Marine Pollution - One Ocean (2023)


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The world’s marine pollution comes in many forms – from toxic chemicals, sewage and fertilisers to plastics, discarded fishing nets and even the noise from shipping and drilling. Over 80% of it originates from land-based activities (WWF, n.d.), whether due to accidental spills, deliberate dumping, untreated effluent, atmospheric fall-out, or the run-off from drains and rivers.

(Video) Marine pollution, 1st theme of the 2017 #OurOcean conference

Marine pollution is highlighted as a major challenge by the ground-breaking 2019 UN IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) assessment, which states that more than 80% of global wastewater is being discharged back into the environment without adequate treatment, while 300–400 million tonnes of heavy metals, solvents, toxic sludge and other industrial waste are dumped into the world’s waters every year (UN, 2016).

In the UN’s Sustainable Development Goal target 14.1, states pledge to: ‘’By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution.”(UN SDG, 2019)


Marine pollution is defined by the 1982UN Convention on the Law of the Seaas: “the introduction by man, directly or indirectly, of substances or energy into the marine environment … which results or is likely to result in such deleterious effects as harm to living resources and marine life.” (UNCLOS, 1982)

It can changethe physical, chemical, andbiological stateof the oceanandcoastal areas, posing a threat to marine wildlife and ecosystems, andthe industries and livelihoods dependent on them, such as fisheries andtourism. Toxic chemicals also become concentrated in the food chain and can impacthuman health.

There are three significant forms of oceanic and coastal pollution:

(Video) Ocean Decade Challenge 1: Understand and beat marine pollution

  • nitrogen-phosphorous pollution from agriculture, sewage, and urban and industrial run-off;
  • chemical pollution that comprises, but is not limited to, pesticides, petroleum, pharmaceuticals and personal care products, heavy metals and industrial discharge;
  • plastic-debris pollution.


Nitrogen and phosphorus pollution, alsocalled nutrient or eutrophic pollution, has a global impact on ocean bodies andis particularly concentrated in coastal areas near the estuaries of majorrivers.

Agriculture is a primary source of nitrogen and phosphorous, through the run-off of excess nutrients from animal manure and chemical fertilisers. On average, around 20% of nitrogen fertiliser is lost through surface run-off or leaching into groundwater and up to 60% can vaporise into the atmosphere, a portion of which will subsequently fall on the ocean (World Resources Institute, n.d.).

There has been a tenfold increase in global fertilizer use since the mid-20th century and nitrogen discharges from rivers into the sea rose by 43% between 1970 and 2000, with more than three times as much coming from agriculture as from sewage (Breitburg et al., 2018). However, there are regional variations. While agriculture is the leading source of nutrient pollution in the United States and the European Union, urban wastewater is often the primary source in South America, Asia and Africa (World Resources Institute, n.d.).

Non-agricultural sources of excess nitrogen and phosphorus include stormwater, wastewater, fossil fuel burning, aquaculture and domestic waste (EPA, n.d.). In the Baltic Sea, atmospheric depositions from burning fossil fuels accounts for 25% of nitrogen input. Similarly, in the Chesapeake Bay in the United States, atmospheric deposition accounts for 30% of all nitrogen input, while the smog from industry and vehicles in China blown over Yellow Sea is a significant source of nitrogen causing severe eutrophication (World Resources Institute, n.d.).

A serious impact of eutrophication is the algal blooms that can be toxic to marine ecosystems. When the dense algal blooms die off, their decomposition severely depletes the dissolved oxygen in the water, potentially causing “dead zones” where the oxygen levels are so low that fish and other organisms struggle to survive. This impacts fisheries and tourism. One of the world’s largest dead zones occurs every summer in the Gulf of Mexico as a result of nutrient pollution from human activities throughout the vast Mississippi River watershed.In 2017, it reached a record size of 8,776 square miles (NOAA, 2019).

