Oceans of Plastic

We had the story this week(1) that our planet’s oceans are now so polluted with waste plastics, that an estimated 90% of all sea birds have ingested plastic.

If the current ‘trend’ continues, the data extrapolations(2) by Imperial College London (ICL) suggest that by 2050, 99% of sea birds will have plastic in their guts. The data gathered and analysed by ICL commences in 1960, where research suggests only 5% sea birds had ingested plastic.

What damage does the ocean borne plastic do?

In terms of wildlife and sea birds affected by plastic pollution, it is estimated(4) that at least one million sea birds die each year as a result.

Furthermore, because of plastic pollution, one-hundred thousand marine mammals also die each year. The survival of at least 100+ species could be jeopardized by plastic debris, with plastic pollution also serving as an unwanted carrier of invasive species, threatening native ecosystems.

Plastic debris can absorb and concentrate toxic chemical within its structure, including absorbing PCBs and DDTs(5) (both are suspected carcinogens).

Concentrations of toxins in plastics can be more than a millions times higher than normal, background levels(4).


PCBs and DDT are chemicals that were banned more than 30 years ago, but our air, water, land, and bodies are so contaminated, that decades of clean-up efforts have yet to eliminate their threats to our health(5).

The effects of PCBs on human health manifests in deterioration in child development (physical and mental), tumours, toxic to the immune system, reproductive organs, and thyroid.

Human exposure to DDTs is harmful to the nervous system, causing dizziness, tremors, irritability and convulsions. Workers with longer term exposure have lasting neurological and cognitive problems. Pregnant women exposed to DDT are more likely to have premature or small-for-gestational-age babies. DDT is considered a hormone disrupting chemical due to its estrogen-like properties. DDT causes cancer in laboratory animal experimentation.

Ultimately, these toxins end up in the human food chain – In fish, the persistent organic pollutants bio-accumulate inside them, upon entry in the food chain this results in even higher concentration levels of pollutants.

One of the main reasons cited for so many sea birds ingesting plastics is the birds mistaking glimmering objects as potential food, or indeed ingesting contaminants along with their food intake. The contaminants in the bird’s intake leads to gut impaction, weight loss and in extreme cases the bird’s premature death.

Where does this ocean borne plastic come from?

In a February 2015 study(3) it was discovered that sea birds had ingested plastic bags, bottle caps, and plastic fibres from synthetic clothes, this plastic debris having been washed out to sea from urban rivers, sewers and waste deposits.

During the study, one sea bird was found to have ingested some 200 pieces of plastic.

It was concluded(3) that annually, some 8.8 million tonnes of plastic debris is being ‘fed’ into our planet’s oceans. If the current trend continues, by 2025 the total accumulated plastic debris in the planet’s oceans will reach around 170 million tonnes [based on population trends and continued waste management ‘disposal’ problems]

This study(3) superseded similar past studies, by using World Bank statistics on 192 countries’ waste streams to track and estimate plastic pollution from the source, looking at the debris entering the ocean from land, sea and other pathways:

The Study’s Author, Jambeck said – “the mismanaged waste and solid waste dispersed was the biggest contributor of all of them.”

Fabrice Monteiro_Ocean

Image: Fabrice Monteiro

Which countries are the offenders?

The study(3) (which included 192 countries) concluded that the biggest polluters are mostly developing Asian countries – with 5 countries responsible for more than 50% of the plastic waste in our oceans; namely China, Indonesia, Philippines, Vietnam and Sri Lanka. The only industrialized western country on the list of top 20 plastic polluters is the United States at No. 20. [Update] However, more recent work has identified ‘trade’ in plastic waste to Asian countries as a major factor and how past reports have been manipulated by lobbies with vested interests:

“……… data has been published showing that the US ranks third among countries contributing to coastal plastic pollution and challenges the widely held belief that the US is adequately managing its pollution, underlining its waste footprint to developing nations.”

To put the ranking into perspective China is responsible for 2.4 million tonne of plastic in the planet’s oceans (nearly 28 per cent of the world total) whereas the United States contributes 77,000 tons (less than 1 per cent of the world total).

