Ocean Pollution: Definition, Causes, And Effect

What is Ocean Pollution/Marine Pollution?

Ocean pollution is widespread, worsening, and poses a clear and present danger to human health and wellbeing. But the extent of this danger has not been widely comprehended until now. Our recent study provides the first comprehensive assessment of the impacts of ocean pollution on human health.

Ocean pollution is a complex mixture of toxic metals, plastics, manufactured chemicals, petroleum, urban and industrial wastes, pesticides, fertilizers, pharmaceutical chemicals, agricultural runoff, and sewage.

More than 80% arises from land-based sources and it reaches the oceans through rivers, runoff, deposition from the atmosphere, where airborne pollutants are washed into the ocean by rain and snow and direct dumpings, such as pollution from wastewater treatment plants and discarded waste.

Ocean pollution is heaviest near the coasts and most highly concentrated along the coastlines of low-income and middle-income countries.

Ocean pollution can also be found far beyond national jurisdictions in the open oceans, the deepest oceanic trenches, and on the shores of remote islands. Ocean pollution knows no borders.

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Ocean Pollution

Where does pollution come from?

Most of the pollutants entering the ocean come from human activities along the coast and far inland. One of the largest sources of pollution is non-point source pollution caused by runoff.

Pollution from nonpoint sources can come from many sources, e.g. from septic tanks, vehicles, farms, livestock farms, and timber harvesting areas. Pollution from a single source, such as oil or chemical pollution is referred to as point pollution.

Point source pollution incidents often have a large impact, but fortunately, they do not occur as often. Discharge from faulty or damaged factories or water treatment systems is also considered spot pollution.

Nutrients and algal blooms: Too much of a good thing?

Sometimes it is not the type of material but its concentration that determines whether a substance is a pollutant. For example, the nutrients nitrogen and phosphorus are essential elements for plant growth. However, if they are too common in a body of water, they can stimulate algae overgrowth and trigger an event known as an algal bloom.

Harmful algal blooms (HABs), also known as “red tides,” grow rapidly and cause toxic effects that can affect marine life and sometimes even humans. Excess nutrients released into a body of water through natural or human activities can also lead to hypoxia or dead zones.

When large amounts of algae sink and decompose in the water, the decomposition process uses up oxygen and depletes supplies of healthy marine life. Many of the marine species living in these areas either die or leave the area when they are mobile (e.g. fish).

Using ecological forecasting, NOAA can predict changes in ecosystems in response to HABs and other environmental factors. These projections provide information about how people, economies and communities can be affected.

For example, the Harmful Algal Bloom Monitoring System developed by NOAA’s National Centers for Coastal Ocean Science provides information to the public and local authorities to help decide whether beaches need to be closed temporarily to protect public health.

Fact About The Ocean Pollution

  1. Oil spills aren’t the big(gest) problem: Oil spills make up only 12 percent of the oil in our oceans. Three times as much oil is carried to the sea via drains from our roads, rivers, and drainpipes. if you don’t know about oil spills check our article: what is oil Spills?
  2. More plastic than fish: Eight million tons: that’s how much plastic we throw into the oceans every year. That’s roughly 17.6 billion pounds, or the equivalent of nearly 57,000 blue whales a year. By 2050, ocean plastic will outweigh all fish in the ocean.
  3. 5 garbage patches: There is so much junk at sea that the debris has created huge patches of rubbish. There are five of them around the world, and the largest, the Great Pacific Garbage Patch, contains an estimated 1.8 trillion pieces of garbage and covers an area twice the size of Texas.
  4. Plastic poses a double danger: Ocean trash can be broken into smaller pieces known as microplastics by exposure to sunlight and the impact of waves. Then it can get into the food chain. When it eventually degrades (which for most plastics takes 400 years), the process releases chemicals that further contaminate the ocean.
  5. China, Indonesia top the trash tally: More plastic in the ocean comes from China and Indonesia than anywhere else combined. They make up a third of plastic pollution. In fact, 80 percent of plastic pollution comes from just 20 countries, including the United States.
  6. Pollution is in fashion (literally): With every load of laundry, more than 700,000 synthetic microfibres are washed into our waterways. In contrast to natural materials such as cotton or wool, these plasticized fibers do not decompose. One study showed that synthetic microfibers make up 85 percent of all beach trash.
  7. Most ocean trash sits on the bottom: As unsightly as marine pollution is, what we can’t see can be worse: 70 percent of marine trash actually sinks to the ocean floor, which means we can probably never get rid of it.
  8. Even nutrients can become harmful: When agricultural nutrients such as nitrogen are dumped at sea in large quantities, they can stimulate the explosive growth of algae. As the algae decompose, oxygen is consumed in the surrounding waters, creating a huge dead zone that can lead to the mass deaths of fish and other marine life.
  9. The number of dead zones is growing: In 2004, the scientists counted 146 hypoxic zones (areas with such a low oxygen concentration that animal life suffocates and dies) in the world’s oceans. By 2008, that number rose to 405. In 2017, oceanographers discovered a dead zone in the Gulf of Mexico that was almost the size of New Jersey, the largest dead zone ever measured.
  10. The oceans are losing mussel mass: One effect of greenhouse gas emissions is increased ocean acidification, making it harder for clams like clams, clams, and oysters to form clams, reducing their chances of survival, disrupting the food chain, and affecting the multi-billion dollar mussel industry.
  11. We’re making a racket down there: Noise pollution from shipping and military activities can cause cellular damage to a class of invertebrates, which include jellyfish and anemones. These animals are an important source of food for tuna, sharks, sea turtles, and other creatures.

