Chemicals and debris, the majority of which come from terrestrial sources and are washed or blown into the ocean, make up marine pollution. Pollution harms the environment, the health of all organisms, and economic structures all over the world. Waste from marine debris, plastic pollution, including microplastics, ocean acidification, nutrient pollution, poisons, and underwater noise are all examples of marine pollution. This article will explain to you about Marine Pollution (Ocean Pollution) which will be helpful in preparing the Environment syllabus for the UPSC Civil service exam.

Marine Pollution - Causes

Direct Discharge

• Pollutants are directly discharged from cities or factories into rivers, and if those rivers flow into the sea, the hazardous or toxic wastes will end up in the oceans.
• Mining for minerals such as iron, copper, and zinc contributes significantly to marine pollution.
• Uprooted soil usually ends up in rivers that flow to the oceans. That is not a problem in and of itself, but the minerals that are mined will be a source of concern because their effects can be toxic to marine life.

Plastics

• Plastics are a significant component of the hazardous wastes that are directly discharged into the oceans.
• Between 4 and 12 million metric tonnes of plastic are dumped into the ocean each year.
• Every year, India produces 62 million metric tonnes of waste, of which 10-12 percent is plastic waste, including single-use plastics.
• They inturn greatly serve as the cause for marine pollution.
• China, Indonesia, Sri Lanka, Vietnam, Egypt, Thailand, and Nigeria, according to environmental studies, are major contributors to ocean plastic pollution.

Sewage

• Sewers or contaminating substances run straight into the ocean through sewage, rivers, or drainages.
• In India, 80 percent of municipal sewage is collected, but only 20% of it is cleaned before being dumped directly into the oceans.

Toxic Chemicals from Industries

• Another prominent type of waste that is directly thrown into the oceans is industrial and agricultural waste which causes severe contamination.
• Toxic liquids dumped in the ocean have a direct impact on marine life.

Land Runoff

• Another source of pollution in the water is runoff from the land.
• When water infiltrates the soil to its maximum capacity and extra water from rain, flooding, or melting runs over the land and into the ocean, this occurs.
• This water frequently picks up harmful man-made chemicals that end up in the ocean, such as fertilisers, petroleum, pesticides, and other soil toxins.
• Plastic garbage accounts for 80 percent of land discharge into the sea.
• Polluted run-off from highways and roads can be a major source of water pollution in coastal areas.

Oil Spills

• Ship pollution is a major source of ocean pollution, with oil spills being the most severe effect.
• Crude oil can linger in the sea for years and is exceedingly hazardous to marine life, often smothering them to death once entrapped.
• Crude oil is also incredibly difficult to clean up, which means that once it has been divided, it usually stays split.
• Every year, over 706 million gallons of waste oil pollute the water, according to Marine Insight.

*To know more about the topic, click this link Oil Spills

Ocean Mining

• Another source of contamination in the water is deep sea mining.
• Ocean mining sites that drill for silver, gold, copper, cobalt, and zinc develop sulphide deposits up to 3,000 meters below the surface on an average thereby causing marine pollution.
• Leaks, spills, and corrosion will change the ecological makeup of the mining area.

Atmospheric Pollution

• Pollution from the atmosphere is a significant source of marine pollution.
• This happens when objects from far inland are blown large distances by the wind and end up in the ocean.
• These particles can range from natural materials such as dust and sand to man-made materials like garbage and rubbish.
• The majority of waste, particularly plastic debris, is incapable of decomposition and remains floating in the ocean's current for years.
• During the warm season, dust from the Sahara, for example, moves around the southern periphery of the subtropical ridge and into the Caribbean and Florida as the ridge builds and moves northward through the subtropical Atlantic.
• Climate change raises ocean temperatures over time, causing carbon dioxide levels to rise and altering marine ecosystems and fish distributions. This has had an impact on communities that rely on fisheries.

