- 80,000 tonnes of plastic floats in the Great Pacific Garbage Patch
- Discarded fishing nets make up almost half the 80,000 tonnes of garbage
- Great Pacific Garbage Patch now three times the size of France: Study
New Delhi: Many of us might have seen the photograph of a seahorse latched onto a cotton swab, showing the ‘heartbreaking’ state of our polluted oceans. It’s just one small example of how prevalent plastic debris is in the ocean. According to a recent report published in the journal Scientific Reports, over 1.8 trillion pieces of plastic weighing 80,000 tonnes, which is equivalent to 500 jumbo jets, are currently afloat in an area known as the Great Pacific Garbage Patch – and it is rapidly getting worse as people are continuously littering the seas. The report shows that plastic waste, broken down into smaller pieces (microplastics – plastic pieces less than 5 millimeters long) is everywhere, right in the lower depths of the sea floor killing corals and floating on the surface and is mistakenly eaten by marine animals and birds.
The figure of 1.8 trillion plastic pieces floating in the Great Pacific Garbage Patch is actually the main conclusion of a three-year mapping effort conducted by an international team of scientists affiliated with The Ocean Cleanup Foundation, six universities from New Zealand, United States, Britain, France, Germany, Denmark, along with an aerial sensor company.
Where is the Great Pacific Garbage Patch Located
Located halfway between Hawaii and California, the Great Pacific Garbage Patch (GPGP) is the largest accumulation zone for ocean plastics on Earth. It occupies an area three times the size of France. As per the findings, the discarded fishing nets make up almost half the 80,000 tonnes of the floating garbage, and researchers believe that around 20 percent of the total volume of trash is debris from the 2011 Japanese tsunami. The study also suggested that plastic traveled to the Great Pacific Garbage Patch from elsewhere, riding the ocean currents.
How have the researchers quantified the floating plastic problem
The researchers initially used single, fine-meshed nets, typically less than a meter in size in the Great Pacific Garbage Patch to quantify the floating plastic problem. Since this method covered smaller area and didn’t help measure the magnitude of the problem to its fullest extent, the researchers then went on to do a comprehensive sampling of the GPGP. They crossed the debris field with 30 vessels simultaneously, supplemented by two aircraft surveys. Although most vessels were equipped with standard surface sampling nets, the fleet’s mothership RV Ocean Starr also trawled two six-meter-wide devices, which allowed the team to sample medium to large-sized objects.
In an effort to increase the surface area surveyed, and quantify the largest pieces of plastic – objects that include discarded fishing nets several meters in size – a C-130 Hercules aircraft was fitted with advanced sensors to collect multispectral imagery and 3D scans of the ocean garbage. The fleet collected a total of 1.2 million plastic samples, while the aerial sensors scanned more than 300 square kilometer of ocean surface.
According to the surveyors who also used two planes to assess the ocean pollution, the amount of plastic found in this area, known as the Great Pacific Garbage Patch, is “increasing exponentially”.
We wanted to have a clear, precise picture of what the patch looked like, said Laurent Lebreton, the lead oceanographer for the Ocean Cleanup Foundation and the lead author of the study.
The new survey estimates that the mass of plastic contained there is four to 16 times larger than previously supposed, and it is continuing to accumulate because of ocean currents and careless humans both onshore and offshore, he further said.
“We were surprised by the amount of large plastic objects we encountered”, said Dr. Julia Reisser, Chief Scientist of the expeditions. “We used to think most of the debris consists of small fragments, but this new analysis shines a new light on the scope of the debris,” she added.
It was also observed that the large debris matter breaks down into smaller plastics (microplastics) while floating in the GPGP and due to temperature changes. The microplastics then floats within the water surface layers, in the water column and as far down as the ocean floor, and are often mistaken for food by marine animals.
Speaking to NDTV about how marine animals interact with plastic debris, the researcher said that marine life consumes microplastics, which partially break down in their body’s into toxic waste which threatens biodiversity in the oceans. “Fish that are not killed might end up in our food chain, which means ocean microplastic is not only a problem for the animals directly in contact with plastic, it finds its way all across the world,” the researcher added.
When asked about how the human waste is reaching places where it was never intended to be, like in the case of Great Pacific Garbage Patch, the researcher explained that everything that is thrown on the street or incorrectly thrown away ends up in water streams and thus, the ocean. When in the ocean, streams take the plastic to central gyres (large system of circulating ocean currents) which continue to collect plastics.
The study also warns that not only does plastic pollution in the Great Pacific Garbage Patch pose risks for the safety and health of marine animals, but there are health and economic implications for humans as well.
Efforts to clean and eradicate ocean plastic have also caused significant financial burdens. The United Nations reported in 2014 that the approximate environmental damage caused by plastic to marine ecosystems represents $13 billion USD. This figure included the cost of beach cleanups and the financial loss incurred by fisheries.
When asked about what efforts are being taken by the government and other oganisations to clean up this plastic menace, the Ocean Cleanup Foundation said, “To solve the problem, we need to understand it first. Substantial international measures should be implemented in the coming decade to stop the increasing inflow of plastic waste into our ocean; and by supporting removal initiatives, such as coastal and ocean cleanups, for the existing mess accumulating in the environment since the introduction of plastic in our societies. Also, the governments across the globe have been very supportive of our projects that support the cleaning efforts through funds and means.” The Ocean Cleanup has pledged to clean up half of the Great Pacific garbage patch within five years and mop up the other rubbish-strewn gyres (circulating ocean currents) by 2040.