Is the Ocean turning into a Plastic Soup?

This was first published in the TRINet blog, part of the TRINet newsletter for March 2011

Map showing ocean gyres where floating garbage accumulates

The ocean has become a repository of most of the waste humans generate. Every year, a large amount of plastic debris that enters the oceans releases persistent bio-accumulating and toxic compounds into the sea. Most of the plastic in our oceans is buoyant and lightweight so they get transported by ocean currents and gather in convergence zones in the sea. These zones have been called ocean landfills, garbage patches and even plastic soup by the media and environmental activists. Though this accumulation of plastic is visible and an indicator of the larger issue of marine litter, a majority of the plastic polluting the sea are small fragments that are not visible and hence not detected by satellite imagery for monitoring and studying.

It is almost impossible to quantify the exact amount of plastic debris that enters the oceans but land based sources of these inputs include poorly managed landfills, riverine transport, untreated sewage and storm water discharges, wind-blown debris, industrial and manufacturing facilities with inadequate controls, recreational use of coastal areas and tourist activities. In general, more litter is found near areas of thick human populations and consist mainly of consumer plastic items like bottles, shopping bags and personal hygiene products. Offshore sources of plastic pollution include fishing and recreation vessels, cruise liners, merchant shipping, oil and gas platforms and aquaculture facilities.

Studies have shown that plastic production had a steady growth rate since the 1950s till 2008 where the economic downturn saw a drop in 25% of production.

It’s not only the surface of the ocean that has plastic accumulating. The Census of Marine Life program, completed in 2010, reported finding plastic debris at abyssal depths. Plastics at these depths will take much longer to fragment due to lack of ultraviolet (UV) penetration and much colder water temperatures.

Plastics have also found their way into the stomachs of seabirds that feed offshore. Studies have shown that in the 1980s, industrial plastic found in stranded birds peaked, and in the 1990s, consumer plastics in stomachs of birds tripled and then decreased. Smaller fragments of plastic in the sea will increase chances of ingestion by birds and marine life while larger debris will trap and entangle them.  

The social and economic cost incurred by plastic pollution is always borne by the affected rather than those responsible for the pollution. The most obvious economic impacts of plastic debris are on fishing boats – fouled propellers, removing plastic debris from nets and blocked engine water intakes bring about losses in fishing opportunities.

Cleaning up of beaches and waterways can also be quite expensive. In the Netherlands and Belgium, approximately US$13.65 million per year is spent on removing beach litter. Cleanup costs for municipalities in the United Kingdom have increased by 38 per cent over the last ten years, to approximately US$23.62 million annually. It is estimated that removing litter from South Africa’s wastewater streams effectively would cost about US$279 million per year.

The Global Program of Action (GPA) for the Protection of the Marine Environment from Land based Activities, whose Secretariat is provided by UNEP, is the only global initiative that directly addresses the link between watersheds, coastal waters and the open ocean. Activities have included collaboration with the Ocean Conservancy’s International Coastal Cleanup (ICC) to raise awareness of the marine debris issue in regions and to encourage greater public education and engagement. The 18 Regional Seas Conventions and Action Plans could serve as platforms for developing common regional strategies and promoting synergies, mainly at the national level, to prevent, reduce and remove marine litter.

Despite all efforts to curtail littering of the oceans and water bodies, the problem of plastic and other pollution still persists. 

Not only the oceans but even backwaters and rivers are also affected. A study on the sources of pollution of Vembanad Lake in Kerala has shown that plastics and inorganic waste dumped from houseboats is third on the list of sources of inorganic pollution, after effluents from nearby factories, and emissions, oil leaks from motor boats.

Developed countries have managed to curtail land based sources of plastic pollution quite effectively but developing countries like India are still far behind. Annie George, CEO, BEDROC, feels this will continue till a critical level of industrialisation is achieved by developing countries and then, gradually, the incomes accrued will be channeled to improving efficiencies and pollution control measures. If we accept this logic, she adds, then we need to be thinking about ring fencing traditional livelihoods and take urgent measures to safeguard our rivers and other water bodies too.

Chennai based Dr. Ahana Lakshmi, who has a PhD in environmental science, also feels our fresh water resources and backwaters are more critical and sensitive to pollutants than the sea. Water for drinking, industries and agriculture is provided by these water bodies and if they are polluted, then we have more to lose, she says. Safeguarding traditional livelihoods and the agrarian economy therefore becomes a lot more important today than ever before, she adds.

Not everything is bad news for plastics. Studies have shown that plastic has improved physical or chemical properties compared with alternatives; low cost; mass production capability; and a reduction in the use of resources. Moreover, life-cycle  analysis has shown that using plastic, rather than alternatives, often results  in significant reductions in energy consumption and greenhouse gas emissions in applications ranging from food containers to vehicles and  aircraft.

Pollution to all water bodies is a looming threat facing humankind. Improved waste management operations have to be urgently implemented across the board. Use of plastic materials reached approximately 100 kg per year per capita in North America and Western Europe in 2005 and is expected to increase to 140 kg by 2015. While developing Asian countries use only around 20 kg plastic per year per person which is estimated to increase to 36 kg by 2015.

If plastic is treated as a valuable resource, then its secondary value, after the first intended value, can be tapped through sustainable recycling methods like using of high temperature furnaces with strict emission controls. Successful pollution prevention steps must be taken at all levels – international, national and local. Outreach programs targeting key users must be implemented, new waste management revenue streams must be set up for communities and municipalities. Political commitment, investment and integrated approach at all social levels, to prevent litter from reaching our water bodies will help us move towards a cleaner earth.

Primary source: UNEP Year Book Emerging Issues in our Global Environment 2011