Garbage Patch In The Oceans
When someone uses the term garbage patch, do not mistake him or her as referring to just another patch of garbage on land.
He or she is very likely to be referring to specific patches of garbage that have built up in our oceans, such as the Pacific Gyre or the Great Pacific Garbage-Patch, the Indian Ocean Garbage-Patch, or the North Atlantic Garbage-Patch. These garbage build-ups in the different parts of our oceans have specific names, based on the ocean in which they are found.
What’s so special about these garbage patches
I was very shocked when I first found out about the scale of garbage buildups in the oceans. The waste patches in the oceans sprawl across large distances (i.e. hundreds of kilometers) of oceanic waters and can go as deep as 100 feet or more. And within each patch, abnormally high concentrations of plastic and other garbage debris are found.
According to water pollution facts from the National Geographic, the Great Pacific Garbage Patch holds as many as 750,000 bits of plastic per square kilometer. In fact, these oceanic garbage-patches form the world’s largest rubbish dumps, even larger than those you find on the land.
But unlike the garbage dumps on land, the garbage debris in these oceanic patches do not form a solid, compact or continuous garbage pile. Instead, the debris are diffused over large distances of water surface, as well as suspended throughout the water columns (with higher concentrations in the upper column). Expeditions by Project Kaisei confirmed that the debris mainly comprised small pieces of plastics, which increased in concentration the closer one gets to the centre of the gyre. As described by Michael J. Moore, racing boat captain and oceanographer who “discovered” the Great Pacific Garbage Patch, the patch is like a “plastic soup”.
The Great Pacific Garbage Patch was predicted in a 1988 paper published by the U.S. National Oceanic and Atmospheric Administration (NOAA), based on several measurement studies between 1985 and 1988 on neustonic plastic in the North Pacific Ocean. However, the garbage-filled patch was only “discovered” in 1997, when Moore crossed the Pacific Ocean after having competed in the Transpacific Yacht Race.
According to Wikipedia, the Great Pacific Garbage Patch is located somewhere between 135° to 155°W and 35°N to 42°N. Different estimates of the size of the Great Pacific patch have been made – some claim that the patch is larger than the continental United States, others claim that it is twice the size of Texas. Most recently, there are new claims that the patch might only be about 1% or less than the size of Texas.
As you can see, it is not easy to determine the size of a garbage patch, especially since it is defined as an area of water where the concentration of plastic debris in the upper water column is substantially higher than average. Firstly, no specific standards have been set as to what is considered “higher concentrations”. Moreover, the debris also drifts. So there is really no clear cut boundary where the patch starts or end.
Most of the plastic debris in the patches is also suspended in the water or just below the water surface. Because of the diffused nature of the patches, they are neither visible in satellite photography nor detectable by aircraft. In fact, some of the debris might not even be visible from a boat deck. The size of the various patches is now estimated mainly by sampling the water for concentration of debris at different points of the respective oceans.
According to Wikipedia, the North Atlantic Garbage Patch was first mentioned in writing in 1972 , and is estimated to be hundreds of kilometers across in the North Atlantic Gyre. According to the National Oceanic and Atmospheric Administration, this patch shifts seasonally, and substantially too – as much as 1600 km northward and southward, and even more during the El Nino events. In turn, the Indian Ocean Garbage Patch was discovered in 2010 and is found in the central Indian Ocean.
Watch this video on the garbage patch.
Where does the garbage come from
According to the UNEP, refuse from land-based activities account for 80% of the rubbish that enters the garbage patch, while off-shore activities account for the remaining 20%. These sources of garbage in the sea can be categorized into
- (i) tourism related litter on the beach,
- (ii) storm run-off (which carries litter from the streets and even sewer overflow, etc) pollution
- (iii) fishing related water pollution (e.g. illegal dumping of fishing nets or lines, etc)
- (iv) discharge of garbage and sewage into sea from boats, ships and other vessels.
