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Debunking the Myths about Plastic Debris in our Ocean

It feels like we have always had plastic. It is so widespread in our lives that it’s hard to imagine a time without it. But in reality, plastic products were only introduced in the 1950s. That was a time when the Earth’s population was 2.5 billion people and the global annual production of plastic was 1.5 million tonnes. Now, nearly 70 years later, plastic production exceeds 300 million tonnes a year[1]and the world population is on its way to 8 billion. If this trend continues, another 33 billion tonnes of plastic will have accumulated around the planet by 2050.[2]

The problem of plastic in the environment has received much attention in the last few years. There is a lot of research going on and new papers are being released almost every day. There have also been hundreds if not thousands of news stories on the subject. But sometimes the issue is blown out of proportion or misconstrued. One consequence of this is that there are a number of myths in wide circulation about the problem of plastic in the ocean, and what it means to the environment and human health. In order to deal effectively with the problem of plastic pollution – or any other environmental challenge – we need facts, not myths or scare stories.

[1] PlasticsEurope, 2016. Plastics—The Facts 2016: An Analysis of European Plastics Production, Demand and Waste Data. PlasticsEurop, Association of Plastics Manufacturers.
[2] UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,


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The goal of this website is to debunk some of these myths.
It presents 10 myths – and 10 often complex realities.

90% of the plastic in the oceans comes from 10 rivers

Plastic gets into the ocean in many ways.  It is dumped directly or is blown in by the wind.  It comes from ships and lost fishing gear. It is also carried by rivers. One estimate of total plastic input to the oceans from all sources is around 8 million tonnes per year, and about 80% is attributed to land based-sources[1]. However, it’s not possible at this stage to accurately verify these figures.

In a recent study of the amount of plastic litter transported by 57 river systems, 10 rivers were estimated to be responsible for 90% of it[2]. In other words, 90% of the plastic coming from rivers is from these 10. It does not mean that 90% of all plastic in the ocean is coming from these 10 rivers. Although there is a great degree of uncertainty with this estimate (ranging from 04. To 4 million tonnes per year), it is a good indicator of the importance of rivers as a source of marine litter. It also helps target regions where better waste management practices are needed.

So, while river-borne plastics are undoubtedly a major source of marine litter, the data is still limited[3] and we should not ignore marine pollution from other sources. One thing we do know is that the presence of plastics in our ocean is linked to human activity – on land and at sea. “All sectors and individuals contribute to this pollution – from poorly controlled waste sites, illegal dumping and mishandled waste on land to ropes, nets, floats and other debris from fishing, merchant shipping, oil rigs, cruise ships and other sources”[4].

River-borne plastics are an important source of marine littler and while research continues into which sources are the most important, we know that plastic in the ocean is a global problem. And it is clear that action by all of us – from individuals to governments – is required to tackle it.

[1] Jambeck, J.R. et al., 2015. Plastic waste inputs from land into the ocean Science, 347(6223), pp. 768-771 (DOI: 10.1126/science.1260352) Available at here
[2] Schmidt, C. et al., 2017. Export of Plastic Debris by Rivers into the Sea. Environ. Sci. Technol., 2017, 51 (21), pp 12246–12253 (Available here).
Stemming the Plastic Tide: 10 Rivers Contribute Most of the Plastic in the Oceans
[3] UNEP, 2016. Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi.
[4]UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,

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Personal care products are the main source of microplastics in the ocean and banning them will solve the problem

Personal care products include microplastics in the form of abrasive microbeads “in face scrubber cosmetics, or plastic raw material granules used in manufacturing.”[1] These particles eventually make their way into wastewater systems and, depending on the efficacy of treatment systems, can end up in the ocean.[2] Much smaller nano-particles are used in sunscreens which can wash off people’s skin at the beach. While there may be a lot of microplastics in a single personal care product – one study estimated from 4,600 to 94,500 microbeads may be released per application of a skin exfoliant[3] – it is not considered a major source and “is relatively small compared with other sources or primary and secondary microplastics in to the environment, in terms of tonnage involved.”[4]

So, while a ban on microbeads in cosmetics is part of the solution to stop microplastics entering the environment, it will not solve the problem on its own. Nevertheless, microbeads serve as a useful illustration for raising awareness about marine litter in the ocean.