Causes of Marine Pollution

Types of Marine Pollution

Marine Debris Pollution

• Marine debris, often known as marine litter, is human-made rubbish that has been thrown into a sea or ocean, either intentionally or accidently.
• Floating maritime debris is known as beach litter or tidewrack when it accumulates in the middle of gyres and along coastlines, usually washing ashore.
• Ocean dumping is the deliberate discharge of garbage at sea. Driftwood and drift seeds are examples of naturally occurring detritus.
• Because many forms of (petrochemical) plastics do not biodegrade as quickly as natural or organic materials, human influence has become an issue as the use of plastic has increased.

Plastic Pollution

• The accumulation of synthetic plastic items in the environment to the degree where they cause difficulties for wildlife and their habitats, as well as human populations, is known as plastic pollution.
• Plastics have become persistent organic pollutants (POPs) in several environmental niches by the end of the twentieth century, from Mount Everest to the ocean's depths.
• In other words, plastic pollution is the accumulation of manufactured plastic goods in natural settings that harms humans and wildlife.
• One of the major contributions to climate change is plastic pollution.
• Plastic is nearly impossible to decompose, and it ends up in landfills and the ocean, harming marine life.

*To know more about the topic, click this link Plastic Pollution

Ocean Acidification

• The intake of carbon dioxide (CO2) from the atmosphere causes ocean acidification, which is the continual reduction in the pH value of the Earth's seas.
• The burning of fossil fuels by humans is the primary cause of ocean acidification.
• The amount of carbon dioxide absorbed by the ocean grows in lockstep with the amount of carbon dioxide in the atmosphere.
• This causes a chain of chemical reactions in the seawater, which has a deleterious impact on the ocean and marine life.
• Ocean acidification will result in a decrease in pH, indicating that the water will become less basic and hence more acidic.
• Ocean acidification can cause a decline in the synthesis of calcium carbonate shells in shellfish and other aquatic life, as well as other physiological problems for marine creatures.
• Many species, particularly oysters and corals, are affected by ocean acidification. It's one of the ocean-related repercussions of climate change.

Nutrient Pollution (Eutrophication)

• Eutrophication is defined as an increase in chemical nutrients in an environment, often nitrogen or phosphorus-containing compounds.
• It can lead to an increase in primary productivity (excessive plant growth and degradation) as well as other negative consequences such as a lack of oxygen and severe declines in water quality, fish, and other animal populations.
• Rivers that pour into the ocean, along with the many chemicals used as fertilizers in agriculture, as well as waste from livestock and humans, are the main culprits.
• Hypoxia and the formation of a dead zone can result from an overabundance of oxygen-depleting compounds in the water.

*To know more about the topic, click this link Eutrophication

Toxins

• Apart from plastics, other toxins that do not degrade quickly in the marine environment pose a specific threat.
• PCBs, DDT, TBT, pesticides, furans, dioxins, phenols, and radioactive waste are examples of persistent toxins.
• Heavy metals are chemical elements with a relatively high density that are hazardous or poisonous in small amounts. Mercury, lead, nickel, arsenic, and cadmium are just a few examples.
• Toxins can build up in the tissues of many aquatic organisms, a process known as bioaccumulation.
• They've also been found in benthic settings including estuaries and bay muds, providing a geological record of human activity from the previous century.

Marine Pollution - Effects

Marine Animals

• The toxic wastes in the marine environment has a harmful effect on marine animals.
• The oil spill poses a threat to marine life in a number of ways.
• The oil spilt in the ocean could get into marine animals' gills and feathers, making it harder for them to move, fly or feed their young ones.
• Cancer, reproductive system failure, behavioral abnormalities, and even death can be long-term effects on marine life.

Coral Reefs

• The oil spill floats on the water's surface affecting coreal reefs and disrupts their cycle of processes.
• The oil spills block sunlight from reaching marine plants and interferes with photosynthesis. Thus, it can disrupt the food chain of other dependent organisms.
• On the other hand the harmful chemicals found in the oil spill can enter the food chain too.
• Long-term effects on marine life include skin irritation, eye discomfort, lung and liver disorders.

