Marine plastic pollution: A backgrounder

Marine plastic pollution: A backgrounder

  • Plastic is the most prevalent type of marine debris found in oceans.
  • According to UNEP, about 8 million tons of plastic waste enters the world’s oceans each year.
  • Further 60-80% of the litter in oceans is plastic.
  • Currently the focus of studies on marine pollution is microplastic pollution.


Causes of marine plastic pollution

  • Human activities including both land-based and sea-based activities are the major sources of marine pollution in the world.
  • Land-based sources include:
    • Dumping of waste along coastlines
    • Littering on beaches
    • Breaking down of ships
    • Floods and other storm-related events flush this waste into the sea
  • The sea-based sources include:
    • Discarded fishing gear
    • Shipping activities
    • Legal and illegal dumping
  • Poor waste management especially in Asia.
  • Though Europe and America are the largest plastic producers, Asia is the largest dumper of marine waste.
  • According to a study, China was the top dumper of marine waste in the world.
  • India is mismanaging over 80% of its waste compared to 2% in the U.S.
  • Though India generates around 0.34 kg of waste per person per day (ppd), it is the 12 largest marine waste dumper in the world.
  • In contrast, USA though generates 2.58 kg ppd of waste it is the 20th largest dumper.


Impact of marine plastic pollution

  • Economic losses
    • Coastal communities are facing increased expenditures on beach cleaning, public health and waste disposal.
    • The shipping industry is impacted by higher costs associated with fouled propellers, damaged engines, and managing waste in harbours.
    • The fishing industry damaged gear and reduced and contaminated catch.
  • Ecological and biodiversity loss
    • It severely hampers ecosystem functions and services.
    • Fishing gear discared in the sea can entangle and kill marine life.
    • Fishing nets, plastic bags can trap fish and mammals, preventing them from swimming, foraging for food and mating.
    • Plastic causes severe damage to digestive tracts of various species including fish, seabirds etc.
    • Microplastics glued with toxins like pesticides can be ingested by small aquatic life.
    • These toxic microplastics can biomagnify as they move up the food chain accumulating in birds, sea life, humans etc.



  • Plastic debris can come in all shapes and sizes, but those that are less than five millimeters in length are called “microplastics.”



  • Primary source
    • Microbeads: Microplastics of sizes less than 1 mm are added as exfoliants to health and beauty products mostly used in cosmetics, cleaning agents, fiber fragments from washing of clothes, toothpastes etc.
    • Synthetic clothing was the largest contributor of microplastics.
    • The microbeads are mostly made from polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyesters.
  • Secondary source
    • Broken down larger plastic litter and debris.
    • This is a major problem in India’s coast due to mismanagement of land-based plastic waste
    • Recently large debris of plastic was recovered from the gut of dozens of species including mackerel near Mangalore, yellowfish tuna near Kochi and anchovies off the coast of Alappuzha.



  • Microplastics settle in phytoplankton at the base of the marine food chain.
  • These microplastics are ingested by marine fauna, including zooplanktons, mussel, oyster, shrimp, fish, whale etc.
  • These toxic microplastics can biomagnify as they move up the food chain accumulating in birds, sea life, humans etc.


Way Forward

  • To tackle this plastic menace, the UNEP launched CleanSeas campaign in 2017.
  • Under CleanSeas campaign the UNEP is urging governments
    • To enact policies to reduce the use of plastic
    • Targeting industry to minimize plastic packaging and redesign products
    • Calling on consumers to change their throwaway habits.
  • In 2017, the Kerala government began a program called Suchitwa Sagaram to prevent dumping of nets.
  • Accordingly the fishermen can now sell their damaged nets in a buyback programme.
  • Other coastal states should adopt similar programmes in India.
  • While most policies in India focus on ban on large plastics, we should also have a policy on microplastics.
Section : Environment & Ecology