The study(3) concluded mismanagement was not the cause in the case of the European countries listed, or the United States, but cited the populations’ (avoidable) littering as the cause.

Table 1 – Waste estimates for 2010 for the top 20 countries ranked by mass of mismanaged plastic waste (in units of millions of metric tons per year) [Update] Alos see “The United States’ contribution of plastic waste to land and ocean,” 2020

Source: Reference(3)


Rank Country Econ. classif. Coastal pop. [millions] Waste gen. rate [kg/ppd] % plastic waste % mismanaged waste Mismanaged plastic waste [MMT/year] % of total mismanaged plastic waste Plastic marine debris [MMT/year]
1 China UMI 262.9 1.10 11 76 8.82 27.7 1.32–3.53
2 Indonesia LMI 187.2 0.52 11 83 3.22 10.1 0.48–1.29
3 Philippines LMI 83.4 0.5 15 83 1.88 5.9 0.28–0.75
4 Vietnam LMI 55.9 0.79 13 88 1.83 5.8 0.28–0.73
5 Sri Lanka LMI 14.6 5.1 7 84 1.59 5.0 0.24–0.64
6 Thailand UMI 26.0 1.2 12 75 1.03 3.2 0.15–0.41
7 Egypt LMI 21.8 1.37 13 69 0.97 3.0 0.15–0.39
8 Malaysia UMI 22.9 1.52 13 57 0.94 2.9 0.14–0.37
9 Nigeria LMI 27.5 0.79 13 83 0.85 2.7 0.13–0.34
10 Bangladesh LI 70.9 0.43 8 89 0.79 2.5 0.12–0.31
11 South Africa UMI 12.9 2.0 12 56 0.63 2.0 0.09–0.25
12 India LMI 187.5 0.34 3 87 0.60 1.9 0.09–0.24
13 Algeria UMI 16.6 1.2 12 60 0.52 1.6 0.08–0.21
14 Turkey UMI 34.0 1.77 12 18 0.49 1.5 0.07–0.19
15 Pakistan LMI 14.6 0.79 13 88 0.48 1.5 0.07–0.19
16 Brazil UMI 74.7 1.03 16 11 0.47 1.5 0.07–0.19
17 Burma LI 19.0 0.44 17 89 0.46 1.4 0.07–0.18
18* Morocco LMI 17.3 1.46 5 68 0.31 1.0 0.05–0.12
19 North Korea LI 17.3 0.6 9 90 0.30 1.0 0.05–0.12
20 United States HIC 112.9 2.58 13 2 0.28 0.9 0.04–0.11

*If considered collectively, coastal European Union countries (23 total) would rank eighteenth on the list

 Figure 1 Source: Reference(3)

Ocean Pollution by Country_V2

Other issues with discarded and mismanaged plastic waste

Micro-plastics are used as an exfoliator (to replace natural exfoliators) in cosmetics such as hand cleansers, soaps, toothpaste, shaving foam, bubble bath, sunscreen and shampoo.

Micro-plastics, are defined as plastics in the form of microbeads (each a fraction of a millimetre in diameter), where it has been suggested that almost 100,000 ‘microbeads’ can be released in every single application of certain products, such as facial scrubs.

These plastic microbeads are causing unnecessary contamination(6) of the oceans. With micro-plastics now entering the marine food chain, they can be ingested by fish and shellfish and there is evidence from laboratory studies of adverse effects on marine organisms.

How can the planet’s oceans be cleaned up?

Well, first the burden of plastic waste entering the planet’s oceans needs to be brought under control with some (seemingly) simple steps:

  1. The worse offending countries (see above) need to implement proper waste management controls and systems;
  2. Banning of plastic as a packaging material, single-use plastic containers, bags;
  3. Imposing a charge for use of plastic bags and reducing demand and casual disposal (littering);
  4. Clamping down on general litter and litter offending.

‘Cleaning’ the planet’s vast oceans sounds like a daunting task at first sight. It has been estimated(4) that using vessels and nets to collect the plastic from one ocean “garbage patch” would take about 79,000 years and tens of billions of dollars, not to mention the negative environmental impact of all the collecting vessels plying the ocean.

