Covering nearly three-quarters of the Earth, the ocean is an extraordinary resource. We depend on our ocean for the food we eat, the water we drink and the air we breathe. The ocean sustains nearly half of the global primary production and it is home for a multitude of marine organisms. It supports fishing industries and coastal economies, as well as providing recreational opportunities. Land and sea, no matter where we are, are connected. For too long, we have used the ocean as a receptacle for our trash; marine litter has become one of the most pervasive pollution problems facing the world’s oceans.

Marine litter is any persistent, solid material that is manufacturer or processed, and that is directly or indirectly, intentionally or unintentionally discarded, disposed or abandoned in marine and coastal environments. Marine litter includes objects that typically do not naturally occur in the marine environment. The most common materials are: plastic, glass, paper, metal,  rubber  wood and cloth. These materials can enter the environment in two ways: directly through human action or indirectly when blown or washed out to sea via rivers, streams, and storm drains.

Paper is a marine debris which can biodegrade in about 6- 8 weeks
Metal is a marine debris. An aluminium can take up to 200 years to biodegrade. A total of 6,753,260 aluminium cans have been collected on beaches and shoreline worldwide by volunteers during the International Coastal Cleanup (1986 – 2010).
13,585, 425 caps have been collected on beaches and shoreline worldwide by volunteers during the International Coastal Cleanup (1986- 2010)

Once marine litter enters into the ocean, how long it will remain depends upon the material by which they are made of: plastic and synthetic rubber are the most persistent between marine debris.

Over  80 % of marine debris is plastic.

Plastic is the most persistent between marine debris
Over 80 % of marine debris is plastic.
Up to 10 % of plastics produced is estimated to end up in the oceans.
9,549,156 plastic bottles have been collected on beaches and shoreline worldwide by volunteers during the International Coastal Cleanup (1986- 2010)

Look around you. Everywhere we look we will find plastic: in the clothes we wear, in the houses we live in, in our cars, bicycles, planes and trains we travel with. We use plastic for cleaning ourselves, we use plastic for packaging our food, we use plastic for fun in our toys and games, we use plastic in almost every single aspect of our life. Plastic is made of a wide variety of artificial chemical compounds and it can be manufactured in many different shapes, sizes and colours. Plastics are inexpensive, lightweight, strong, durable, corrosion resistant and have with high thermal and electrical insulation properties.

World plastics production has  kept  growing for more than half a century, rising from approximately 1.9 tons in 1950 to 300 million tons in 2013.  In Europe alone, the plastics industry has a turnover in excess of 300 million euros and employs 1.6 million people.

Even though some plastic waste is recycled, up to 10 % of plastics produced is estimated to end up in the oceans.

Researchers estimates that out of a total of 192 countries with coastlines, just 20 countries are responsible for 83% of the plastic debris put into the world’s oceans. These 192 countries produce some 275 million metric tons of plastic waste each year. Of that volume, about 5–13 million metric tons of mismanaged plastic waste is thought to have entered the ocean in 2010. Without improvements to waste management infrastructure, this volume of plastic debris could more than double by 2025.

Plastic enter the oceans from land based sources, when items that are not thrown away correctly, or when they are blown or washed into waterways from landfills and recycling plants. Plastic can also enter the environment from ocean based sources including fishing and cargo vessels, as well as recreational boaters and oil and gas drilling platforms.

Irrespective of how plastics enter the marine environment, they never, truly disappear.

Over time, it will break down to small, microscopic pieces and persist in the environment: plastic never truly goes away, it just becomes smaller and smaller…

Plastic never truly goes away. It just break down into smaller pieces.

Plastics in fact do not biodegrade. Instead, it  breakdown into small pieces due to oxidation or to the physical action of waves, currents, and the grazing activities of fish and birds. Plastic can also break down when exposed to sunlight, a process called photodegradation. Unlike natural material that will break down and be utilised by living organisms, plastic never truly goes away, it just becomes smaller and smaller and smaller….When it breaks into pieces smaller than 5 or 1 mm in diameter, it is known as microplastics.

Microplastics are the most abundant type of plastic in the ocean, and they have been found in every corner of the ocean sampled by scientists to date, from near-shore environments to the open ocean, including remote pacific islands and the Arctic.

Microplastics are  defined as plastics which is anything less than 5 mm in its longer dimension.

Most small microplastics fragments results from the breakdown of larger plastic items but the breakdown of larger pieces of plastic is not the only way in which microplastics end up in the ocean.  The plastic pellets used as a feedstock for producing plastic goods can spill from ships or land-based sources, and “microbeads” used as scrubbing agents in personal care products such as skin cleansers, toothpastes, and shampoos, can escape through water treatment facilities and pass into watersheds with treated water. Eventually, once in the marine environment, microplastic can be transported between all compartments of the water column from surface waters to deep sea sediment. High concentrations accumulate in convergence zones and along exposed coastlines, and in areas with limited water circulation or those surrounded by densely populated urban areas.

