Plastic in the ocean

Phytoplankton consumes carbon dioxide during photosynthesis. These small microorganisms are food source of many Zooplankton thus critical for survival of life in Sea. Image from :


  • Plastics comprise 50–80% of the litter in the oceans
  • An estimate from United Nations Environment Programme (UNEP) says that fishing gear makes up 10% of all marine litter which is around 640,000 tonnes.
  • Global production of plastics is above 300 million tonnes per year. A large part of it ultimately ends up in the ocean.
  • The nets used for fishing and dumped in the ocean after they are no longer fit to be used, tyres, buoys, buckets, bottles and bags are major source of plastic found in the oceans worldwide.
  • Fishing net traps and kills many animal species ranging from turtles to seals to birds.
  • It is observed that approcimately 90% of the Seabirds called fulmars that are washed ashore dead in the North Sea had plastic in their guts.

Oxygen is the key for life on Earth, all living beings depends on it for their survival. All of us know that oxygen comes from plants but the interesting fact is that, these oxygen machines not only grow on land but also in water.

Here is the fact, majority of oxygen that we take in is produced by the tiny plants found in sea water known as Phytoplanktons.

Phytoplanktons are small microscopic organisms found in water and produce oxygen using sunlight and nutrient from water. Not only Phytoplanktons produce oxygen and help in carbon fixation but also serve as food for various organisms in marine ecosystem.

The oxygen generated by these small plants are difficult to quanitify but some scientists believe that more than half of the total world’s oxygen is generated by Phytoplanktons.

Plastic in the ocean is a major threat to Phytoplanktons and to the entire marine ecosystem

The research suggests that plastic pollution in the marine is harmful as it is proved to be toxic to phytoplanktons and the higher marine animals ranging from turtles to seals to birds that are part of the marine food chain.

Ocean life is threatened by increasing pollution. And one pollutant that is common in all marine areas is plastic waste. A recent article published in nature detailed out how plastic reaches to world oceans and poisoning life in the sea.

The plastic that reaches Oceans by different channels accumulates in the digestive system of animals, interfere with their reproductive system and harm them.

Like this Baby Albatrosses (a seabird) thousands of birds die annually around the World have found to have accumulated plastic wastes in their guts. Image Source:

“There are three types of plastic pollutants identified by researchers in sea i.e. Macro (size >200mm), Meso (size 4.76-200mm), Larger Micro Plastics (size 1.01-4.75mm) and Microplastics (.33-1mm). The plastic wastes of different sizes are coming from different sources.

How does plastic get into the ocean

Larger plastic wastes in our oceans are coming from fishing gears left in the seas such as nets, buckets lines and the waste material that enters into the sea through beaches. Microplastics are smaller peices of plastic that break down due to sunlight or waves”. Few identified sources are waste water from washing machine , wear and tear of tyres, other plastic products and micro beads added in cosmetic products that drains into water bodies.

Effective plastic waste management with long term impact assessment is required

Plastic is a non-biodegradable component and its disposal is very difficult. As a result it keeps accumulating in the system. Over the years the demand for dump yards to dispose them off have increased.

A technological solution being popularized to manage plastic waste involves using plastic for constructing roads. It is appreciated by both scientific as well as administrative authorities in India.

This technique is now being promoted by various Governments, especially in the rural areas. With regard to the adoption of this technology, certain queries have to be addressed:

  • Whether a risk assessment of this technology has been carried out or not?
  • Are these roads made up of plastic material not going to degrade with time?
  • If these roads wear and tear in future, where the released degraded plastic compounds will go? Is there any chance of its eventually mixing with and polluting water bodies?

Without proper scientific long term assessments, the use of this technology for constructing roads is only an effort to  shift the location of the plastic from dump yards to roads.

End Note

Our water bodies are becoming toxic because of our negligence. News of dead fish washing away to the beaches, people getting sick by eating contaminated seafood are now frequent. These are warning signs that are needed to be taken seriously if we do not want our oxygen producing marine life to die out. It is unlike our land ecosystem where it is feasible to compensate the loss by planting trees. In marine ecosystem we  need to protect what exists.

Few concerned citizens are doing their bit by taking part in beach clean ups across the world. But what actually required is strong monitoring system for the vast coastline.

The article originally appeared in a online portal ‘ Facts n Me’ focused on Environment & Climate