Oceanic pollution : a seventh continent made of plastic

Invisible and innumerable, plastic wastes polluting oceans spread on such a extend that we are talking about a “seventh continent”. 8 million tons of plastic produced each year end up in the oceans. The plastic consumption is only increasing, as well as the waste production. The seventh continent is growing up every day.

A new continent made of plastic wastes

Oceans are saturated with plastic wastes as we’ve already reported in this article. They are directly thrown every day in the seas, or end up there through rivers or sewers. Plastics are definitely one of the main water pollution source. 90% of wastes dumped in the seas are made of plastic.

They are then carried away by marine currents and they massively agglutinate in particular areas : the oceanic gyres in North Pacific and North Atlantic. These are massive whirlpools triggered by the encounter of marine currents. Wastes are thus “trapped” and form huge extents of plastic in the sea, wide enough to be compared to a continent.

This new continent -the seventh- is invisible because the wastes are mainly small and float under the water surface. Such as an iceberg, his immersed part is way bigger than his emerged part.


© Cesar Harada sur Flickr / Courtesy of Algalita Foundation

It’s actually a true pollution “soup” made of 5000 billions, 150 million tons, of plastic pieces. According to estimates, if we brought together all of the plastic debris of the seventh continent, its size would exceed the surface of all the oceans.

It has been identified in the end of the 90s by an American skipper in the north of the Pacific Ocean. He spotted plastic wastes patches drifting on the water. In 2010, a similar discovery is made in the Atlantic North. Today, this pollution doesn’t spare any places on the planet. Plastic wastes are found on small inhabited islands in the Pacific, and even in the Arctic pack ice.

It is well known that plastic take years to deteriorate. In the meantime, they persist as more or less big fragments. With the action of sun, salt and waves, they can decompose in micro and nano-particles.

These small plastic pieces, also called micro-plastics, have a size below one centimeter. The nano-particles are even smaller. Therefore, the plastic pollution of the oceans is hard to see and control.

Plastics and micro-plastics, products of a daily consumption

Mass plastic wastes floating in the oceans result from every products and activities in our day to day life : bottles, bags, packaging, polystyrene, toys, cosmetics, clothing, boat coating, cigarette butts…

Micro-plastics count for 15 to 31% of plastic wastes thrown in the seas each year. We find them in many consumption products such as in the small balls found in some cosmetics and toothpastes.

Clothes are also made of different plastic materials (polyester, synthetic fibers, elastase…). These micro-plastics, too small, escape the filters used in washing machines. Thus, they end up in sewers and then in the nature.

The pollution impact on the environment and marine ecosystems

Talking about a plastic ocean is not an overstatement : at this pace, in 2050, the plastic weight in the oceans will exceed the fish weight !

Pollution also affects ocean floors (fishing nets attached to coral reefs…), while plastic micro-particles trapped in the pack ice accelerate the ice melt.

Some bacterias, seaweeds and shellfish fix themselves to plastic wastes. This way, transported by currents, they migrate through oceans. However, these species can be invasive : they disrupt the marine ecosystem balance in which they settle in.


Wastes are brought on beaches by the waves. On some beaches, there is that many plastic wastes that we don’t even see the sand below anymore. An Hawaiian beach nicknamed “Plastic Beach” is thus sadly known for its pollution.

Plastics destroy marine animals

Plastic pollution is devastating for the marine wildlife. Animals die trapped in nets or ingesting pieces of plastic.

This reality manifests through very sad images such as dead albatrosses, green turtles, sharks and cetaceans, which stomachs are full of plastic trashes.

The victim number is hard to estimate, especially with fishes. Supposedly, plastic kills around 1,5 million animals per year. Among them, we count one million marine birds and 100 000 mammals such as whales and orcas.

Animals confuse plastic wastes with their food, in all levels of the food chain. For example, micro-plastics can be swallowed by plankton, just as well as bigger organisms.

Fishes ingest plastic pieces either directly, or by eating already intoxicated preys. Turtles swallow plastics bags, thinking it is jellyfishes.

Oceanic pollution

© thebiggoodbye sur Flickr

Albatrosses scrutinize the water surface looking for food and confuse plastic wastes with fishes. They bring back trash such as plastic caps in their nests to feed the nestlings.

Animals also risk shocking, swallowing bags and other packagings. Lastly, they can simply starve by consuming plastic instead of food.

30% of Pacific North fishes and 94% of the North Sea birds ingested plastic in their lives.

Plastic ingestion is deadly for animals. Plastic materials contain toxic chemicals such as phthalates. Some plastics integrate and concentrate other dangerous substances present in polluted waters like pesticides. That increases even more their toxicity.

The presence of these toxic plastics in the food chain goes back to the human being, with still unknown consequences on the health.

Stop to the plastic pollution : the solutions considered

There are today two fights to lead : the deletion of non-biodegradable plastic wastes and the oceans cleaning. How can we act ?

  • Collect and manage wastes is the start. It is time to provide a waste collection service to every population which doesn’t has one. It is still nonexistent in developing countries.
  • The plastic recycling is essential to reduce the waste production.
  • Reduce and perhaps eliminate plastics.
  • It goes through sensibilisation : we have to become aware of the impact our wastes have on the environment, change our behaviors, encourage industrials to stop the plastic production and offer better solutions : food packaging and biodegradable or reusable bags in supermarkets…
  • Modify the manufacturing of objects source of plastic pollution, such as tyres, clothes, cosmetics or even washing machines. We could use rubber to make tyres, or put filters capable of stoping microparticules in washing machines.
  • News laws encourage us to continue the efforts : ban of plastic bags on 2016, ban of plastic microbeads in cosmetics in 2018, ban of plastic dishes and cotton buds in 2020.

On the other side, projects about cleaning the oceans are hard to achieve because of technological limits. There is way to much plastic in the oceans and with the size of the nanoparticles, it is a challenge to capture them. New technologies have to be developed to cleanse the oceans.

  • Some sailors offer to navigate in particular sailing boats, equipped with a comb to pick up trash. They will then be stocked on the boat and brought back to the land. It is a small act, which probably won’t clean every sea, but it means a lot.
  • To stay informed and act to save the oceans, you can follow these organizations:


  • To access Expédition 7e continent website, click here.
  • To access Race for Water website, click here.

These two organizations study the plastic pollution and organize awareness and cleaning campaigns.