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A host of chemical pollutants are having a harmful effect on ocean health. These chemicals come from a range of sources including crude oil and other petroleum products, antifoulants, pesticides, pharmaceuticals and personal care products. It is estimated that the total amount of chemicals entering the ocean rose by 12% between 2003 and 2012. Although the level coming from North America and Europe dropped by 60% during that period, in the Pacific it rose by 50% (UN, 2016).

Marine water quality and wildlife are seriously affected by oil from spills, discharge and shipping. Major oil spills capture headlines and are difficult to clean up but are in fact declining due to improved technologies and policies. In 1990, 1.1 million tonnes of oil were lost in spills. By 2015 this was down to around 25,000 tonnes, but this still represents over 10% of the oil entering the ocean (Anderson, 2013). The remainder enters the ocean via rivers, drains, coastal activities and shipping.

The most dangerous pollutants are the persistent, bioaccumulative, and toxic substances. Even chemicals banned decades ago, like polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), are still found in high concentrations in deep sea creatures despite being banned by the 2001 Stockholm Convention (Jamieson et al., 2017). Since they do not break down easily, these chemicals accumulate in marine organisms, becoming more concentrated further up the food chain. Animals like seals, polar bears and large fish can have contamination levels in their bodies millions of times higher than the surrounding water.

Pollutants recognised as endocrine disruptors and teratogens, which impact the ability of marine species to reproduce or reduce offspring survival rates, present a growing concern (IPSO, 2019). Personal care products in particular contain cryptic chemicals that have a significant impact on human and ocean health (Dinardo and Downs, 2018). For example, oxybenzone, a common ingredient in sunscreens, has been found to negatively impact coral health and reproduction (Downs et al., 2016).


Plastic pollution in the ocean has captured the attention of the global public in recent years, following the publication of alarming statistics and the circulation of distressing images showing the harm plastic is causing to ocean wildlife. Marine plastic pollution is flagged as a major threat by the 2019 IPBES Assessment, which warns that it has increased tenfold since 1980, affecting at least 267 species, including 86% of marine turtles, 44% of seabirds and 43% of marine mammals (IPBES, 2019).

(Video) the IMO’s Maritime Week Day 3 Seminar on “Marine Pollution”

An important 2015 study calculated that 275 million tonnes of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million tonnes entering the ocean (Jambeck et al., 2015). Taking an average of 8 million tonnes of plastic flowing into the ocean every year, that is equivalent to dumping the contents of one garbage truck every minute. If no action is taken, this is expected to increase to two per minute by 2030 and four per minute by 2050. Considering that the best research currently available estimates that there are over 150 million tonnes of plastics in the ocean today, a business-as-usual scenario would result in 1 tonne of plastic for every 3 tonnes of fish by 2025, and more plastics than fish (by weight) by 2050 (Ellen MacArthur Foundation, 2017).

It is estimated that between 1.15 and 2.41 million tonnes of plastic waste enters the ocean every year from rivers, with over 74% of this occurring between May and October. The top 20 polluting rivers, 15 located in Asia, account for 67% of this global total, while the top 122 polluting rivers contribute over 90% (Lebreton et al., 2017).

Other sources are coastal mismanagement, abandoned fishing gear and microplastic particles from household cleaners, personal care products and viscous clothing. Ocean currents are gathering much of the plastic within the five sub-tropical ocean gyres – including the infamous 1.6 million km2 Great Pacific Garbage Patch (Lebreton et al., 2018). This is causing some, even very remote places to be inundated with plastic. Henderson Island in the Pacific has been named the most polluted island on the planet when it comes to plastics, while plastics have been found at the depths of the Mariana Trench and embedded in ice in the Arctic.

Briefing prepared on behalf of the OneOcean initiative contact


How much ocean pollution is in the ocean? ›

There are 5.25 trillion pieces of plastic waste estimated to be in our oceans. 269,000 tons float, 4 billion microfibers per km² dwell below the surface. 70% of our debris sinks into the ocean's ecosystem, 15% floats, and 15% lands on our beaches. In terms of plastic, 8.3 million tons are discarded in the sea yearly.