Increase in Biological Oxygen Demand (BOD)

• The oil spills floating on the upper surface of water bodies block the sunlight from reaching below. Thus, the aquatic organism’s need of oxygen increases.
• The decomposers such as bacteria too require a lot of oxygen to breakdown the dead matter and to survive.
• This raises the biological oxygen demand, or BOD, in the water body, resulting in hypoxia. This in turn is harmful to aquatic life.
• Biological Oxygen Demand (BOD) also occurs due to eutrophication.

Human Health

• Human health can also be stressed due to marine pollution.
• Animals from the damaged food chain when consumed by humans have an impact on their health because chemicals from these polluted animals are deposited in human tissues.
• These chemicals potentially lead to cancer, birth defects, and long-term health problems.

Marine Pollution - Mitigation

• Limiting off-shore drilling by using renewable energy sources like wind and solar electricity is advisable.
• Pesticides in agriculture should be limited, and organic farming and environmentally friendly pesticides should be encouraged.
• Sewage treatment and investigation of environmentally friendly wastewater treatment options should be done.
• To avoid spills, industry and manufacturing waste should be reduced and should be contained in landfills.
• Biotechnology is being used to treat oil spills through bioremediation (the use of specialized microbes to digest and eliminate toxic compounds).
• Personal carbon footprint should be reduced by living a "green" lifestyle.
• Having a global convention prohibiting the use of single-use plastics and a cooperative effort to clean up the ocean is mandatory.

Global Initiatives to Combat Marine Pollution

Global Programme of Action (GPA)

• The Global Program of Action for the Protection of the Marine Environment from Land-based Activities (GPA) was established as a one-of-a-kind intergovernmental instrument to combat land-based pollution.
• The GPA is also the first global intergovernmental process that specifically addresses the interconnection of terrestrial, freshwater, coastal, and marine ecosystems.
• At an intergovernmental summit in Washington, D.C. in 1995, 108 governments and the European Commission accepted the GPA.
• Governments, in collaboration with other stakeholders, including international and public organizations, local communities, non-governmental organizations, and the commercial sector, implement the GPA.

MARPOL Convention (1973)

• It includes ship pollution of the marine environment due to operational or unintentional reasons.
• It details the numerous types of maritime pollution caused by oil, toxic liquid chemicals, packaged dangerous substances, sewage, and waste from ships, among other things.

The London Convention (1972)

Its goal is to encourage effective regulation of all causes of marine pollution and to take all reasonable actions to prevent pollution of the sea from waste and other materials dumped into it.

Greenpeace

• It is a non-profit organization dedicated to protecting the seas and marine life around the world.
• Because of its grassroots initiatives, damaging fishing techniques have been banned.
• Numerous companies' fishing strategies have changed, and whale sanctuaries have been established.

Conclusion

Oceans are resilient, but they are not invincible. Even some promising techniques for mitigating marine pollution are insufficient. So-called "biodegradable" plastics often only degrade at temperatures well above those found in the ocean. Thus, humans must work together to eliminate pollution and its impact if they are to last for future generations. The most effective strategy to combat ocean pollution is to educate yourself about the reasons and make minor changes at home to lessen your carbon footprint. According to a United Nations study from 2018, more than sixty countries have passed legislation limiting or prohibiting the use of disposable plastic goods.

