Ocean Pollution – 6 Things That Make It Worse

The oceans and seas cover 70% or two-thirds of our planet’s surface and are vital for sustaining life on Earth. They are responsible for many natural processes like rain and climate regulation, not to mention the millions of species that call them home. They also allow us to conduct maritime trade and connect economies across the world.

However, humans have wreaked havoc on oceans by overfishing and dumping all kinds of waste into the waters.  Accidents such as the BP oil spill and Samarco dam collapse are striking instances of how badly human activities can destroy the rich marine ecosystem.

Causes of Ocean Pollution

Ocean pollution is caused by many human activities some of which are described below.

1. Ocean Dumping

Also known as marine dumping, this includes the deliberate disposal of garbage including waste from factories or industries, all kinds of ships, sewage, waste from aircraft, offshore platforms etc into the oceans. This not only pollutes the water but also degrades habitats of marine species. It can lead to coastal erosion and impact the health of the aquatic ecosystem.

This happens because industrial waste contains hazardous materials like cryolite, DDT, mercury and even radioactive materials.

Ballast water from ships can introduce harmful organisms into new environments which can become invasive in the new area. Also, treatments for ballast water like electrochemical treatment, chlorination etc can create disinfection by-products which have negative effects on mammals. The BWM Convention was adopted in 2004 to control the transfer of invasive species through ballast water from ships.

2. Land Runoff

Most water from land sources ends up in oceans. The water evaporates from the ocean, leaving the salt behind and then forms clouds which fall as rain. Pesticides, fertilisers and oil from land seep into the ground after rainfall and enter rivers and oceans.

This encourages the growth of algal blooms which clog waterways and lead to the death of seagrass meadows, kelp beds and ecosystems due to lack of oxygen. An area without any life is called a dead zone and can be massive, like in the coastal zones of Louisiana and Texas. Many bays and estuaries have dead zones due to pollution run-offs. The chemicals from this water reach human beings when they consume seafood, causing cancer, neurological issues and birth defects in babies.

There are over 400 hypoxic zones ( areas with low oxygen) in the oceans. In 2017, scientists found a dead zone, the size of New Jersey in the Gulf of Mexico, said to be the biggest dead zone ever measured at that time.

3. Oil Spills

Spilling of oil from tankers and offshore rigs in the ocean is another cause of sea pollution. Oil spills from tanker ships after accidents, including Deepwater Horizon, the Gulf War oil spill and the Atlantic Empress, have shown us the damage the spills can do to the ecosystems.

Oil spills are not only catastrophic for marine life, and sea birds but also for communities living near coastal areas. Oil contaminates sediments, has toxic effects on aquatic life, destroys habitats and kills fish, damages economies of coastal communities dependent on fishing, impacts shipping as a route experiencing a spill might be closed temporarily and lastly, blocks sunlight which kills plants growing in water. It can also contaminate drinking water sources and kill seabirds whose feathers get covered with thick slick, preventing them from flying.

4. Littering

Litter items like fishing lines, hooks, plastic etc can trap pelicans and other seabirds, which can strangle them. Whales, dolphins and other mammals can ingest or get entangled in plastic that is thrown on beaches and finds its way into the oceans.

Even turtles can ingest plastic bags, confusing them for their food, which is jellyfish. This is affecting the world’s largest turtles, the leatherback turtles which are found off the coasts of the Atlantic and Pacific. Once swallowed, the plastic bags clog the intestines, leading to the death of the turtles.

The latest research shows that in Alaska each year, around 30,000 northern fur seals get entangled in plastic debris and die. Marine debris can damage the engines of boats by clogging intake valves and getting tangled around propellers.

There are five massive garbage patches in the oceans, the largest being the Great Pacific Garbage Patch — which includes around 1.8 trillion pieces of trash and spans an area twice the size of Texas.

5. Ocean Mining

Mining under the ocean for silver, gold, copper, cobalt, etc. is another source of ocean pollution. Mines, where ores are drilled thousands of meters down, dispose of their wastes in the ocean, creating disastrous impacts on the marine life on the seabed.

Researchers, with limited scientific evidence, suggest that such activities increase the toxicity, which will eventually put the ecosystem in the area under threat.

6. Noise Pollution

Besides these reasons, the aquatic life in the sea is also disturbed by several other factors. Recent studies have proved that the increasing noise pollution in the sea also threatens marine life. It can create stress for marine mammals like dolphins, whales etc and disrupts their breeding and feeding patterns. Noise from ships also hampers the communication between dolphins.

In addition to the increased traffic, the loud sounds from sonar devices and oil rigs make the situation worse.

Effects of Ocean Pollution

The wastes dumped into the oceans tend to have toxic substances, which soak in all the oceanic oxygen. This leads to a marked depletion of oxygen available to mammals and other fish causing them to die in their natural habitat.

Every year, according to reports, more than one million seabirds are being killed by ocean pollution. In addition, thousands of dolphins and porpoises are dying every year due to increased human intervention.

The increased presence of plastic on the ocean surface has resulted in more serious problems. Since most of the plastic debris that reaches the ocean remains floating for years as it does not decompose quickly, it leads to the dropping of oxygen levels in the water, severely affecting the survival of marine species.

To prevent further degradation of the oceanic environment, several laws and regulations have been enacted.

The London Convention of 1975 is one of the prominent ones, while other laws include the Clear Water Act (CWA) and the Ocean Dumping Act (ODA) which have been established by the United States to tackle the problem of ocean pollution.

Meanwhile, efforts are underway to clean up the mess that pollutes the oceans and its ecosystem. The Ocean Cleanup project, initiated by Dutch-born inventor-entrepreneur Boyan Slat, is attempting to remove plastic wastes from the sea and also prevent more plastic debris from entering the waters.

Started in 2014, the team is researching the total quantity of plastic debris in the oceans, and feasible recycling methods.

You might also like to read:

• Effects of Noise Pollution from Ships on Marine Life
• MARPOL (The International Convention for Prevention of Marine Pollution For Ships): The Ultimate Guide
• 8 Ways Cruise Ships Can Cause Marine Pollution
• Marine Pollution by Ships -Tips for Reducing Recycling Waste at Sea
• 10 Endangered Ocean Species and Marine Animals
• What is Plastic Aquatic Project?

About Author

Zahra is an alumna of Miranda House, University of Delhi. She is an avid writer, possessing immaculate research and editing skills. Author of several academic papers, she has also worked as a freelance writer, producing many technical, creative and marketing pieces. A true aesthete at heart, she loves books a little more than anything else.

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