Oceans make up over 70% of the Earth, but due to harmful human activities, ocean pollution is at its highest today. Pollution is the act of infiltrating the natural environment with toxins and hazardous substances, and the ocean is being contaminated through numerous channels.
Understanding sea pollution and its causes is an important step towards preventing it There are various types of ocean pollution that most people are not aware of. Here is a list of types of ocean pollution and how they affect life on earth:
This is one of the biggest reasons behind increasing sea pollution. Industrial waste is a vast category of pollutants. It consists of harmful chemicals, metals, radioactive wastes, and plastic pieces, that can be a great threat to humans as well as organisms existing within the sea.
● Metal Pollution
Industrial waste is the biggest source of metal pollution in the sea. The most common metals among these are mercury and lead – both of which are extremely dangerous for humans and marine life. Lead is mostly known for contaminating the water while mercury accumulates the fish, harming them as well as becoming a threat to people who consume them.
● Plastic Pollution
Plastic pieces are one of the biggest constituents of industrial waste. Since plastic does not decompose, neither in water nor on land, plastic that finds its way to the ocean accumulates on the sea bed and contaminates the water. Moreover, plastic pieces are extremely harmful for fish and small organisms because they get stuck on their bodies, causing them to lead painful life.
Furthermore, microplastics, that are added to plastics for their flexibility and color, are also hazardous materials. Microplastics contain harmful toxins that can be life-threatening toward sea organisms as well as human beings, who may come in contact with them.
● Chemical Pollution
There are various types of hazardous chemicals present in industrial waste. Most of the time, chemicals seep into the ground and travel through rivers and streams to eventually reach the ocean – penetrating and contaminating all forms of water bodies coming in its way. Chemicals tend to enter the food chain, affecting marine organisms and human beings who consume them.
Nutrient pollution occurs when there is an increase in nutrient composition in water. Agricultural waste is the biggest reason behind nutrient pollution. Fertilizers, pesticides, and herbicides used by farmers contain nutrients like phosphorus and nitrogen that enter seawater. An increase in nutrient levels, especially phosphorus, causes Eutrophication.
Eutrophication is a phenomenon where increased nutrients reduce oxygen levels in the water and lead to the formation of Harmful Algal Blooms on the water surface. This creates “dead zones” in the water. Dead zones are areas in the sea that are oxygen-deficient, receive no sunlight, and lack marine life. This is becoming a rising problem across the world, all due to nutrient pollution.
Oil pollution poses serious harm to life existing in seawater. The oil that enters the sea can suffocate fish and accumulate their body, hindering their ability to swim and breathe through their gills. Moreover, oil on the water surface blocks sunlight making it difficult for plants to photosynthesize.
Oil pollution is caused by two reasons. The most common one is large-scale oil spills. Ships that travel in the sea often release fuel or can spill large amounts of oil into seawater, in case of an accident or leakage.
The second type is oil from vehicles. Fuel on the streets which comes from leaky vehicles finds its way to the ocean due to surface runoff. Surface runoff occurs in cases of heavy rains, where rainwater carries pollutants like oil from the streets to the sea.
Carbon Dioxide Pollution
Carbon dioxide is a harmful gas that harms both humans and marine animals. The burning of fossil fuels is a major reason behind the rising Co2 concentration in the atmosphere. This Co2 gets absorbed and dissolves in the water, changing its pH levels. Due to changes in pH levels, sea waters are now becoming more and more acidic – making them unsuitable for marine animals to survive in.
This is a type of ocean pollution that is highly underrated. Swimmers and divers wear sunscreens which washes off into the sea, contaminating ocean waters. Sunscreens are mostly made up of chemicals like oxybenzone, which can be harmful to organisms like sea urchins and mammals living in the sea.
Moreover, organic sunscreens are also dangerous for small marine invertebrates. They contain organic plant-based oils like lavender, neem, and eucalyptus oils – all of which possess insect repellent properties.
This is another underrated type of ocean pollution. We humans do not understand the harmful effect of building cities closer to coastal areas. Human habitation at the coast means the presence of artificial light near the sea, especially at night. This disrupts the natural daily routine of marine animals.
Fish have a natural circadian rhythm that they follow every day. This gets disrupted due to the presence of light at night. This can affect their reproductive cycle and disturb the overall food chain present in the sea.
Noise pollution is not only an issue on land, it is even more harmful to organisms living in the sea. Building metropolitan cities around coastal areas is a major reason for noise pollution in the ocean. Other reasons like rigging, mining, industrial activities, and construction near the sea all cause serious noise pollution in the ocean.
Sounds waves travel deep down to the sea bed. These vibrations confuse animals and disturb their natural food and reproductive cycle. Most animals that depend on “sonar signals” find it difficult to navigate, prey, and mate underwater – reducing their lifespan. This is a serious threat to marine species that are on the verge of extinction.
Oceans cover over two-thirds of the earth’s surface and play a vital role in the existence of all life forms on this planet. Pollution of ocean water has a direct negative impact on humans, animals, and the entire ecosystem.
As a citizen of this planet, it is our responsibility to combat this issue. Now that we have understood the different types of ocean pollution, it will be easier for us to reach its root cause, help prevent it and clean up the environment.
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