[1] Mepex,2014.Sources of microplastic- pollution to the marine environment. Prepared for the Norwegian Environment Agency.
[2] UNEP, 2016. Plastic in Cosmetics.Division of Environmental Policy Implementation. United Nations Environment Programme.
[3] Napper I.E. et al., 2015. Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics. Marine Pollution BulletinVolume 99, Issues 1–2, 15 October 2015, Pages 178-185.
[4] UNEP, 2016. Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi.

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There will be more plastic than fish in the oceans by 2050

It’s nearly impossible to come up with an exact figure to support this claim. A 2016 report estimated that in a “business-as-usual scenario, the ocean is expected to contain 1 tonne of plastic for every 3 tonnes of fish by 2025, and by 2050, more plastics than fish (by weight).”[1] The report was quoted widely in the press but the figures really are just a first attempt to address the issue. Questions have been raised regarding the report’s figures and date of 2050. That’s because there is uncertainty over the methods used to estimate both fish populations[2],[3]and the amount of plastic in the oceans.[4]

So, the “more plastic than fish by 2050” quote is a useful illustration but it is not verifiable. At least not yet.

[1]  World Economic Forum, Ellen MacArthur Foundation and McKinsey & Company, 2016. The New Plastics Economy: Rethinking the future of plastics. Available at here 
[2] Watson, R.A. et al., 2015. Plenty more fish in the sea? Available here 
[3] Homak, L., 2016. Will there be more fish or plastic in the sea in 2050? Available here
[4] Galloway, T. and Lewis, C., 2017. Marine microplastics. Current Biology, 27(11), pp.R445-R446.

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Plastic pollution is currently the biggest threat to the ocean

Over the past couple of decades we have learned that plastic pollution is a significant threat to our oceans. According to a 2015 study,[1] there are 5.25 trillion plastic pieces floating around, equivalent to 720 pieces for every person alive on the planet.  This plastic weighs more than 225,000 tonnes. Another study put the number between 15 and 51 trillion particles, most of which are very small.[2]But debris of any size – from discarded fishing nets to the tiniest particles – can harm marine life when animals become entangled or mistake it for food.[3]

However, while plastic pollution is among the most serious threats, a larger problem may be how it compounds all the other stresses on ocean health. These threats include climate change, acidification, ocean warming, overfishing and habitat destruction.[4]The real problem the ocean faces is the combination of human impacts and our lack of will to address them.

Plastic pollution is just one of the many serious threats to the oceans. And while it might be easy to assume the oceans are dying, they aren’t dead yet. And if we take action now we still have a chance to deal with plastic and other human impacts.

[1] Eriksen, M. et al., 2014. Plastic Pollution in the World’s Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea. Available here
[2] Worm, B. et al., 2017. Annu. Rev. Environ. Resour. 2017. 42:1–26 Available here 
[3] UNEP, 2016. Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi
[4] Halpern, B. S. et al., 2008.A Global Map of Human Impact on Marine Ecosystems. Science 319, 948. DOI: 10.1126/science.1149345

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Microplastics are harmful to humans

There is growing concern about effects marine microplastics may have on people, including toxic chemicals leaching from plastic litter and the fact that “microscopic particles are making their way into the food chain and affecting human health. But are they harmful?”[1]

It appears that the marine food web is full of plastic. It has been found in the stomachs of deep sea fish in the Northwest Atlantic,[2]in fish in the English Channel,[3]in endangered sea turtles,[4],[5]in giant Bluefin tuna off the coast of Lebanon[6]and in the stomach of a whale that died off the coast of Norway in 2017.[7]Concerns include that when ingested, microplastics can affect the feeding behaviours of marine animals and cause weight-loss. Another fear is that when smaller fish are eaten by predators like tuna and swordfish, the plastic moves up the food chain. Chemical pollutants can also bind to microplastics and may increase accumulations of toxins in larger predatory fish – and so particles and toxins can end up on our plates. Such toxins could pass through cell membranes, potentially increasing exposure to harmful chemicals.

