10 river systems carry 99% of the plastic that ends up in the ocean

Question

More than 8 million tons of plastic ends up in the ocean each year. If we continue to pollute at this rate – there will be more plastic than fish by 2050. While some sources say that ocean plastics come from thousands of different origins, a study showed that there are 10 primary carriers. Eight of the ten are in Asia; the Yangtze, Indus, Yellow, Hai He, Ganges, Pearl, Amur, and Mekong, while the other 2 are in Africa; the Nile and Niger. It was reported that these rivers had more plastic per cubic meter than others. 

The study (https://www.ufz.de/index.php?en=36336&webc_pm=34/2017) also found that all these rivers had a few things in common; poor waste management, and high population density. While China is working actively to reduce plastic waste and find more effective ways of disposal, water pollution is still a large issue. 

Answer 1

The claim that 99% of plastic is carried into oceans through 10 rivers is mostly true. According to the World Economic Forum in 2018, rivers is Asia and Africa, "the Yangtze; Indus; Yellow; Hai He; Ganges; Pearl; Amur; Mekong; and two in Africa – the Nile and the Niger" carry between " 88 and 99% of the plastic that ends up in the ocean from rivers." The claim here is that, without a doubt, these 10 river systems carry 99% of the plastic to the ocean, but in reality, this percentage could be as low as 88%.

 To offer more context, I did some research onto what causes this exceedingly high level of plastic to be in just 10 river ways. According to a chart organized by Plos One, the common factor between these cities is an incredibly dense and high population and a poor waste management system. In order to decrease this high level of waste, these cities surrounding the rivers need to significantly increase recycling efforts. 

A second source supporting this claim, although the statistics are slightly lower is the Department of Hydrogeology through ACS publications in 2017 who found that the "10 top-ranked rivers transport 88–95% of the global load into the sea". According to this source, the percentage may even be lower than 99% and only as high as 25.

Overall, I believe that, for the most part, this claim is true, but it is also slightly misleading. It is true that these rivers carry a very high percentage of the world's plastic into the ocean, but it is not certain that it is exactly 99%. A more accurate claim that it more reflective of the available information would be that between 88 and 99 percent of plastic in the ocean originates from 10 specific rivers. 

 

Comments

I agree with your opinion that the claim is mostly true but slightly exaggerated. My favorite parts is when you do further research on the causes of this situation and concluded, based on other sources, that appropriately 88~99% of the plastic in the ocearn originates from 10 rivers.

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You did a really good job balancing accuracy and nuance here. I like that you didn’t just accept the 99% figure and instead compared it to other credible sources like the World Economic Forum and ACS. It shows careful research and critical thinking. One thing you could add, though, is a bit more about how population density and weak waste management directly contribute to the problem, like how inadequate trash collection near these rivers leads to runoff during rainy seasons. That small detail would help explain why these particular rivers carry so much plastic, making your fact check even stronger and more informative.

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I appreciate your ability to depict the claims exaggeration while crediting its truthfulness. I find your study of the graph in your research to be valuable in this example and you really went above and beyond doing this. Lastly, the way you tie all of your research together at the end to explain the truthfulness of the claim was important. Excellent job in your fact check and especially your research.

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This is a really nice fact check. You did a good job at explaining what you meant when you said the claim is mostly true. Explaining the statistics and how they can be interpreted both in the way the initial claim says but also in a different way that can still be seen as true was done in a very clear way.

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This is a very informative and well researched fact-check. I appreciate the usage of two sources which you compared before coming to a conclusion. If you could include the credibility of your sources it would have further supported your claims, but I still appreciate your careful analyzation of statistics and supporting research.

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Great job on tying in both the accuracy and the flaws of this claim! I really admire how you also included context to the claim, and deeply fact-checking the reliable sources you used. Explaining the statistics also helped me understand a lot better.

Answer 2

The source of this claim is a press release published by UFZ, a member of the Helmholtz Association, a German scientific organization. UFZ does environmental research for Helmholtz and is based out of Germany. Overall, this is a reliable looking organization based in research. The claim they make is “The researchers have also calculated that the ten river systems with the highest plastic loads (eight of them are in Asia and two in Africa) - areas in which hundreds of millions of people live, in some cases - are responsible for around 90 percent of the global riverine* input of plastic into the sea.”

From Nature, a leading international scientific journal:

“The top 20 polluting rivers were mostly located in Asia (Table 1) and accounted for more than two thirds (67%) of the global annual input while covering 2.2% of the continental surface area and representing 21% of the global population. Furthermore, the top 122 polluting rivers (4% of total landmass surface area and 36% of global population) contributed for >90% of the plastic inputs with 103 rivers located in Asia, eight in Africa, eight in South and Central America, and one in Europe.”

https://www.nature.com/articles/ncomms15611

It seems that 90% or more plastics in the ocean come from rivers, but not specifically from 10 specific rivers only.