FAQs

MCQs

1. Which of the following is the most significant contributor to marine pollution?

A) Oil Spills
B) Plastic Waste
C) Agricultural Runoff
D) Chemical Pollutants

2. Which international organization is responsible for reducing marine pollution caused by ships?

A) World Health Organization (WHO)
B) International Maritime Organization (IMO)
C) United Nations Environment Programme (UNEP)
D) International Labour Organization (ILO)

3. What is the major effect of chemical runoff on marine environments?

A) Increased biodiversity
B) Coral bleaching
C) Nutrient overload leading to algal blooms
D) Higher fish populations

4. Which of the following is a major consequence of oil spills in marine environments?

A) Clean-up of beaches
B) Damage to marine ecosystems
C) Creation of artificial reefs
D) Decrease in global temperatures

5. What is the main objective of the Clean Seas Campaign launched by the UNEP?

A) To eliminate plastic waste from oceans
B) To reduce carbon emissions
C) To protect coral reefs
D) To improve fishing practices

GS Mains Questions and Model Answers

Q1: Analyze the causes and consequences of marine pollution on global ecosystems. How can international cooperation address this issue?

Answer: Marine pollution is caused by various factors such as plastic waste, oil spills, industrial discharges, and agricultural runoff. These pollutants harm marine life through ingestion, poisoning, habitat destruction, and the disruption of food chains. Oil spills, for example, can damage sensitive coastal ecosystems, while plastics persist in the ocean, affecting marine animals for decades. The consequences extend beyond environmental harm, impacting global economies through losses in fisheries, tourism, and coastal development. International cooperation is crucial in addressing marine pollution through agreements such as the MARPOL Convention, regional efforts like the Coral Triangle Initiative, and global campaigns like UNEP’s Clean Seas campaign. Collaborative efforts are essential for enforcing stricter regulations, improving waste management, and advancing sustainable practices in both the maritime and industrial sectors.

Q2: Discuss the role of marine pollution in climate change. How do pollutants like plastics and oil contribute to global warming?

Answer: Marine pollution plays a significant role in climate change by contributing to the degradation of marine ecosystems, which are essential in regulating global temperatures. Plastics, particularly microplastics, absorb and release heat, affecting ocean temperatures. Additionally, the decomposition of plastics in the ocean releases greenhouse gases such as methane, which further contribute to global warming. Oil spills, besides harming marine life, can impact the ocean’s ability to absorb carbon dioxide, which exacerbates the effects of climate change. The destruction of coral reefs due to pollution also reduces the ocean’s ability to store carbon, further aggravating the impact of climate change.

Q3: Evaluate the effectiveness of current policies and initiatives aimed at reducing marine pollution. What more can be done to protect oceans and marine life?

Answer: Current policies and initiatives, such as the MARPOL Convention, the Clean Seas Campaign, and regional agreements on marine litter, have made progress in raising awareness and reducing certain types of pollution. However, the effectiveness of these initiatives is limited by enforcement challenges, particularly in developing countries where waste management infrastructure is lacking. To protect oceans and marine life more effectively, it is essential to enhance global cooperation, improve waste management practices, promote the use of biodegradable materials, and establish stronger penalties for illegal dumping. Additionally, fostering research and innovation in sustainable industries and encouraging corporate responsibility can further reduce the pollution load on the oceans.

Previous Year Questions on Marine Pollution

1. UPSC CSE Prelims 2019:

Question: What is the primary impact of marine pollution on coastal ecosystems?

A) Increase in biodiversity
B) Destruction of habitats
C) Rise in ocean temperatures
D) Decrease in fish populations

Answer: (B)

Explanation: Marine pollution primarily impacts coastal ecosystems by destroying habitats, including mangroves, coral reefs, and beaches, which are critical for marine life.

2. UPSC CSE Mains 2021 (GS Paper 3):

Question: "Examine the current international and national efforts to address marine pollution. How effective are these measures in tackling the problem?"

Answer: International efforts such as the MARPOL Convention and the UNEP’s Clean Seas campaign, along with national policies, have raised awareness and made strides in reducing marine pollution. However, challenges such as inadequate enforcement, lack of proper waste management, and limited resources hinder their effectiveness. Strengthening policies, improving waste disposal infrastructure, and fostering global cooperation will be critical to addressing marine pollution effectively.