What is the solution for plastic pollution? ›

1. Wean yourself off disposable plastics. Ninety percent of the plastic items in our daily lives are used once and then chucked: grocery bags, plastic wrap, disposable cutlery, straws, coffee-cup lids. Take note of how often you rely on these products and replace them with reusable versions.

How can we prevent ocean pollution essay? ›

One of the simplest ways to reduce ocean pollution is to properly dispose of plastics and other recyclable materials, so they don't end up in the ocean. In outdoor spaces, such as beaches and parks, dispose of trash in a secure receptacle or take it home with you.

Why is ocean pollution caused? ›

Ocean pollution is caused by the introduction of toxic materials and harmful pollutants such as agricultural and industrial waste, chemicals, oil spills, and plastic litter into the ocean waters.

Why is the ocean so polluted? ›

All marine debris comes from people with a majority of it originating on land and entering the ocean and Great Lakes through littering, poor waste management practices, storm water discharge, and extreme natural events such as tsunamis and hurricanes.

Why is ocean pollution a problem? ›

About 10 million metric tons of plastic waste enter the oceans each year, killing seabirds, fish, and marine mammals. It breaks down into smaller pieces called microplastics that absorb a range of chemicals floating in the marine environment, including pesticides and toxic metals.

Why do we need to clean the ocean? ›

The air we breathe: The ocean produces over half of the world's oxygen and absorbs 50 times more carbon dioxide than our atmosphere. Climate regulation: Covering 70 percent of the Earth's surface, the ocean transports heat from the equator to the poles, regulating our climate and weather patterns.

What are the effects of ocean pollution? ›

The increased concentration of chemicals, such as nitrogen and phosphorus, in the coastal ocean promotes the growth of algal blooms, which can be toxic to wildlife and harmful to humans. The negative effects on health and the environment caused by algal blooms hurt local fishing and tourism industries.

Who pollutes the ocean the most? ›

These 10 countries are the biggest contributors to marine plastic pollution – new analysis
  • China (21.5 billion kg)
  • Brazil (10.6 billion kg)
  • Indonesia (9.1 billion kg)
  • Russian Federation (8.4 billion kg)
  • Germany (6.6 billion kg)
  • United Kingdom (6.4 billion kg)
  • Mexico (5.9 billion kg)
  • Japan (4.8 billion kg)

How can we control plastic pollution essay? ›

We must take major steps to prevent it. We must use alternatives like cloth bags and paper bags instead of plastic bags. If we are purchasing plastic, we must reuse it. We must avoid drinking bottled water which contributes largely to plastic pollution.

Why is protecting marine life important? ›

Marine Protected Areas are important for the future because it can protect depleted, threatened, rare, and endangered species and populations. Furthermore, protecting MPA's can help preserve habitats that are considered critical for the survival of lifecycles of species.

Why should we stop ocean pollution? ›

A healthy ocean regulates climate and reduce climate change impacts. Ocean currents distribute heat across the globe, regulating temperature and weather. The ocean also absorbs over 90% of the heat and approximately 30% of carbon dioxide emissions produced by human activities.

Who does ocean pollution affect? ›

Ocean pollution affects whales, turtles, dolphins, sharks, fish, sea birds, and are frequently injured from debris and unable to survive. Marine life is quickly entangled in debris such as fishing nets and plastic. Fish that consume microplastics are then caught for human consumption.

When did marine pollution start? ›

Ocean pollution became increasingly apparent in the late 1960s, with researchers conducting some of the first intensive studies on plastic litter. Scientists noted occurrences of Laysan Albatrosses ingesting plastic items and northern fur seals becoming entangled in netting.

What is the biggest problem in the ocean? ›

Climate change arguably presents the greatest threat to ocean health. It is making oceans hotter, promoting acidification, and making it harder to breathe in them by reducing dissolved oxygen levels.

How will ocean pollution affect the future? ›

Physical impact on marine life: entanglement, ingestion, starvation. Chemical impact: the buildup of persistent organic pollutants like PCBs and DDT. Transport of invasive species and pollutants from polluted rivers to remote areas in the ocean. Economic impact: damage to fisheries, shipping, and tourism.