However, assessing the risks to human health from marine plastic is complex and there is still much we do not know about its potential to affect human health.[8]In addition, “the uptake of plastic-associated chemicals in humans due to inadvertent ingestion of microplastics in seafood appears likely to be no more significant than other human exposure pathways of these chemicals.”[9]

So, while there is growing concern about the effects microplastics may have on humans, and while the knowledge gap on this subject is narrowing, further work is needed to establish its effects on our health.

[1] UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,
[2] Wieczorek, A.M. et al. , 2018. “Frequency of Microplastics in Mesopelagic Fishes from the Northwest Atlantic.” Frontiers in Marine Science, February 19, 2018,
[3] Lusher, A.L. et ., 2013. Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel. Marine Pollution Bulletin. Volume 67, Issues 1–2, 15 February 2013, Pages 94-99.
[4] Lutz, P.L., 1990. Studies on the ingestion of plastic and latex by sea turtles. In: Shomura, R.S., Yoshida, H.O. (Eds.), Proceedings of the Workshop on the Fate and Impact of Marine Debris. National Oceanic and Atmospheric Administration Technical Memorandum Honolulu, Hawaii (154 pp.). Available here
[5] Caron, al., 2018. Ingestion of microplastic debris by green sea turtles (Chelonia mydas) in the Great Barrier Reef: Validation of a sequential extraction protocol. Marine Pollution Bulletin.
Volume 127, February 2018, Pages 743-751.
[6] Plastic found in belly of tuna highlights waste problem – 
[7] Zoologists say dead whale in Norway full of plastic bags –
[8] UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,
[9] UNEP, 2016. Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi

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There is a large island of trash in the Pacific Ocean and one forming in the Barents Sea

Plastic debris can accumulate in certain areas in the Pacific Ocean and other seas but there are no islands of trash.[1]Not only are there is no islands, there is no layer of trash that can be seen from airplanes. This is because much of the debris found in the ocean is in the form of small particles, not easily seen even from a boat.

In reality these areas, or “patches,” of marine litter consist of higher concentrations of small and tiny fragments of plastic rather than large pieces. But people usually envision seas full of plastic bottles, toys and other big items. In these patches, the number of fragments has been “recorded as over 200,000 particles per square kilometre … that equates to less than one microplastic particle per square metre.”[2]Large plastic pieces do occur but much less frequently. In general, the material is quite dispersed, like a soup of plastic particles. Since these concentrated areas of plastic are formed by dynamic and constantly changing currents, it is extremely difficult to estimate their size.

Concern has also been raised about a potential plastic patch forming in the Barents Sea,[3],[4]however even though the problem may be increasing and affecting fish, marine mammals and seabirds,[5] densities found there are only “slightly higher than those from Antarctica [and] substantially lower than those from temperate waters.”[6]

Regardless of the exact size, mass and location of the “soupy patches of plastic particles,” man-made debris does not belong in the ocean and must be addressed.

[1] Lebreton, L. et al 2018.Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic. Scientific Reports, Vol. 8, Article number: 4666(2018). doi:10.1038/s41598-018-22939-w
[2] UNEP, 2016. Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi
[3] Bergmann, M. et al., 2015. Observations of floating anthropogenic litter in the Barents Sea and Fram Strait, Arctic. Available here
[4] Cózar, A. et al., 2017. The Arctic Ocean as a dead end for floating plastics in the North Atlantic branch of the Thermohaline Circulation. Science Advances 19 Apr 2017: Vol. 3, no. 4, e1600582 DOI: 10.1126/sciadv.1600582
[5] Norwegian Polar Institute, 2018. Plastic in the European Arctic
[6] Bergmann, M. et al., 2015. Observations of floating anthropogenic litter in the Barents Sea and Fram Strait, Arctic. Available here

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Collecting plastic litter floating in the ocean will solve the problem

