ocean waves with garbage plastic and human waste washing up and polluting the shore.
June 9, 2023

Water Pollution: Causes and Possible Solutions

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f you’ve ever seen an image of a sea lion or a dolphin caught in plastic waste, you’ll know that water pollution represents a real threat to marine life and wild habitats. However, the effects of water pollution can also seriously affect humans, with unsafe water responsible for more deaths over the past century. To highlight the scale of the crisis, we’ve put together a comprehensive guide to the causes of water pollution and how we can work toward rejuvenating our precious oceans.

Table of  Contents

Why water pollution is a real problem

Water pollution is a multi-faceted problem that encompasses the following issues:

1. Overfishing

Two fishermen dumping large amounts of fish from fishing net onto table.

Consumer demand for fish is at an all-time high. As such, the fishing industry is catching far more fish than is actually consumed and nature can sustain, disrupting marine ecosystems and generating significant quantities of plastic pollution. Many fish nourish themselves by eating phytoplankton and other marine microorganisms. As such, phytoplankton will grow uncontrollably with fewer fish in the water, allowing algae to bloom and produce toxic substances that can harm people, fish, marine mammals, and birds.

Overfishing contributes to the issue of plastic pollution as those responsible for catching fish often leave nets, lines, and traps in the water. Plastic equipment poses the threat of injury and suffocation to wildlife that may get tangled in it. Animals may also ingest fishing tools while mistaking them for food, resulting in digestive issues. Plastic also degrades water quality as its toxic compounds break down, posing risks to human health and wildlife. Finally, it’s worth noting that plastic can disrupt natural water flows and worsen bank erosion.

2. Shark finning

shark fin protruding out of water surface.

Shark finning is a practice which involves removing sharks’ fins to produce shark fin soup – a popular delicacy in southeast Asian regions. As apex predators, sharks sit at the top of the food chain and play a vital role in regulating the populations of smaller fish species. These smaller fish species tend to keep coral reef and seagrass habitats in balance, ensuring that organisms are evenly distributed throughout the water. Shark finning depletes shark populations, throwing ocean ecosystems into disarray. You can find more information on how to help stop shark finning here.

3. Ocean acidification

Illustration of the rise chemicals from industrial activities into air.

Ocean acidification occurs when oceans absorb carbon dioxide,  released by the burning of fossil fuels. This increased absorption lowers the pH of the water, making it more acidic. In turn, organisms such as corals and oysters that produce hard skeletons and shells start to dissolve, and certain fish become less able to detect predators. These issues can disrupt the entire marine ecosystem.

4. Dying coral reefs

Dying and therefore bleached coral reef.

Coral reefs are brimming with marine wildlife and help to protect coastlines from storms and erosion. They support huge numbers of marine species, including around 4,000 fish species, coral reef plants, and animals. Coral are an important part of the food chain as well as providing home and shelter for marine life. They also help scientists produce drugs that could help people with viruses, bacterial infections, cancer, and other conditions. Unfortunately, rapid acidification and increase in water temperature due to higher carbon content, have resulted in a significant wave of coral reef death, also known as coral bleaching. This threatens the survival of  a large population of marine life and those dependent on it. You can learn more about the extent, and impact of coral reef bleaching, and what can be done here.

5. Dead zones

Green zone in ocean is showing green water harmful algae bloom.

Dead zones represent parts of the ocean that are no longer considered livable for marine life due to very low oxygen levels. Dead zones are primarily caused by the agricultural pollution and sewage that find their way into waterways due to soil erosion. This causes harmful overgrowth of algae that consume a significant amount of the existing oxygen in the oceans. You may find more information about dead zones here.  

6. Mercury pollution

Biomagnification with mercury concentration outline diagram showing gradual contamination from algae, insects, fish to humans.

Mercury leaks into the oceans as an industrial waste product, primarily due to mining and fossil fuel combustion. Mercury is a toxic metal that is harmful to the health of humans, fish and other marine wildlife. The substance accumulates in the tissues of fish, growing in concentration as fish higher up in the food chain such as tuna and sharks consume smaller fish eventually affecting the whole food chain, including humans. Prolonged mercury exposure can damage the kidneys, immune system, liver, and nervous system. It is especially dangerous to unborn fetuses, who may suffer from developmental issues following mercury exposure. The Environmental Working Group( EWG) provides a consumer guide for seafood

7. Plastic soup

Great pacific garbage patch illustration showing 99% of trash is plastic.

 The term ‘plastic soup’ describes all the plastic currently stewing in the ocean, both above and below the surface. Common elements of plastic soup include plastic bottles, shopping bags, and microparticles. This plastic debris can degrade habitats, disrupt food chains, and kill marine wildlife. To make matters worse, plastic can take many hundreds of years to degrade, meaning the world’s plastic soup continues to grow in volume.

As one of the most vital resources for life on Earth, oceans are precious. However, the issues listed here demonstrate they’re treated as dumping grounds for industrial and commercial waste. Without coordinated action, the health of humans and ecosystems is at serious risk.

