By David Okul
The marine environment is vulnerable to pollution from various human-made sources. A staggering 80% of all the pollution in the marine ecosystems originates from land. Shipping accidents and oil spills make up the rest of the contamination. In general, the sources of marine pollution include:
- Nutrients– nutrients from sewage, farming, and forestry runoff are the leading contributors to marine pollution. Nutrients are also prevalent in nitrogen oxides from automobiles and power plants. They pollute the marine environment by feeding algal blooms present in coastal waters. Nutrients further play a role in decomposing algae, consequently robbing the water of oxygen and eventually killing marine life. Nutrients spur red tides, producing toxins responsible for poisoning people, and killing fish.
- Sediments– sediments are a result of erosion from farming, mining, forestry, and coastal dredging. They pollute the marine environment by clouding water hence hindering photosynthesis below the surface waters.
- Pathogens– the primary source of pathogens include livestock and sewage. Pathogens contaminate ocean waters and seafood, further spreading typhoid, cholera, and other diseases.
- Plastics– millions of plastics in oceans contribute heavily to marine pollution. The main source of plastics in the marine environment include fishing nets, beach litter, and wastes from the plastic industry. Plastic litter coasts and beaches and they can remain in the ocean water for hundreds of years. Plastic debris is known to entangle marine life, causing deaths and severe injuries. Plastic causes about 60-90% of all pollution in aquatic ecosystems.
- Radioactive substances– these substances come from military waste and a discarded nuclear submarine. They can further originate from industrial wastes and atmospheric fallout.
- Oil–Oil from cars, industries, oil tankers, and heavy machinery accounts for 33% of marine pollution. Oil contamination in the oceans can kill marine life. Tar and other petroleum by-products litter coastal habitats and beaches.
- Noise– Noise from large water vessels such as supertankers also pollutes the marine environment a great deal. Loud noise can be heard miles away underwater. Noise suppresses marine life. It even scares away fish and various types of marine life.
In summary, marine pollution is either caused by trash or chemicals. Of importance is to appreciate the role of plastics in marine pollution. As a significant pollutant, plastics also disintegrate into microplastic, which is consumed by organisms in the oceans. Scientists have not identified with certainty the effects of microplastics.
Effects of marine pollution
The overabundance of marine pollution has adverse consequences. Below are the major implications of marine pollution.
- Kills marine life and jeopardizes human health– pollution leaves debris in the water. The waste is hazardous and chemically harmful. They can kill a wide array of marine life. Courtesy of marine pollution discarded broken glass, plastic and metal cans can harm fish and humans. Trash litters beaches alongside coastal areas, hence affecting human life. When in large quantities, debris can hinder ships from navigating.
- Pollutants in the food chain- fish and other water creatures can consume pollutants, including chemicals, heavy metals, and garbage. Since humans consume these animals, the pollutants in them can quickly get to the food chain, finally accumulating in various seafood consumed by humans. Marine pollution contaminates shellfish and mussels that the seafood industry relies on.
- Source of ailments– marine pollution exposes humans who come into contact with contaminated water to several illnesses. For instance, a reproductive system failure can occur from prolonged exposure to toxic agricultural and industrial chemicals. Pollutants in ocean waters can expose humans to eye and skin irritation. Moreover, liver and lung problems can develop following exposure to oil by-products and oil spillages in the oceans.
- Disrupts the aquatic environment– the excess phosphorous and nitrogen resulting from widespread water pollution can lead to algal blooms. This disruption affects the ecosystem since algae overrun the ecosystem over time. Once alga blooms start to decompose and sink, the ocean waters’ oxygen levels can deplete drastically. This creates dead zones since marine life is unable to thrive in that hostile aquatic environment. Eventually, the disruption caused scares away fish and other marine species, prompting them to leave. Other fish species die if they are unable to flee.
How can we prevent marine pollution?
As detrimental as marine pollution is to the environment, this pollution can be prevented. Below are actionable ways of preventing marine pollution.
- Embracing biodegradable plastic options
Plastics have various adverse effects on the environment and are leading contributors to marine pollution. Plastic containers that we utilize on an everyday basis are non-recyclable. They end up in waterways, eventually getting into the oceans.
We should switch to biodegradable plastic options. Such options aren’t hazardous to the environment, and they decompose rather quickly. As such, the chances of biodegradable containers getting to the oceans are minimal.
- Managing ballast water effectively.
Ballast water helps with maintaining the ship’s stability and maneuverability as it navigates in oceans. This water hosts sea animals, and hence it has implications on the aquatic ecosystems once discharged.
The environmental pollution caused by ballast water can be dealt with effectively by the maritime authority. For instance, maritime companies can switch to huge containerships since they use a smaller volume of ballast water. Again, ships can use blast water that contains fewer creatures.
- Installing tight air seals in ships
Oil spillages are prevalent in the oceans. They kill many fish spices each year. To prevent such disastrous spillages that jeopardize the marine environment, ships should have tight air seals to prevent accidental spillages.
- Taking part in beach clean-ups
Trash is detrimental to the marine environment since it litters beaches and further contaminates ocean waters. Eliminating trash is an excellent precaution measure to counter marine pollution. Since rubbish will forever find its way to the marine environment, the public should be encouraged to take part in regular beach clean-ups.
- Reducing rubbish and recycling
We should reduce our quantities of rubbish. These actions significantly reduce the amount of waste that usually gets into the oceans. Recycling is an effective way of reducing litter. Papers, plastic containers, and cans can be recycled. Companies also need to lower their packaging to reduce rubbish in the long-run.
- Avoid draining sewage into the oceans.
Sewage leads to massive water pollution. It also packs infectious bacteria that cause diseases such as typhoid and cholera. Despite a booming construction industry, builders should be prohibited from draining sewage into oceans to save the marine environment.
Visible plastic waste makes up just 3% of total plastic in the ocean. Tackling the root causes of plastic pollution can also curb other ocean pollutants.
— World Resources Inst (@WorldResources) May 30, 2020
7 solutions here: https://t.co/2yTb83Mphz
Let us work at addressing the marine pollution problem
Marine pollution is rife. Worse still, this pollution is caused by multiple factors, all of which are challenging to keep at bay. Nonetheless, action ought to be taken to counter marine pollution, preventing it from compromising the marine life and human health.
Marine pollution is an urgent environmental issue. Trash and chemicals from land and ships pollute the vital aquatic ecosystems, with plastics being a major pollutant.
David Okul is an environmental management professional with over 10 years experience on donor projects, conservation, forestry, ecotourism, and community-based natural resources management. When not working on active environmental management projects, I spend my time writing for Silvica on a variety of topics.
