When you hear people talk about the great garbage patches that have accumulated in our oceans, the image conjured in your mind may well be giant piles of waste containing discarded wrappers and bottles and so on, floating on the surface of the water, but in reality this is not necessarily the case.
These great garbage patches consist of large quantities of marine debris, most of which is plastic. This highly durable material, which surrounds us in our everyday lives due to its low cost and durability, sadly poses great risks to our environment and ecosystems when it does not decompose leading up to massive ocean waste.
The Great Pacific Garbage Patch
Perhaps the most famous of these patches of waste is the Great Pacific Garbage Patch, a huge area, located in the North Pacific Ocean that stretches from the west coast of North America, all the way to Japan. This giant patch is distinguished in two parts; the Eastern Garbage Patch, lies between Hawaii and California, and the Western Garbage Patch, is close to Japan.
This vast patch of waste is centred within a subtropical gyre. The gyre forms a system of ocean currents that move in a circular motion, in response to a combination of the force created by the rotation of the planet and wind. It is this circular motion that draws waste into the centre of the gyre, where it becomes trapped and breaks down into little pieces. Gradually, many of these tiny particles of plastic release from the gyre to float around in the sea and eventually wash up onto beaches.
First Spotted In 1997
Sailor Charles Moore first noticed this particular expanse of debris, during a trip across the North Pacific in 1997, when he noticed masses of tiny particles of plastic surrounding his boat. He had no idea at that time that the area was impacted with waste to the extent that it is.
It is thought that there is now somewhere in the region of 100 million tonnes of waste trapped in this location in the currents of the North Pacific Gyre. On a recent trip in 2014 to reassess the scale of the issue, Charles Moore and his team discovered that the problem had grown significantly worse and noted that some of the more permanent accumulations of plastic were more than 15 meters long.
The fact that the patch lays several hundred kilometres away from any coastline has meant that it is easy for those countries closest to it to refuse to take responsibility for funding or planning an ocean clean up.
These patches do of course contain some large items of waste, but they mostly contain tiny particles of plastic. The durability of this material means that it is partially broken down in the sun, thanks to a process called photo degradation, but unable to completely biodegrade. Plastic that finds its way into the ocean after being discarded irresponsibly can take anything from 500 to 1000 years to completely break down. Until this long process completes, the remaining tiny pieces of plastic, (micro plastics) remain in the water, harming the environment.
To the naked eye, many of these patches are not always visible, as the micro plastics simply tend to make the water look cloudy. Even the Great Pacific Garbage Patch is not actually visible on satellite imagery. However, when the water is still and calm, more waste is visible, because it floats to the surface.
The plastics found in the Great Pacific Garbage Patch primarily come from fishing nets, plastic bags, plastic water bottles and disposable Styrofoam cups and trays. The majority of this waste originates from North America, Japan and Asia.
The Scale Of The Issue
It is very difficult to tell just how much waste is in the Great Pacific Garbage Patch, particularly as it is now thought that up to 70% of the plastic sinks to the bottom of the ocean creating additional pollution way beneath the surface of the water. It is estimated that the weight of the rubbish in this patch weighs in the region of 100 million tonnes.
This large-scale environmental catastrophe is damaging our environment and ecosystems in several ways:
Is A Clean Up Possible?
A variety of individuals and organisations are dedicated to cleaning up this man made environmental disaster, despite the fact that over the years it has generally been deemed impossible due to its scale. Recently there have been some exciting and innovative approaches to the removal of this waste from our oceans and there will be more about this in next week’s blog.
The only way to prevent the problem from growing in the mean time is to reduce our dependence on plastics, instead turning to biodegradable, non-toxic alternatives. Secondly, we need to get to the root of the problem by making sure that waste materials we use both on land and on the oceans themselves no longer enter the water but are dealt with responsibly and sustainably.