The Plastic Menace

05 Jul 2017
The Plastic Menace

Unrecycled plastic waste is carried to the oceans – and stays there

This is not the first time that I'm quoting Prince Charles on this page, and I'm not doing it for being a special fan of the British royalty, but because I find him again and again a champion for the nature in general and our oceans in particular.

Recently, the Prince of Wales said: “I find it sobering to think that almost all the plastic ever produced is still here somewhere on the planet in one form or another and will remain here for centuries to come, possibly thousands of years.”

What is happening now is that the issue of plastics described by the Prince of Wales, with due English understatement, as 'sobering', can be safely labelled alarming, especially with respect to marine environment. Plastics are one of the most useful materials invented and applied by humanity. They're long-lasting, convenient and versatile in use and increasingly used in more and more production sectors. In fisheries, we employ them in fishing nets and ropes made of synthetic fibres, and in various implements; floats, buoys, and diverse containers.

So far, so good. So why have plastics become recently and repeatedly a fisheries-relevant concern? It appears that their unchecked disposal into the marine environment on an unprecedented scale is resulting in significant global impacts on marine and other related wildlife.

For example, according to one study: "of the 275 million tonnes of plastic waste generated by 192 countries in 2010, 4.8–12.7 million tonnes could have entered the ocean." 

Plastic objects of diverse shapes and sizes may end up both on beaches and in the oceans. Some of the large items, such as discarded fishing equipment or items from shipping containers, are lost into the sea directly, whereas items discarded on land can be carried along brooks and rivers to the sea. Also, inadequately managed, slow to degrade and unrecycled plastic waste, produced in countries with long coastlines, is only too often left to work its way into the oceans.

Plastics that spend considerable time in the sea gradually disintegrate until they turn into so-called microplastics. Typically less than 5mm in size, microplastics can be eroded to particles as small as 1–100nm – i.e., nanoplastics. These particles in many cases start out as large plastic pieces, slowly eroded by water; others start off as microplastics specifically produced for certain uses, such as the microbeads in facewash, soaps and shower creams. Microbeads are stable, easily evade filtration systems at water treatment plants, and are discharged directly into the oceans. In any case, their small size fools various organisms into taking them for edible particles, which brings them eventually into the fishes' and our own food chain.

The UK alone produces every year some 680 tonnes of plastic microbeads for cosmetic products, and it is only a small fraction (0.01–4.1%) of the estimated total level of microplastics in the ocean. However, the cosmetic industry has lately recognised that this contribution to marine pollution can be avoided. Chris Flower, director-general of the Cosmetic Toiletry and Perfumery Association, recently said that "although science has shown the use of microbeads in cosmetics is but a minor contributor to the global problem of marine microplastic contamination, nevertheless our industry has acted responsibly to phase out the use of microbeads in wash-off products where the microbeads go down the drain and may end up in the seas."

Although it is relatively easy to develop policies and bans for microbeads and microfibres, these sources are just a drop in the ocean in terms of tonnage. Instead, poor land-based waste management practices are seen by the United Nations as the major source of marine microplastics pollution and given the nature of the oceans’ geography, it's a global and multifaceted problem. The oceans’ powerful currents carry plastic waste great distances, so that waste from one place can become an issue in a region geographically distant from its origin. Large items tend to float and are carried for many thousands of miles on the surface of the ocean as documented by software engineer David Fuchs and Erik van Sebille from Imperial College in London.

Then there are the gyres - large swirling regions of oceanic water where plastics accumulate, the largest and most famous of which being the Great Pacific Garbage Patch. Another revolves in the North Atlantic. Those gyres represent enormous traps, for anything that floats and in this or other manner finds its way into their neighbourhood, is attracted towards their centres and destined to keep floating around.

According to some estimates, there are more than five trillion microplastic particles in the world's oceans, and the equivalent of one rubbish truck of plastic waste is being added to the sea every minute. At the present rate of plastic production, by 2050 that will increase to four trucks every minute. The plastic in the ocean will take decades or even centuries to break down into macro and micro particles, but the prevailing opinion is that in spite of the oceanic dynamics it will never completely disappear.

But, that's not all. Another source of marine microplastics coming from household wastewater are the micro-fibres leaching from clothing when washed. Micro-fibres are a hundredth of the diameter of a human hair and are used for better waterproofing, breathability and flexibility in sportswear. The most common types of microfibres are made from synthetics, such as polyesters and polyamides, and according to researchers giving evidence to the UK House of Commons Environmental Audit Committee in 2016, the number of leached micro-fibres in wastewater could be as many as 1900 per garment.

Projections, unfortunately, are not optimistic, and gloomy are also the present realities. Remedies anybody?