It appears that developed and industrialized countries produce larger quantities of non-organic waste like plastics and synthetics, as compared to their developing or rural communities. However, as some of the latter less developed countries also start on the industrialization path, they too will be producing more of the non-organic waste, and adding to the volume of non-biodegradable waste materials on this earth.
As cited in the Discover magazine, Marcus Eriksen from Algalita, a marine research foundation, observed a link between the amount of plastic produced and the amount of plastic debris found in the oceans. The increase in plastic debris in the Great Pacific Garbage Patch from 0.002g per square meter in 1999, to 0.004g per square meter in 2005, took place during the same period where the American Chemistry Council in Arlington, Virginia, had indicated the doubling of plastic production in North America alone.
Remember what I mentioned about how a garbage patch is being identified? I said that it is defined as an area with exceptionally high concentration of plastic debris (and other debris).
You might be wondering why the specific mention of plastic. Surely, the garbage patches aren’t just contaminated by plastic right?
Well, while the rubbish that enters the seas and oceans are indeed more than just plastic, it is the plastic debris (including Styrofoam) that persists after years and years, suspended in the water column, while the other materials either biodegrade with time, or sink to the bottom of the ocean and gets forgotten.
Plastics do not biodegrade, but simply break down into smaller pieces under the sun via a process known as photo-degradation. In this way, massive amounts of plastic debris accumulate in the garbage patches. In fact, according to Moore’s research, in the some parts of the Great Pacific Garbage Patch, the proportion of plastic to surface zooplankton is 6:1.
How does the garbage get there
If most of the rubbish in the garbage patches came from inland activities, how did they end up in the middle of our oceans?
This is what happened, and is still happening.
The garbage that ends up in the seas are swept by oceanic currents and winds into what are known as oceanic gyres. A gyre is a large system of rotating ocean currents, often accompanied by large winds. The gyre is actually a vortex, or a spinning flow of oceanic waters around an epicentre.
The rotating flow of water within the gyre draws in garbage from the surrounding waters and prevents the garbage debris from leaving the vortex. At the same time, the surface water currents, driven by winds in the gyre, gradually moves the suspended or floating debris toward the relatively low-energy centre of the gyre. It is at this epicenter that the various garbage patches are found.
There are 5 main gyres in our oceans. For example, the Great Pacific Garbage Patch is located in the middle of the North Pacific Gyre, while the North Atlantic Garbage-Patch is found in the North Atlantic Gyre and the Indian Ocean Garbage-Patch is found in the Indian Ocean Gyre.
According to Moore, garbage coming from Asia would take about one year to reach the Great Pacific Garbage Patch, while garbage from the United States would take several years.
What’s the problem
There might be some people who wonder what is so problematic about having garbage dumps in the sea. After all, we get land pollution when we dispose of rubbish in landfills, while we pollute the air when we incinerate our rubbish. Our oceans are so vast, we won’t be able to use all of it – won’t they make good places for mankind to dispose of massive amounts of waste?
Well, the answer is no. Oceans are not good dumping ground for rubbish. And I’m saying this not only for the various forms of life in the sea, but also for Man who is living on land.
Let’s touch on the effects of the garbage dumping on life in the seas and oceans first. The garbage in the oceanic patches, especially plastic ones, poses danger to the lives of marine creatures in the seas and oceans.
Firstly, many fishes, turtles and other marine creatures often mistake the small pieces of plastic debris as food and ingest them. The marine creatures often end up “full”, but actually undernourished or starved, as the plastic pieces do not provide any nutrition. In many cases, the plastic debris block the digestive or respiratory systems of the marine creatures, and they eventually starve or suffocate to death.
According to ScienceDaily, a team of graduate students from the Scripps Institution of Oceanography, UC San Diego, found plastic debris in more than 9% of the fish the team collected during its voyage to the Great Pacific Garbage Patch. However, according to one of the graduate students, Peter Davison, this figure is likely to be underestimate of the true ingestion rate because some fishes could have regurgitated or passed out the plastic pieces, while many others could have died ingesting the debris.