Globally, it is estimated(3) plastic pollution causes costs of at least US $13 billion each year to industries that include fishing, shipping, tourism and the cleaning of coastlines (UNEP 2014). The US West Coast spends approximately US $500 million each year to clean up their beaches. The costs of removing debris from beaches is on average US $1,500, and up to US $25,000 per ton (APEC 2009).

Boyan Slat – Ocean Clean Up

Then came the remarkable story, a ray of hope in the form of a young, Dutch schoolboy, Boyan Slat, a keen ocean diver from Delft, The Netherlands. He was inspired to act following a school assignment, plus the revolt of seeing people casually throwing rubbish into the water whilst he was exploring the underwater ecosystems of the Azores islands off the coast of Portugal.

Two years later, that school assignment morphed into Ocean Clean Up(4) and became the most successful not-for-profit crowd-funding campaign in the history of the internet, when in June 2014 Ocean Clean Up raised more than $2m USD (with the support of over 38,000 funders from 160 countries, in 100 days)(4).

The Ocean Clean Up system works off the world’s ‘gyres’ (tidal flows that direct the oceans’ rubbish to five central points).

Figure 2 – The Plastic Pollution Problem

Source: Reference(4)

Plastic Polution Problem_The Ocean Clean Up

Researcher discovered the Pacific’s “Garbage Dump” contains some 7.25 million tonnes of plastic floating in the gyres, equivalent to 1000 Eiffel Towers, which would take at least 79,000 years to clean up at the current rate.

Compared with the burden of vessels and nets to collect the “garbage,” the Ocean Clean Up’s research into the feasibility of its own concept indicates that using a single 100 km clean-up array, deployed for 10 years, will passively remove 42% of the Great Pacific Garbage Patch, with this “conservative” estimate equating to the removal of 70 million tonnes at a clean-up cost of a mere € 4.53 per kilo.

Figure 3 – Rendering of Ocean Clean Up’s Concept

Source: Reference(4)

Ocean Clean Up Picture

Ocean Clean Up’s – First Deployment in 2016

In May 2015, Slat announced that the world’s first ocean self-cleaning system was about to be deployed in the sea separating Japan and Korea(4).

The trial between the Japanese island of Tsushima and South Korea is one step towards cleaning the ocean in a fraction of that time. In all of five years, Slat believes.

A platform in the shape of a manta ray is being built. It will have two huge floating arms spanning two kilometres from its central point that will allow sea life to pass under it while the buoyant plastic rubbish is captured within it.

Slat believes Ocean Clean Up’s project could have commercial appeal:

If you sold the plastics collected by the gyres you would make over $US500 million, more than it would cost to execute. It would be profitable.”

Ocean Clean Up’s Mega Expedition – Pacific Deployment in 2020

On the 23 August 2015, Ocean Clean Up announced successfully concluding the Mega Expedition with the arrival of a first group of vessels including the fleet’s 171ft mothership in the port of San Francisco. Using a series of measurement techniques, including trawls and aerial surveys, the fleet of close to 30 vessels sampled the concentration of plastic during its month-long voyage through the Great Pacific Garbage Patch. This is in preparation for the large-scale clean-up of the area, set to begin in 2020.

The Mega Expedition’s primary goal is to accurately determine how much plastic is floating in the Great Pacific Garbage Patch, by executing the largest ocean research expedition in history. This was also the first time large pieces of plastic, such as ghost nets and Japanese tsunami debris, have been quantified.


Boyan Slat of Ocean Clean Up(4), is still completing his studies in aerospace engineering at the Delft University of Technology, whilst still working with the Ocean Clean Up project.

In 2014, Slat’s work on the Ocean Clean Up programme earned him the United Nations Champions of the Earth award, not a bad achievement for a 19-year-old – “It’s rather strange to be on a list with all these senior and successful people who have already accomplished a lot” he modestly suggested.

The level of plastic pollution in the planet’s oceans is truly shocking. The resulting toxins entering the food chain are almost unimaginably horrific. The problem is only likely to worsen without urgent remedial action.

