Ocean Pollution (Marine Pollution) – Geography UPSC NOTES

• Oceans are the largest water bodies on the planet Earth. Over the last few decades, excessive human activities have severely affected marine life in the Earth’s oceans. Ocean pollution, also known as marine pollution, is the spreading of harmful substances such as oil, plastic, industrial and agricultural waste, and chemical particles into the ocean.
• Since oceans provide the home to a wide variety of marine animals and plants, it is the responsibility of every citizen to play his or her part in making these oceans clean so that marine species can thrive for a longer period of time.

​​​​​Laws and Policies

•    In 1948, Harry Truman signed a law formerly known as the Federal Water Pollution Control Act that allowed the federal government to control marine pollution in the United States of America.
  • In 1972, the Marine Protection, Research, and Sanctuaries Act of 1972 was passed by the Council on Environmental Quality which controls ocean dumping.
  • In 1973 and 1978, MARPOL was a treaty written to control vessel pollution, especially regarding oil. In 1983, the International Convention for the Prevention of Pollution from Ships enforced the MARPOL treaty internationally.
  • The 1982 United Nations Convention on the Law of the Sea (UNCLOS) was established to protect the marine environment by governing states to control their pollution of the ocean. It puts restrictions on the amount of toxins and pollutants that come from all ships internationally.

Causes of Ocean Pollution

• Plastic: 4-12 million metric tons of plastic goes into the sea. India generates 62 million metric tons of waste every year of which 10-12% is plastic waste and this also constitutes single-use plastics.
• Sewage: Pollution can enter the ocean directly. Sewage or polluting substances flow through sewage, rivers, or drainages directly into the ocean. In India, 80% of municipal sewage is collected of which only 20% is treated and the rest are directly discharged into oceans.
• Toxic Chemicals from Industries: Industrial and agricultural waste is another most common form of waste that is directly discharged into the oceans, resulting in ocean pollution. The dumping of toxic liquids in the ocean directly affects marine life.
• Land Runoff: Land runoff is another source of pollution in the ocean. This occurs when water infiltrates the soil to its maximum extent and the excess water from rain, flooding or melting flows over the land and into the ocean. Often, this water picks up man-made, harmful contaminants that pollute the ocean, including fertilizers, petroleum, pesticides, and other forms of soil contaminants. 80% of the land discharge goes into the sea in the form of plastic waste.
• Large-Scale Oil Spills: Ship pollution is a huge source of ocean pollution, the most devastating effect of which is oil spills. Crude oil lasts for years in the sea and is extremely toxic to marine life, often suffocating marine animals to death once it entraps them. Crude oil is also extremely difficult to clean up, unfortunately meaning that when it is split; it is usually there to stay.
• Ocean Mining: Ocean mining in the deep sea is yet another source of ocean pollution. Ocean mining sites drilling for silver, gold, copper, cobalt, and zinc create sulfide deposits up to three and a half thousand meters down into the ocean.
• Littering: Pollution from the atmosphere is, believe it or not, a huge source of ocean pollution. This occurs when objects that are far inland are blown by the wind over long distances and end up in the ocean. These objects can be anything from natural things like dust and sand to man-made objects such as debris and trash. Most debris, especially plastic debris, cannot decompose and remains suspended in the ocean’s current for years.

Devastating Effects of Ocean Pollution

• Effect of Toxic Wastes on Marine Animals: The oil spill is dangerous to marine life in several ways. The oil spilled in the ocean could get onto the gills and feathers of marine animals, which makes it difficult for them to move or fly properly or feed their children. The long-term effects on marine life can include cancer, failure in the reproductive system, behavioral changes, and even death.
• Disruption to the Cycle of Coral Reefs:
  • Oil spill floats on the surface of the water preventing sunlight from reaching to marine plants and affecting the process of photosynthesis. Skin irritation, eye irritation, and lung and liver problems can impact marine life over a long period of time.
    • Depletes Oxygen Content in Water
    • Failure in the Reproductive System of Sea Animals
    • Effect on Food Chain
  • Chemicals used in industries and agriculture get washed into the rivers and from there are carried into the oceans. These chemicals do not get dissolve and sink at the bottom of the ocean. Small animals ingest these chemicals and are later eaten by large animals, which then affect the whole food chain.
• Eutrophication: When a water body becomes overly enriched with minerals and nutrients which induce excessive growth of algae or algal bloom.
  • This process also results in oxygen depletion of the water body.
• Affects Human Health: Animals from the impacted food chain are then eaten by humans which affects their health as toxins from these contaminated animals get deposited in the tissues of people and can lead to cancer, birth defects or long-term health problems.

Solutions for Ocean Pollution

• A stricter government regulation on industry and manufacturing is one large-scale solution.
• Implement renewable energy sources, such as wind or solar power, to limit offshore drilling.
• Limit agricultural pesticides and encourage organic farming and eco-friendly pesticide use.
• Proper sewage treatment and exploration of eco-friendly wastewater treatment options.
• Cut down on industry and manufacturing waste and contain landfills so they don’t spill into the ocean.

Oceans are resilient, but not indestructible. If they’re to last for generations to come, humans must work together to reduce pollution and its impact. The best way to fight ocean pollution is to educate yourself on its causes and make small changes at home to reduce your carbon footprint. It’s never too late to work to improve the ocean’s health.