Collecting floating plastic litter might seem like a good idea but it may divert attention from more cost-effective and efficient measures, such as preventing plastic pollution from entering the ocean in the first place.  And it may cause more harm than good. Plastic in the ocean constantly moves around and is mostly found in low concentrations and throughout the water column.  This makes surface clean-up impractical and ineffective. Due to the scale needed, collecting surface plastics is expected to have very high costs.[1]Researchers are concerned as well with potential high risks and negative effects on marine life and biodiversity associated with surface clean-up schemes.[2]That’s because sea life could become attracted to clean-up gear and exposed to more plastic or entangled in.[3] Among other issues, the surface clean-up equipment itself is expected to become encrusted with biofouling organisms[4]further complicating this potential solution.

Spending time and money collecting plastic floating in the ocean may distract from more practical actions such as coastal clean-ups. [5]

Removing plastic litter from one beach might seem like a mere drop in the ocean when compared to the scale of the problem but clean-ups can be effective when they target ecologically sensitive or economically valuable areas, including places important for fisheries and tourism.

Such efforts can help keep local habitats healthy and keep plastics out of the ocean. They also help raise awareness about the problem of plastic pollution and can spur individual and local action, and help build public support for positive change from producers and governments.[6]

[1] NOAA Office of Response and Restoration. 
[2] Southern Fried Science, 2015. Three facts (and a lot of questions) about The Ocean Cleanup. Blog post. Available here
[3] Southern Fried Science, 2015. Three facts (and a lot of questions) about The Ocean Cleanup. Blog post. Available here
[4] Deep Sea News, 2014. The Ocean Cleanup, Part 2: Technical review of the feasibility study. Available here
[5] OpenChannels, 2014. Interactive panel discussion on utility and feasibility of cleaning up ocean plastics. Video. Available here
[6] NOAA Marine Debris Program, 2016.

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Biodegradable plastics are the answer to marine litter

“Biodegradable plastics” that can break down naturally and disappear from the environment without causing harm may sound like the perfect answer to marine litter, but the reality is not so simple.

A UN Environment report on biodegradable plastics concluded that “the adoption of plastic products labelled as ‘biodegradable’ will not bring about a significant decrease either in the quantity of plastic entering the ocean or the risk of physical and chemical impacts on the marine environment, on the balance of current scientific evidence.”[1]Amongst other factors, the report noted that the “complete biodegradation of plastics occurs in conditions that are rarely, if ever, met in marine environments.”[2]And unfortunately, biodegradable plastics may even contribute to the problem. Although limited, some evidence “suggests that public perceptions about whether an item is biodegradable can influence littering behaviour; i.e. if a bag is marked as biodegradable it is more likely to be discarded inappropriately.”[3]That would certainly defeat the purpose of having biodegradable plastics.

Another reason for not putting all of our eggs in the biodegradable basket is because the issue is really how we use plastic products. The main problem is our love and consumption of single-use and disposable plastics.

Biodegradable plastics and other quick technological fixes may be a distraction from changing our behaviour and other practical and realistic actions. And changing our behaviour and habits is what we really need to do.

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A plastic bottle in the ocean will disappear after 450 years

Recent estimates suggest that it will take 450 years for a plastic bottle to completely break down.[1]However, since plastic bottles didn’t enter into widespread use until the 1960s,[2] it’s hard to know exactly how long it will take for them to disappear.

Breakdown of plastics is caused by solar UV-radiation and is most intensive in environments like beaches and the sea surface. The rate of degradation depends on a number of factors, including composition and temperature.[3]Most plastics “are extremely durable. This means the majority of polymers manufactured today will persist for decades and probably for centuries, if not millennia.”[4]In addition, it is not known when, if ever, full degradation will occur. Larger plastics may fragment into many small microplastics that take longer to break down. And there is no research yet on the degradation of nanoplastics.[5]In fact, there is actually little evidence showing that plastics will ever fully break down in the marine environment.[6]

So, “450 years” is a useful illustration but not a verifiable figure. We don’t know exactly how long it will take. But we do know plastics take extremely long to deteriorate, highlighting the urgent need to prevent more entering the marine environment.