The main types of water pollutants

Water pollution can come from a wide variety of sources and have different effects on ocean ecosystems. The primary types of water pollution include:

  • Man-made materials - Plastic and Rubber: Man-made waste materials such as plastic and rubber can end up in the ocean if improperly discarded. These materials are not easily broken down and may settle at the bottom of bodies of water, harming marine wildlife and depositing toxic chemicals into supplies of fresh drinking water. Alternatively, man-made materials can float on the surface of the water, preventing vital sunlight and oxygen from penetrating the water.
  • Oil: Oil spillages can quickly spread across the surface of the water, smothering the feathers of seabirds and reducing how much sunlight and oxygen aquatic plants receive.Accidental oil spills represent a major source of water pollution and are often caused by botched drilling operations or shipping accidents.
  • Chemicals: Industrial activity can produce a variety of toxic chemicals that sometimes end up in the ocean. Common chemicals include fertilizers, pesticides, pest control substances, metals, and industrial solvents. Industrial farming practices involve the use of these chemicals to protect crops from insects and microbes, and ensure fast growth. Following periods of heavy rain, these chemicals can flow into streams, rivers, and oceans. Industrial sites such as mines, agricultural sites, and manufacturing plants produce toxic chemical waste that require close management. Last but not least, radioactive waste requires close monitoring and proper disposal. When accidents occur at nuclear power plants, harmful radioactive material can enter the water systems. Coal and gas plants can produce similarly harmful chemicals.
  • Thermal pollution: Heat is considered a form of water pollution, as it inhibits the amount of dissolved oxygen water can hold, posing a threat to life forms that require oxygen to survive while encouraging the growth of dead zones. Over time, thermal pollution can also alter chemical balances in marine ecosystems, increasing the rate of fish metabolisms, damaging larvae, and boosting rates of disease. Increasing ocean temperatures results in the endangerment of species that are not able to adapt to the rate of temperature increase as rapidly. Mass die-offs can further pollute the water and upset the balance of marine ecosystems.
  • Biological material: This pollution involves the release of harmful pathogens or other microorganisms into bodies of water from improper handling of sewage and wastewater.

A few sobering statistics about water pollution

It can be tricky to grasp the scale and severity of the world’s water pollution problem. However, the following statistics should provide an overview of the challenges we currently face:

  • Around 14 million tons of plastic enter the ocean every year, contributing to around 80% of marine debris.
  • By 2050, the amount of plastic in the ocean is set to outweigh the biomass of fish.
  • Around 1.2 trillion gallons of untreated water and industrial waste enter US waters every year.
  • Over 3.5 million people die from water-related illnesses every year.
  • Fishing gear and other waste materials harm over 800 different species of aquatic wildlife.
  • Industry pumps around 300-400 MT of waste products into bodies of water annually, including heavy metals, toxic sludge, and industrial solvents.
  • Shark finning kills around 100 million sharks every year.
  • Overfishing has eliminated over 70% of shark populations over the past 50 years.
  • Recent estimates suggest the world’s oceans could be almost free of fish by 2048 if nothing changes.
  • Around half of marine life is thought to be affected by ocean acidification.
  • Since 2009, the world has lost about 14% of its coral.

Realistic solutions to water pollution

Volunteers picking up trash at seaside.

While water pollution may seem like a scary issue, the good news is there are many solutions available to help us restore ocean health. These include:

1. Reduction in plastic waste

Reducing the amount of plastic we produce globally would significantly reduce the amount of plastic that ends up in the ocean. This step would involve finding biodegradable packaging materials and plastic alternatives wherever possible. Another helpful solution would be to improve our management of waste plastic, ensuring that as much plastic as possible is recycled and reused. Governments around the world must invest in improved recycling systems and impose restrictions on companies’ use of plastic. Individual consumers can also do their bit by recycling properly and avoiding single-use plastics wherever possible.

2. Improved sewage treatments

Treating sewage before it enters oceans will help to reduce chemical and biological pollution. Many countries that suffer from wastewater dumping lack the economic resources necessary to invest in water treatment facilities. As such, richer and poorer nations must work together to create collaborative solutions to current ecological issues. Individuals can also reduce problems surrounding wastewater pollution by avoiding flushing objects down the toilet that could block sewage systems. Common culprits of blockages include plastic wrappers, makeup wipes, and sanitary items.

3. Green agriculture

Farmers and agricultural companies can reduce their impact on the ocean by avoiding the use of harmful pesticides and preventing rain runoff by planting trees and other plants close to large bodies of water.

4. Improved handling of industrial wastewater

Manufacturing plants and other industrial facilities can combat water pollution by investing in cutting-edge water treatment and cooling systems. Unfortunately, many companies continue to utilize poorly maintained systems and may lack coherent safety protocols. Governments can aid this process by instating stricter regulations surrounding wastewater management and providing financial incentives for companies to improve their environmental systems.

5. Environmental protection laws

Environmental laws such as the Clean Water Act ensure people stick to anti-pollution principles and continue to protect the ocean. Current laws should be tightened for the best effect, with specific rules for schools, local councils, hospitals, and certain industrial sectors.

6. Campaigns and education

Individuals can make a big difference to their local environment, especially when they’re properly educated about the effects of pollution. As such, education campaigns and ecological advocacy could make a big difference in the health of our oceans and waterways. Key topics to cover could include how to dispose of electrical and chemical waste, how to make more environmentally conscious purchasing decisions, and the dangers of leaving litter on beaches and riversides.

7. Filtration systems

Innovative filtration systems can help to clean up existing pollution and help the ocean regain its former health. While these technologies may be expensive at the moment, investments in research and development could help produce cheap, sustainable technological solutions that work in the long term.

What Can You Do?

As you can see,  ensuring the health of our oceans is crucial in ensuring the wellbeing of the current of future life on earth. Thankfully there are many empowering and rewarding ways to be involved in making a difference. 

As an individual or a household, you have the power to start taking steps from your home. You can start by practicing circular consumption, reducing your plastic consumption, repurposing and recycling wherever possible, educating others. 

You can also advocate for ocean health by supporting non-profits that are already taking action to ensure the recovery and health of our oceans and raising awareness.