How can we save marine life from plastic? ›

Together, we can protect the ocean.
  1. Avoid buying single-use plastic whenever possible.
  2. Avoid individually wrapped items such as snack packs and single-serve containers. ...
  3. Fill a reusable bottle instead of buying bottled water. ...
  4. Use your reusable bag and containers when shopping, traveling, or packing lunches.

What is the main source of pollution? ›

The main sources of pollution are household activities, factories, agriculture and transport. Once they have been released into the environment, the concentration of some pollutants is reduced by dispersion, dilution, deposition or degradation.

How long would it take to clean the ocean? ›

How long will it take to clean up a gyre? A complete cleanup of a gyre is unrealistic, but our ambition remains to clean up 90% of ocean plastic by 2040.

What is the biggest pollutant? ›

The biggest polluter changes if we ask the question another way. Who has polluted the most since the industrial revolution? The United States tops the list of countries that have emitted the biggest amount of carbon dioxide in total since the industrial revolution.

How can we make a plastic free environment? ›

Food Consumption
  1. Carry reusable utensils and containers to work. ...
  2. Carry lunch and other meals in a reusable container. ...
  3. Carry sandwiches and snacks in reusable lunch wraps. ...
  4. Use your own reusable container for takeout and leftovers. ...
  5. Use reusable coffee cups and drink bottles. ...
  6. Cut out frozen meals. ...
  7. Use a reusable bread bag.

How plastic harm our environment? ›

Chlorinated plastic can release harmful chemicals into the surrounding soil, which can then seep into groundwater or other surrounding water sources, and also the ecosystem. This can cause a range of potentially harmful effects on the species that drink the water.

How is plastic harmful? ›

The harmful chemicals released from plastic products throughout their entire life cycle can pose a serious risk to humans and the environment, including when waste is not properly managed, finding its way to air, water and soils.

Can we live without plastic? ›

.. driving would no longer be safe because replacing the plastic parts with other materials makes driving a risk. Think of a windshield wiper made of wood, it would be warped in no time so that the rain on your window cannot be removed.

Who invented plastic? ›

Its inventor, the Birmingham-born artisan-cum-chemist Alexander Parkes, patented this new material in 1862 as Parkesine. Considered the first manufactured plastic, it was a cheap and colourful substitute for ivory or tortoiseshell.

Is gum made of plastic? ›

True Gum doesn't contain plastic or any chemicals. Instead it is made of a natural chicle gum base which comes from the sap of the Sapodilla tree. So True Gum is one way to keep on munching without chewing on plastic.

How much pollution is in the ocean 2021? ›

There is now 5.25 trillion macro and micro pieces of plastic in our ocean & 46,000 pieces in every square mile of ocean, weighing up to 269,000 tonnes. Every day around 8 million pieces of plastic makes their way into our oceans.

How much pollution goes into the ocean each year? ›

Every day approximately 8 million pieces of plastic pollution find their way into our oceans. 12 million tonnes of plastic are poured into the ocean every year.

How much plastic is in the ocean 2050? ›

Starting with an estimate that 150 million tonnes of plastic are already polluting the world's oceans, and that "leakage" adds at least 9.1 million tonnes more each year — a figure that is said to be growing by five per cent annually — the MacArthur report calculates there will be 850-950 million tonnes of ocean ...

What will happen to the ocean in 2050? ›

Experts say that by 2050 there may be more plastic than fish in the sea, or perhaps only plastic left. Others say 90% of our coral reefs may be dead, waves of mass marine extinction may be unleashed, and our seas may be left overheated, acidified and lacking oxygen. It is easy to forget that 2050 is not that far off.


(Doctor Griffiths)
2. How Do We Fight Marine Plastic Pollution? | One Small Step
(NowThis Earth)
3. One Ocean - Our Future exhibition
(Australian National Maritime Museum)
4. Ocean Pollution 1
5. Our Ocean Conference: Marine Pollution
(U.S. Department of State)
6. Marine Pollution Lecture (OCE-1001)
(Sven Holbik)
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