[1] Australian Department of Environment and Conservation. Litter –  How long does it take to break dowmn? Fact Sheet. Available here 
[2] Meikle, J.L., 1995. American plastic: a cultural history. Rutgers University Press.
[3] Andrady, A.L., 2015. Persistence of Plastic Litter in the Oceans. In: Bergmann M., Gutow L., Klages M. (eds) Marine Anthropogenic Litter. Springer, Cham.
[4] UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics. United Nations Environment Programme and GRID-Arendal. Nairobi and Arendal.,
[5] Hansson, L.A. et al., 2015. Nano-plastics in the aquatic environment. Environmental Science: Processes & Impacts, 17(10), pp.1712-1721.
[6] O’Brine, T. and Thompson, R.C., 2010. Degradation of plastic carrier bags in the marine environment. Marine pollution bulletin, 60(12), pp.2279-2283.

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The problem of marine litter is too difficult, nothing I can do will make a difference

Individual actions are key to addressing the global problem of marine litter. Our personal decisions can make a difference.  They help reduce the total amount of plastic entering the environment and ultimately the ocean. Examples of inspirational actions that are making difference around the world include Clean up Kenya, an environmental project to encourage citizens to develop a sense of civic pride in clean neighborhoods. Bye Bye Plastic Bag is a youth-driven environmental campaign to get rid of plastic bags on the island of Bali, Indonesia. The Last Straw is an Australian campaign to end the use of plastic straws. The city of San Francisco is banning plastic bags and water bottles.[1]The Indian state of Maharashtra and the European Union are banning single-use plastics.

With these inspirations in mind, here is how we can all play our part in tackling marine litter:

  • Be an educated consumer– dispose of your waste in responsible manner so that it doesn’t end up in the ocean, reduce your use of unnecessary single-use plastics by choosing reusable items, bring your own waterbottle, check that your cosmetics don’t contain microplastics, carry a shopping bag, use a reusable coffee cup, don’t  take a straw and purchase less food wrapped in unnecessary plastics.
  • Sort and recycle your plastics– recycled plastic means less plastic being produced and entering the environment. It seems obvious, but we could do a better job of it. Don’t we all know someone who needs a little help to recycle properly?
  • Take on and/or support direct action– participate in a local recycling programmes or beach cleanups. Support international campaigns that help remove plastic directly from the environment and prevent it becoming marine litter.

Support your government to address marine litter. Contact your representatives and let them know that this issue is important to you. Urge them to follow the lead of those in Kenya, Bali, San Francisco and many other cities and countries across the world by introducing or supporting policies that make plastic use less desirable.

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Inspiring initiatives

Bye Bye Plastic Bags– a youth-driven environmental campaign to rid plastic bags from the island of Bali, Indonesia.

Clean up Kenya– an environmental project to encourage Kenyan citizens develop a sense of civic pride in clean neighbourhoods.

Indian state of Maharashtra’s single-use plastic ban– includes virtually all types of plastic bags, disposable cutlery, cups and dishes.

The Last Straw– a campaign to end the use of the plastic straws in venues around Australia.

Informative blogs, reports and scientific papers

Boucher, J. and Friot D., 2017. Primary Microplastics in the Oceans: A Global Evaluation of Sources. IUCN, Gland, Switzerland.

Eriksen M et al., 2014.Plastic Pollution in the World’s Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea. PLoS ONE 9(12): e111913.

Hallanger and Gabrielsen, 2018. Plastic in the European Arctic. Norwegian Polar Institute, Tromsø, Norway.

UNEP, 2016. Marine Plastic Debris and Microplastics: Global Lessons and Research to Inspire Action and Guide Policy Change. United Nations Environment Programme, Nairobi, Kenya.

UNEP and GRID-Arendal, 2016. Marine Litter Vital Graphics.United Nations Environment Programme and GRID-Arendal. Nairobi and,

U.S. National Oceanic and Atmospheric Administration’s Marine Debris Blog


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