Can the situation improve? Well yes, but only if countries such as China, Indonesia, Philippines, Vietnam and Sri Lanka take the conscious decision to improve their waste management systems to at least make the pollution less of an increasing burden. [Update] However, more recent work has identified ‘trade’ in plastic waste to Asian countries as a major factor.

Then we have the privilege of one remarkable young man stepping into the fray – Boyan Slat, who has taken on a truly Herculean task with the Ocean Clean Up team on the planet’s behalf.

Ocean Clean Up’s planned projects and concept are a work of simple genius and gives me hope (just a little bit) that the plight of our planet and the species upon it, can be improved. But this improvement will only be realised if there is more effort from the many, not just the remarkable few.

References and Notes

(1) “Plastic pollution wreaking havoc; 90% of all seas birds have ingested plastic” –Techie News, Ravi Manalia, 1 September 2015

(2) CSIRO and Imperial Collage, London

(3) University of Georgia College of Engineering, Jenna Jambeck, Assistant Professor of Environmental Engineering, “Plastic waste inputs from land into the ocean” – Science 13 February 2015: Vol. 347 no. 6223 pp. 768-771, DOI: 10.1126/science.1260352, Jenna R. Jambeck, Roland Geyer, Chris Wilcox, Theodore R. Siegler, Miriam Perryman, Anthony Andrady, Ramani Narayan, Kara Lavender Law.

(4) Ocean Clean Up – http://www.theoceancleanup.com/

The Ocean Clean Up Technology

  1. Why move through the oceans, if the oceans can move through you? Instead of going after the plastic using boats and nets, The Ocean Cleanup will use long floating barriers, using the natural movement of the ocean currents to passively concentrate the plastic itself.
  2. Virtually all of the current flows underneath these booms, taking away all (neutrally buoyant) sea life, preventing by-catch, while the lighter-than-water plastic collects in front of the floating barrier.
  3. The scalable array of floating barriers, attached to the seabed, is designed for large-magnitude deployment, covering millions of square kilometers without moving a centimeter.

(5) http://www.watoxics.org/chemicals-of-concern/pcbs-and-ddt

PCBs – polychlorinated biphenyls

PCBs are synthetic (human-made) chemicals first produced in the late 1920s. They were used as cooling fluids in electrical equipment and machinery because of their durability and resistance to fire.

Monsanto stopped producing them in 1977.

The US Environmental Protection Agency (EPA) mandated phase out of most uses shortly thereafter.

PCBs have a similar chemical structure to PBDEs, which are currently used as flame retardants in electronics, furniture, and other consumer goods.

PCBs can have profound effects on intellectual development. Children with greater exposure to PCBs have lower birth weights, slowed growth, and poorer performance on tests of brain development.

PCBs cause tumours in laboratory animals. EPA lists PCBs as probable human carcinogens. Studies suggest that PCBs are also toxic to the immune system, reproductive organs, and thyroid.

DDT – dichloro-diphenyl-trichloroethane

DDT was developed as an insecticide in the 1940s, and was widely used during World War II to combat insect-borne diseases.

DDT’s effectiveness, persistence, and low cost made it popular for agricultural and commercial uses. More than a billion pounds were used in the U.S. over a 30-year period.

The EPA banned nearly all domestic uses of DDT in 1972, after the publication of Silent Spring and broad public outcry about DDT’s impacts on wildlife and people.

Today, use of DDT is limited to malaria control programs in some developing countries. Exposure to DDT is harmful to the nervous system. People exposed to high levels exhibit dizziness, tremor, irritability, and convulsions. Workers with longer term exposure have lasting neurological and cognitive problems.

Pregnant women exposed to DDT are more likely to have premature or small-for-gestational-age babies. DDT is considered a hormone disrupting chemical due to its estrogen-like properties.

DDT causes cancer in laboratory animals. EPA lists DDT as a probable human carcinogen.

(6) Professor Richard Thompson at Plymouth University, has been studying the effects of litter in the marine environment for over 20 years.

Further Reading

NGO retracts ‘waste colonialism’ report blaming Asian countries for plastic pollution,” The Guardian, 15 September 2022

Pacific Ocean garbage patch is immense plastic habitat,” BBC News, 4 December 2021

5 thoughts on “Oceans of Plastic

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