Causes of Ocean Pollution

The causes of ocean pollution are many. Of all facts there is one constant: most of the pollution in our oceans begins on land and is human-caused. Here are some of the main causes of marine pollution:

1. Nonpoint source pollution (Runoff)

Pollution from nonpoint sources comes from different locations and sources. The result is runoff that occurs when rain or snow carries pollutants from the ground into the ocean. For example, after a violent rainstorm, water spills from roads into the ocean and takes oil from cars onto the roads.

2. Intentional discharge

Manufacturing facilities in some regions of the world release toxic waste, including mercury, into the ocean. While wastewater is purposely dumped into the sea, it also contributes to ocean pollution and plastic products. According to the Ocean Conservancy, eight million tons of plastic enter our oceans every year.

3. Oil spills

Ships and platforms release large amounts of oil every year. However, oil isn’t the only pollutant coming from ships, which can also dispose of fuel, plastic, and human waste. Crude oil is difficult to purify. It’s also poisonous, asphyxiating, and devastating to marine life. Crates lost in storms, accidents and other emergencies also pollute the ocean.

Ships also cause noise nuisance and disrupt the balance of life for marine animals such as dolphins and whales that use echolocation.

Read more about: What is oil Spills?

4. Atmospheric pollutants

Different types of pollutants can get into the water through the rain. A particular threat is carbon dioxide, which has accumulated with climate change. The oceans absorb the excess and become more acidic. This was particularly problematic for calcium carbonate structures like corals, which cannot regenerate or regrow.

Around a million species depend on thriving coral habitats. In addition, the excess CO2 can dissolve the shells of various marine animals.

5. Ocean mining

Deep-sea ocean mining causes pollution and disruption at the lowest levels of the ocean. The ocean floor is a valuable source of gold, silver, copper, and zinc, but underground mining is a major source of pollution.

Sulfide deposits created when drilling these substances can have environmental impacts that are not fully understood. Material leaks and equipment corrosion only exacerbate the problem.

Effects of Ocean Pollution

Ocean pollution has many consequences that directly and indirectly affect marine life and humans. Here are some of the most common marine pollution effects:

1. Harmful to marine animals

Marine animals are frequent victims of ocean pollution. For example, oil spills displace and suffocate marine animals by penetrating their gills. If the oil gets into sea bird feathers, they may not be able to fly or feed their young. Animals that are not killed by crude oil can suffer from cancer and behavior changes and can no longer reproduce.

Marine animals also mistake small pieces of plastic for food, get caught in plastic bags and discarded fishing nets, or are strangled by them. Animals most susceptible to damage from plastic waste in the ocean include dolphins, fish, sharks, turtles, seabirds, and crabs.

2. Depletion of oxygen in seawater

Since excess deposits in the ocean slowly degrade over many years, oxygen is used, which results in less O2 in the ocean. Low oxygen levels in the ocean lead to the death of marine animals such as penguins, dolphins, whales, and sharks.

Excess nitrogen and phosphorus in seawater also cause oxygen starvation. If there is a severe lack of oxygen in one area of the ocean, it can become a dead zone where no marine life can survive.

3. A threat to human health

Pollutants in the ocean are returning to humans. Small organisms ingest toxins and are eaten by larger predators, much of which is seafood that we eventually eat. When the toxins from contaminated animals build up in human tissues, it can lead to long-term health conditions, cancer, and birth defects.