Gyres Marta.jpeg
High concentration of plastics accumulate along exposed or densely populated coastlines, as well as in areas with limited water circulation, in convergence zones and in the Gyres. A Gyre is a system of rotating ocean currents. The North Pacific Central Gyre (1 in the figure) contains the most well publicized area of plastic accumulation, known as the “Great Pacific Garbage Patch”. Microplastics concentration has here increased by two order of magnitude in the last 40 years.

Recent scientific researches estimate that 5.25 trillion of plastic pieces, the majority microplastics, are floating in the world’s oceans and meet with phyto and zooplankton, crustaceans, molluscs, fish, turtles,  seabirds and marine mammals every single day.

Scientists have found that plastic affects at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. It is quite scary to think that this numbers may be highly underestimated as most victims are likely to go undiscovered by scientists, as many sink or are eaten by predators.

Plastics harms wildlife in both a direct and indirect ways. The direct effects of plastic include plastic ingestion and entanglement.

Entanglement in plastic debris, especially in discarded fishing gear, is a very serious threat to marine animals. It can cause wounds that can lead to infections or loss of limbs; can impair an animal’s ability to swim, which may lead to drowning, or make it difficult for the animal to move, find food, and escape from predators, or can cause strangulation, choking, or suffocation. More than 100,000 marine mammals die every year from entanglement or ingestion of marine debris.

More than 100,000 marine mammals die every year from entanglement. Picture of a grey seal.
9608572423_d952831b71_o (2).jpg
Between all marine mammals, seals and sea lion are the most affected by plastic entanglement  because of their natural curiosity and tendency to investigate unusual objects in the environment. Photo of harbour seals.

Fishing nets, fishing line, ropes, plastic sheeting and packing straps can be a major problems for animals that interact with fisheries, such as dolphins. Fish and crustaceans are frequently entangled in lost or discarded fishing items, a phenomenon  known as ghost fishing. Thousands of seabirds are thought to die from entanglement or ingestion each year. When birds prey upon entangled fish, they can become entangled themselves.

Wildlife eat plastics. Some have the ability to remove it from their mouths, but ingestion occurs when an animal swallows the plastic item. Ingestion can be accidental, but animals may ingest debris because it actually looks like food.

Once ingested, plastic can cause the blockage of the secretion of gastric enzyme, can diminish the  feeding stimulus,  can lower the levels of steroid hormone or even delay ovulation and cause reproductive failure.

Many types of birds have been found to feed on plastic pieces, most likely because they mistake them for food. Plastic eaten by adult birds can be regurgitated as food for hatchlings, potentially generating a population problem, especially when the offspring are never fed real food. Also loggerhead sea turtles have been found to feed on plastic and at least 26 species of cetaceans have been documented to ingest plastic debris. A number of benthic invertebrates including lugworms, amphipods and blue mussels can feed directly on microplastics. Microplastics are ingested by commercially important invertebrate species, including crustaceans and bivalves. Also microplastic ingestion by wild caught fish species is not an uncommon observation. For example, commercially caught fish and mesopelagic fish from the English Channel and the North Pacific had microplastics in their digestive tracts.

Wildlife eats plastics. Stomach content of a beached Northern Fulmar, dissected by Heidi Acampora as part of The Republic of Ireland Beached Seabirds Survey, a project that uses beached seabirds to describe the ingestion of marine litter in Ireland. Foam and plastics fragments are the main component of the sample. Picture taken by Nicolò Ongaro

The indirect effects of plastic may include chemical leaking. Plastic debris contains chemicals that are added to the polymers in the production phase in order to give to the material the required characteristics of colour, texture and flexibility. But they also absorb environmental contaminants from the water. Plastic acts in fact as a sort of sponge, accumulating pollutants such as PCBs from seawater. These chemicals could have negative effects on animals that ingest contaminated plastics.

Another indirect effect of plastic pollution is the introduction of alien species. Plastics floating at sea may be colonised by various encrusting organisms such as bacteria, diatoms, algae, barnacles, hydroids and tunicates. Drift plastics can introduce species into an environment where they were previously absent. The arrival of unwanted and aggressive alien species could be detrimental to littoral and shoreline ecosystems.

Land and sea, no matter where we are, are connected.

Any trash that is disposed of improperly can potentially enter the ocean or other waterways, and anyone who disposes of trash improperly can be a source of marine debris! Yes, even you!

Marine debris is one of the greatest threats our ocean faces, but luckily it is an issue with which we can all play a part in the solution.

We all should be aware that plastics and plastic chemicals are ubiquitous, and we truly can’t eliminate all risks associated with plastics. But we can reduce them, and we can chose to support businesses and institutions that are attempting to do the same.

Plastic pollution can be reduced by using less plastics products and switching to alternatives.

