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What is Marine Pollution?

Christina Edwards
Christina Edwards

Marine pollution refers to ocean contamination, especially with man-made waste or byproducts. This is considered to be a severe problem by many environmentalists, since it can have detrimental and lasting effects on the global marine ecosystem. There are several types of marine pollution, each of which has the potential to harm the delicate balance of life.

A number of sources can generate marine pollution. Sources that directly dump waste into the water are known as point sources. Non-point source pollution is harder to recognize, and therefore harder to regulate. This occurs when pollution comes from several hard-to-pinpoint sources, such as the debris blown into the ocean by gusts of wind.

Plastic bags contribute to marine pollution.
Plastic bags contribute to marine pollution.

Marine debris usually includes plastic litter discarded by humans, either intentionally or accidentally. This marine pollution can be harmful to marine life, such as fish or dolphins. Animals can become tangled up in things like old fishnets or plastic six pack holders, or they can suffocate if they get trapped in a plastic bag. If the debris resembles an animal's food, it could also be ingested, and most likely, the animal will not be able to digest it.

Oil booms being used to limit the spread of an oil spill in the ocean.
Oil booms being used to limit the spread of an oil spill in the ocean.

Garbage and other marine debris sometimes ends up covering the coastlines of islands in the middle of ocean gyres, which are large circulating ocean currents. Hawaii, for example, is in the middle of the North Pacific Gyre. Because of the massive amount of debris found here, it is often referred to as the Great Pacific Garbage Patch. One major source of marine debris is containers that fall off ships, the contents of which end up on shores all over the world.

Containers that fall off ships can contribute to marine pollution.
Containers that fall off ships can contribute to marine pollution.

Ships and other ocean vessels are main contributors to marine pollution. Oil spills can harm marine life and often take months or even years to clean up. These vessels can also introduce non-native species of animals, plants, and micro-organisms to new habitats when they dump their ballast waters. This can lead to an unbalanced ecosystem as these new species prey on and compete with the native species in the area.

A group of fish that has died and floated to the service is one type of marine pollution.
A group of fish that has died and floated to the service is one type of marine pollution.

Ships, large boats, and submarines are also a major source of noise pollution in the oceans and seas. Since sound travels farther in water than it does in air, noises like sonar can travel for miles. This can cause problems in animals that rely on noise to communicate with each other or find prey.

Toxins, such as chemicals, certain metals, and radioactive waste, are another form of marine pollution. These poisonous substances often have harmful effects on marine life and can accumulate in their bodies. Mercury, which is a waste product of certain types of power plants, accumulates in fish. Albacore tuna and swordfish with high levels of mercury are considered unsafe to eat, especially for nursing mothers, pregnant woman, and children.

Marine pollution can be harmful to dolphins.
Marine pollution can be harmful to dolphins.

Chemical nutrients, like nitrogen and phosphorus used in fertilizers, accidentally released into the ocean also contribute to marine pollution. These often make it into bodies of water because of agricultural runoff. Excess amounts of these types of nutrients can cause excessive algae growth. This process, known as eutrophication, can often lead to less oxygen in the water.

The amount of oxygen in the water also decreases as the water gets warmer. This can happen when water that is used as a coolant by industrial manufacturers and power plants is dumped into rivers and oceans. Since the warmer water contains less oxygen, some species find it harder to survive and may die off. This type of marine pollution is called thermal pollution.

Acidification of the world's oceans is another concern of many environmentalists. The ocean naturally absorbs carbon dioxide, and since the amount of carbon dioxide in the atmosphere is increasing, the amount that the ocean is absorbing is also increasing. The result is a lower pH level in the oceans, which can disrupt the delicate marine ecosystem. Many researchers believe more acidic waters can make it harder for some shellfish to form their shells. Disappearing coral reefs are also blamed on ocean acidification.

Frequently Asked Questions

What is marine pollution and how does it affect ocean ecosystems?

Marine pollution refers to the entry of harmful substances such as chemicals, plastics, industrial, agricultural, and residential waste into the ocean, causing detrimental effects on marine life and ecosystems. It disrupts the balance of marine environments, leading to loss of biodiversity, alteration of food webs, and the degradation of habitats. For instance, plastic pollution affects over 800 marine species through ingestion or entanglement, according to the United Nations Environment Programme.

What are the primary sources of marine pollution?

The primary sources of marine pollution include land runoff, industrial discharges, sewage, oil spills, and marine litter, with plastics being a significant contributor. Land-based sources account for approximately 80% of marine pollution, as reported by the National Oceanic and Atmospheric Administration. Activities such as agriculture, manufacturing, and urban development contribute to the runoff that carries pollutants to the oceans.

How does plastic pollution impact marine life?

Plastic pollution poses a severe threat to marine life through ingestion, entanglement, and habitat disruption. Animals often mistake plastics for food, leading to internal injuries, starvation, and death. Entanglement in plastic debris can cause suffocation, drowning, or prevent animals from escaping predators. The United Nations has reported that every year, plastic pollution causes the deaths of more than 1 million seabirds and 100,000 marine mammals.

What are the consequences of oil spills in marine environments?

Oil spills have catastrophic effects on marine environments, coating everything they touch and creating a barrier that prevents oxygen and sunlight from reaching marine organisms. This can result in immediate and long-term ecological damage. For example, the Deepwater Horizon oil spill in 2010 released approximately 4.9 million barrels of oil, causing extensive harm to marine and coastal ecosystems, as per the U.S. Environmental Protection Agency.

Can marine pollution affect human health?

Yes, marine pollution can significantly affect human health. Contaminants like heavy metals and chemicals can accumulate in seafood, leading to foodborne illnesses and long-term health issues when consumed by humans. Additionally, polluted beaches and waters can harbor pathogens, increasing the risk of gastrointestinal, respiratory, and skin diseases. The World Health Organization has highlighted the importance of managing marine pollution to safeguard public health.

What actions can individuals take to reduce marine pollution?

Individuals can help reduce marine pollution by minimizing single-use plastics, properly disposing of waste, participating in beach cleanups, and supporting policies and organizations that protect marine environments. Responsible consumer choices, such as selecting sustainable seafood and reducing chemical usage, also contribute to healthier oceans. Every action counts, as reducing the input of pollutants at the source is crucial for mitigating marine pollution.

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    • Plastic bags contribute to marine pollution.
      By: Africa Studio
      Plastic bags contribute to marine pollution.
    • Oil booms being used to limit the spread of an oil spill in the ocean.
      By: Pshaw-Photo
      Oil booms being used to limit the spread of an oil spill in the ocean.
    • Containers that fall off ships can contribute to marine pollution.
      By: Nickolay Khoroshkov
      Containers that fall off ships can contribute to marine pollution.
    • A group of fish that has died and floated to the service is one type of marine pollution.
      By: Paper Girl
      A group of fish that has died and floated to the service is one type of marine pollution.
    • Marine pollution can be harmful to dolphins.
      By: Aleksandr Lesik
      Marine pollution can be harmful to dolphins.