More than five trillion pieces of plastic, collectively weighing nearly 269,000 tons, are floating in the world’s oceans and causing damage throughout the food chain, according to new research by the 5 Gyres Institute — but that is apparently a drop in the bucket compared to the amount littering the ocean floor.
Data collected by scientists from the United States, France, Chile, Australia and New Zealand estimates a minimum of 5.25 trillion plastic particles in the oceans, most of them “microplastics,” measuring less than 5mm.
Microplastic pollution is found in varying concentrations throughout the oceans, but until now estimates of the global abundance and weight of floating plastics, both micro- and macroplastic, have lacked sufficient data to support them. To better estimate the amount of plastic particles and their weight floating in the world's oceans, the researchers contributed data from 24 expeditions collected from 2007-2013 across the Atlantic, Pacific and Indian Oceans, coastal Australia, the Bay of Bengal and the Mediterranean Sea. The data included information about microplastics collected using nets and large plastic debris from visual surveys, which were then used to calibrate an ocean model of plastic distribution.
Marine plastic, which the researchers contend amounts to 268,940 tons, is largely made up of clothing, food and drink packaging, plastic bags and abandoned fishing gear. Large pieces of plastic can strangle animals such as seals, while smaller pieces are ingested by fish and then fed all the way up the food chain — a problem due to the chemicals contained within plastics, as well as the pollutants that they absorb once in the marine environment.
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While spread out around the globe, much of this waste accumulates in five large ocean gyres — circular currents that churn up plastics into a particular area. Each of the major oceans has plastic-filled gyres, the most well-known being the ‘great Pacific garbage patch’ that covers an area roughly equivalent to Texas.
"Our findings show that the garbage patches in the middle of the five subtropical gyres are not the final resting places for the world's floating plastic trash. The endgame for micro-plastic is interactions with entire ocean ecosystems," says 5 Gyres Institute’s Marcus Eriksen, who led the study published in the scientific journal PLOS ONE.
“There's much more plastic pollution out there than recent estimates suggest.” Eriksen added. “It's everything you can imagine made of plastic — it's like Walmart or Target set afloat."
The research found that the gyres themselves are likely to contribute to the problem, acting as “shredders” to the plastic before dispersing it, and that the volume will likely increase due to the continued rampant production of throwaway plastic, with only 5 percent currently recycled.
While this volume of plastic may be hard to wrap your head around, scientists have long thought that the number should be much, much higher, considering the rate at which we continue to produce it. A second study, published this week in Royal Society Open Science, set about tracking down the rest of the plastic in the oceans – the hundreds of thousands of tons of “missing” plastic that has sunk to the sea floor.
Scientists from the Natural History Museum in London, the University of Barcelona, the University of Oxford, the Scottish Association for Marine Science and Plymouth University analyzed deep-sea sediment and coral from the Atlantic and Indian Oceans and the Mediterranean Sea between September 2001 and August 2012, have found for the first time a “ubiquitous contamination” of microplastics in the deep sea — four orders of magnitude greater (yes, 10,000 times greater) than the amount floating in shallow and coastal waters. Polyester, polyamides, acetate, acrylic and rayon — which made up more than 50 percent of the particles — were the most abundant. The teams estimate that there are four billion fibers per square kilometer in Indian Ocean sediments alone.
"The puzzle for marine scientists has been to establish where plastic debris is going. Part of the answer is that much of this waste is breaking down into fibres invisible to the naked eye and sinking to the sea floor," said Dr Lucy Woodall, zoologist at the Natural History Museum. "It is alarming to find such high levels of contamination, especially when the full effect of these plastics on the delicate balance of deep sea ecosystems is unknown."
Plastic pollution as a whole has risen to the forefront of issues that big business must do its part to mitigate. In June, the Plastic Disclosure Project (PDP), the UN Environment Programme and natural capital analysts Trucost released research that illustrated the irrefutable need for companies to improve the way they measure, manage and report the amount of plastic they use in their business operations and supply chains. While more and more companies are harvesting ocean plastic and upcycling it into products ranging from scuba gear to carpet to skateboards, and companies such as J&J and Unilever have committed to eliminating plastic microbeads from their beauty products, a sea change is needed to reverse the damage we continue to do to the oceans.