7 Ways To Reduce Ocean Plastic Pollution Today

One of the reasons plastic pollution is such a problem is because it doesn’t go away: “Plastics are forever.” Instead, plastic waste simply breaks down into smaller and smaller particles, so-called microplastics, the environmental impact of which is still being determined.

Solution of Ocean Pollution

Everyone can do something to reduce the amount of plastic that goes into the ocean, and millions of people around the world are already taking steps to reduce their plastic use. Here are seven ways you can make a difference starting today.

Read More about: What is plastic pollution?

1. Reduce Your Use of Single-Use Plastics

Wherever you live, the easiest and most direct way to get started is to reduce your own consumption of single-use plastics. Single-use plastics include plastic bags, water bottles, straws, cups, utensils, chemical cleaning bags, removable containers, and any other plastic item that is used once and then thrown away.

The best way to do this is to a) reject unneeded single-use plastics (e.g., straws, plastic bags, removable utensils, removable containers) and b) buy and carry reusable versions of these products, which includes reusable grocery bags, Bags, bottles, utensils, coffee cups and garment bags for dry cleaning. And if you turn down plastic single-use items, help businesses by letting them know to offer alternatives.

2. Recycle Properly

This should go without saying, but if you are using single-use plastics (and others) that can be recycled, you must always recycle them. Currently, only 9% of the world’s plastic is recycled. Recycling keeps plastics out of the ocean and reduces the amount of “new” plastic in circulation. It is also important that you check with your local recycling center to see what types of plastic they accept.

3. Participate In (or Organize) a Beach or River Cleanup

Help remove plastic from the ocean and prevent it from getting there in the first place by attending your local beach or waterway, or organizing remediation. This is one of the most direct and profitable ways to tackle plastic pollution in the oceans.

You can just go to the beach or the waterway alone or with friends or family and collect plastic waste, or you can join a local organization or international event like the International Coastal Cleanup to clean up.

4. Support Bans

Many communities around the world have bans on single-use plastic bags, take-out containers, and bottles. You can support the adoption of such guidelines in your community. Here is a list of resources for legislators looking to restrict the use of plastic bags.

5. Avoid Products Containing Microbeads

Tiny plastic particles called “microspheres” have become a growing source of plastic pollution in the oceans in recent years. Microspheres are found in some facial scrubs, toothpaste, and body washes and easily find their way into our oceans and waterways through our sewer systems and affect hundreds of marine species.

Avoid products that contain plastic microspheres by searching for “polyethylene” and “polypropylene” on the ingredient labels of your cosmetic products (a list of products with microspheres can be found here).

6. Spread the Word

Stay up to date on issues related to plastic pollution and make others aware of the problem. Tell your friends and family how they can be part of the solution, or throw a party for one of the many documentaries that focus on plastic pollution like A Plastic Ocean, Garbage Island: An Ocean Full of Plastic, Bag It, Addicted to plastic, plassified or garbage island.

7. Support Organizations Addressing Plastic Pollution

There are many non-profit organizations working in various ways to reduce and eliminate plastic pollution from the oceans, including the Oceanic Society, the Plastic Pollution Coalition, 5 Gyres, Algalita, the Plastic Soup Foundation, and others.

Read More about: What is plastic pollution?

These organizations rely on donations from people like you to continue their important work. Even small donations can make a big difference!


What is Ocean pollution?

Ocean pollution is a complex mixture of toxic metals, plastics, manufactured chemicals, petroleum, urban and industrial wastes, pesticides, fertilizers, pharmaceutical chemicals, agricultural runoff, and sewage. Ocean pollution knows no borders.

What is the cause of ocean pollution?

Ocean pollution is caused by the introduction of toxic materials and harmful pollutants such as agricultural and industrial waste, chemicals, oil spills, and plastic litter into the ocean waters.

What are the effects of ocean pollution?

Pollutants in the ocean make their way back to humans. Small organisms ingest toxins and are eaten by larger predators, many of which are seafood that we eventually eat. When the toxins in contaminated animals get deposited in human tissue, it can lead to long-term health conditions, cancer and birth defects.

What are the interesting facts about ocean pollution?

Three times as much oil is carried out to sea via runoff from our roads, rivers and drainpipes. More plastic than fish. Eight million metric tons: That’s how much plastic we dump into the oceans each year. That’s about 17.6 billion pounds or the equivalent of nearly 57,000 blue whales every single year.