Secondly, the marine creatures may also be entangled in unwanted and unmanned fishing nets, leading to what is known as “ghost fising”. The marine creatures caught in these nets are restricted in movement – many of them eventually starve to death. Others die of infections from the wounds caused by the nets, while some of the “caught” creatures that need to surface above water to breathe suffocate to death.
According to GreenPeace, an estimate is made that more than 1 million sea birds and 100,000 sea mammals and turtles die from the ingestion of plastic or entanglement in discarded fishing nets or debris.
Besides chocking the marine creatures in the oceans, a large proportion of the plastic debris also sinks to the bottom of the sea. These debris often smoother the oceanic beds, and kill the marine creatures found at the bottom of the oceans. According to GreenPeace, several dutch scientists have found more than a hundred pieces of litter on every square kilometer of oceanic bed within the Pacific Garbage Patch.
Now, let’s look at the effects of the garbage dump on Man.
According to CNN in 2008, at least 1 billion people on this planet consume fish as their main protein source, while 2.6 billon obtain at least 20% of our animal protein from fish. This means that when our fishes are polluted and unhealthy, Man too will suffer.
According to Wikipedia, plastic contain toxic additives, some of which have been added to the polymers during the production process, to give the specific plastic type its desired property. Some of these additives include plasticizers like phthalates, which have been found to lead to organ damage in animals and reproductive problems in humans. When these toxic chemicals leech from the plastic debris stuck in the bodies of the fishes that consume them, the chemicals may interfere with the reproductive function of the fishes. At other times, the toxic chemicals bio-accumulate in the bodies of the fishes, and when these fishes are consumed by humans, humans are in turn harmed.
According to Peter Davison and his team-mates from the Scripps Institution of Oceanography, UC San Diego, it is estimated that plastic is being ingested by fish in the North Pacific found in the intermediate depths at a rate of about 12 to 24 thousand tons yearly.
The plastic ingested by the fish are also highly absorbent of toxic hydrophobic pollutants like PCBs, DDT (a pesticide) or PAHs. When the fishes consume these contaminated plastics, and we consume the fish, the toxic chemicals bioaccumulate and biomagnify in us – bringing us a whole range of health problems down the line.
Studies are currently being made by various parties (e.g. Project Kaisei) on the feasibility of cleaning up the plastic debris in the various oceanic garbage patch. Any attempt to clean up the mess will be a complicated one – the process of clean up needs to minimize harm to marine creatures and the marine ecology, as well as be cost and energy efficient.
Some of the suggested methods being explored include the use of floating receptacles placed close to areas of high debris concentrations to “collect” big pieces of debris as they drift in the water, as well as the trawling of fishing nets over the area to trap the debris.
Nonetheless, Angelicque White, scientist from the Oregon State University, cautioned that the removal of plastic debris from the oceans may also remove marine life, such as phytoplankton, zooplankton, and other small surface-dwelling marine creatures from the waters, as such upsetting the ecology in that area.
In fact, the sentiment is mixed over whether attempts to clean up the oceans would be futile.
Nonetheless, those who have been studying the conditions at the various garbage patches, including Moore, White and Jackie Savitz (campaign director for Oceana, an ocean advocacy group), said one thing in common – the one important thing that can and need to be done – now – is to stop any more debris from entering the oceanic waters.
A multi-prong effort would be required
- educating the shipping and fishing industry (including ship owners and operators, offshore platforms, fishing boat operators), as well as other related industries, on the consequences of irresponsibly dumping garbage into the seas
- imposing penalties for deliberate and intentional disposal of garbage (including littering) at sea
- getting the world community to reduce their use of plastic
- replacing conventional non-biodegradable petroleum plastics with biodegradable bio-“plastics” (such as those made from corn or starch)
- collect debris that gets washed up onto beaches for proper disposal.
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