Among the existing solutions recycling is one of the most convenient and easiest ways. As consumers, the recycling only requires one easy step of putting plastic wastes in right bins for disposal.

To be effective our actions should embrace the so called five R’s: ‘reduce, reuse, recycle, recover and redesign’.

There are some very simple actions which everyone of us can take to reduce our plastic footprint:

  1. Try to avoid using or buying items that used an unnecessary amount of plastic.
  2. Avoid plastic bottled water (carry around with you your own flask, fill it when you are thirsty)
  3. At home, drink tap water. If you do not like the taste, add a few slice of fruit or filter the water thanks to in-expensive filter jugs. Tap water is better than bottled water because it isn’t stored in plastic and has much higher regulation standards
  4. Don’t buy beverages bottles made of plastic
  5. Bring your own cloth bags when shopping. Remember that between 500 billion and a trillion plastic bags are consumed worldwide each year. Less than 1% of bags are recycled. Plastic bags are used for an average of 12 minutes, but a single plastic bag has a life expectancy of up to 1,000 years!!!
  6. Cosmetic choice: avoid all scrubbing products containing plastic. Did you know that the best scrub ever is done with inexpensive and completely biodegradable products, such as honey and brown sugar? Give it a try!
  7. Carry your own reusable steel or ceramic beverage container.
  8. Store all your food in glass containers instead of plastic containers.
  9. Don’t buy convenience foods packages in plastic, avoid fruit wrapped in plastic and prefer fresh eggs in reusable paper containers.
  10. Prefer natural fabrics
  11. Say no to plastic straws. You can buy stainless steel and glass straws to carry with you
  12. Do not release balloons: you may have fun, but the animal that is ultimately going to encounter it won’t be of the same opinion!
  13. Recycle your six-pack holders wherever is possible. If you can’t recycle, you can always cut or tear the rings to prevent marine animals entanglement.
  14. Smokers: Use matches instead of plastic encased lighters and use portable ashtray to prevent the loss of plastic filters (cigarette butts) into the environment



Acampora, H., Lyashevska, O., Van Franeker, J. A., & O’Connor, I. (2016). The use of beached bird surveys for marine plastic litter monitoring in Ireland. Marine Environmental Research 120: 122-129.

Bergmann, M., Gutow, L., & Klages, M. (Eds.). (2015). Marine Anthropogenic Litter. Springer International Publishing.

Derraik, J. G. (2002). The pollution of the marine environment by plastic debris: a review. Marine pollution bulletin 44(9): 842-852.

Eriksen, M., Lebreton, L. C., Carson, H. S., Thiel, M., Moore, C. J., Borerro, J. C., … & Reisser, J. (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).

Gregory, M. R. (2009). Environmental implications of plastic debris in marine settings—entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions. Philosophical Transactions of the Royal Society of London B: Biological Sciences 364(1526): 2013-2025.

Lusher, A. L., McHugh, M., & Thompson, R. C. (2013). Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel. Marine pollution bulletin 67(1): 94-99.

Lusher, A. L., Tirelli, V., O’Connor, I., & Officer, R. (2015). Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples. Scientific reports 5.

Ryan, P. G., Moore, C. J., van Franeker, J. A., & Moloney, C. L. (2009). Monitoring the abundance of plastic debris in the marine environment.Philosophical Transactions of the Royal Society of London B: Biological Sciences 364(1526): 1999-2012.

Thompson, R. C., Olsen, Y., Mitchell, R. P., Davis, A., Rowland, S. J., John, A. W., … & Russell, A. E. (2004). Lost at sea: where is all the plastic? Science 304(5672): 838-838.

Thompson, R. C., Moore, C. J., Vom Saal, F. S., & Swan, S. H. (2009a). Plastics, the environment and human health: current consensus and future trends. Philosophical Transactions of the Royal Society B: Biological Sciences 364(1526): 2153-2166.

Thompson, R. C., Swan, S. H., Moore, C. J., & Vom Saal, F. S. (2009b). Our plastic age. Philosophical Transactions of the Royal Society B: Biological Sciences 364(1526): 1973-1976.

Wilcox, C., Van Sebille, E., & Hardesty, B. D. (2015). Threat of plastic pollution to seabirds is global, pervasive, and increasing. Proceedings of the National Academy of Sciences 112(38): 11899-11904.

Wright, S. L., Thompson, R. C., & Galloway, T. S. (2013). The physical impacts of microplastics on marine organisms: a review. Environmental Pollution 178: 483-492.


  1. Hey there! I just posted about plastic too and came across this! Love how detailed this is. I concentrated on what we could do from home. Interesting read! Looking forward to more!

    Liked by 1 person

    1. Hey Nusrath! Thanks a lot for your feedback! We have created other materials on plastic pollution, especially videos; you can find them on our youtube channel, in the playlist Plastic Pollution! Hope you will find them interesting, plastic pollution is surely an issue for which every effort to raise people awareness is needed and welcome


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