to increase the use of biodegradable resources. This can be done by use social media and direct action campaigns to support and promote businesses and manufacturers that involve in production of biodegradable and reusable materials.
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