From the Ocean Cleanup, a non-profit organization seeking to work to remove plastic from the oceans:

“Rivers are a major source of plastic waste in the oceans. We estimate that 1000 rivers, represented by the red dots, are accountable for nearly 80% of global annual riverine plastic emissions, which range between 0.8 – 2.7 million metric tons per year, with small urban rivers amongst the most polluting.“

https://theoceancleanup.com/sources/

There seems to be differing numbers of the exact number of rivers that the majority of ocean plastic comes from, but most research I came across seemed to agree it was more than 10 rivers. So while this claim is somewhat true, that >90% of ocean plastics come from rivers, it does not seem like it comes from 10 rivers precisely.

Answer 3

1. I found that rivers that run into the ocean are the largest contributors to pollution in the ocean. Urbanization leads to excessive pollution so the concentration of trash in waterways is higher. A large percentage of plastic emissions comes from pollution in rivers.

2. The Ocean Cleanup claims that 1000 major rivers around the world account for 80% global plastic emissions which translates to about 0.8-2.7 million metric tons every year.

https://theoceancleanup.com/sources/

Rapidly urbanized regions in Asia and Africa lead to the largest amounts of pollution, specifically large cities in China, Nigeria, and Indonesia. The Yangtze is the largest source of pollution.

https://www.weforum.org/stories/2019/02/visualizing-the-world-s-top-plastic-emitting-rivers-50fa978a87/

3. Plastic makes up two thirds of the trash found in rivers. Over the three-year period, local teams collectively removed and analyzed 3.8 million kilograms of river debris, the equivalent to 380,000,000 single-use plastic water bottles, with 66% classified as microplastic. The study is from UC Santa Barbara.

https://www.forbes.com/sites/jamiehailstone/2025/08/16/two-thirds-of-trash-found-in-global-rivers-is-plastic-study-finds/

Motagua is Guatemala’s longest river. By some estimates, the trash carried downstream by the Motagua River makes up roughly 2% of the total plastic waste that enters the world’s oceans each year.

https://www.cnn.com/world/4ocean-motagua-guatemala-pollution-c2e-spc

4. The potential bias in the CNN article is that they are a more left leaning new source, so they will be more realistic about the damage pollution is having on the rivers and oceans. The other potential bias would be in the Ocean Cleanup website because they track all trash being dumped into rivers/ oceans, whereas the original claim mentioned only plastic.

5. The evidence that the Yangtze is one of the 10 rivers contributing to the most pollution in the ocean is confirmed in the article from We Forum. This same source also confirms the claim that 8/10 rivers are in the Asia region and that urbanization is leading to more polluted areas.

6. The article about the Motagua River contribution to 2% of the ocean’s plastic pollution every year undermines the claim that the two continents with the larger pollution levels are Africa and Asia because the Motagua River is in South America.

Answer 4

This claim is misleading. It takes information from UFZ Centre for Environmental Research, which used claims from hydrogeologist Dr. Christian Schmidt and “Environmental Science & Technology” textbook. Although UFZ is considered a reputable source for environmental research and collaborates with international research facilities on high-quality problem solving, this article was published in October of 2017. A lot of this data could have changed since being recorded. 

In my further research I found a website created by The Ocean Cleanup company, discussing the source of plastic in rivers around the world. We estimate that 1000 rivers are accountable for nearly 80% of global annual riverine plastic emissions. This is completely opposite to the article used in this claim, which says only 10 rivers around the world contribute to the total plastic emissions in rivers, along with the percentage which is much less than the claimed 99%. The Ocean Cleanup has a whole website dedicated to the research of plastic in rivers, which makes the company appear to be pretty knowledgeable on this topic. 

Additionally, the Yangtze, Ganges, Yellow and Nile rivers were found on the 12 Most Polluted Rivers in the World list by Sea Smart posted on July 27th 2025. Some of the reasons for these highly polluted rivers include dumping of raw sewage, dumping from chemical factories, and algae blooms through eutrophication. These are all good reasons as to why the percentage of plastic emissions in these rivers may be higher than most.

Overall, the article used in this claim is valid and high quality, but it’s outdated. The articles and websites I found in my research are more up to date, and claim that the number of rivers contributing to the plastic emissions is much higher than 10, closer to 1000. Lastly,  the current articles say the percentage of plastic in rivers is much lower, around 80% or less.

Answer 5

This claim, "10 river systems carry 99% of the plastic that ends up in the ocean", came from the World Economic Forum, https://www.weforum.org/stories/2018/06/90-of-plastic-polluting-our-oceans-comes-from-just-10 rivers/#:~:text=According%20to%20a%20study%2C%2088%2D95%25%20of%20all,cubic%20meter%20of%20water%20than%20small%20rivers is a little exaggerated. The amount is not stated as an exact or definitive truth in the original source. Rather, according to the article, scientists calculated that "just 10 river systems carry between 88 and 99% of the plastic that ends up in the ocean from rivers." Additionally, the crucial phrase "from rivers" is omitted. The study did not examine all ocean plastic; it solely examined trash that enters the ocean through rivers. 

World Economic Forum is a valid source, even though the claim is exaggerated, because it's based on scientific research. The article cites a study by Dr. Christian Schmidt and colleagues at the Helmholtz Centre for Environmental Research, a respected scientific institution. https://www.ufz.de/index.php?en=36336&webc_pm=34/2017. Their research was peer-reviewed and published, meaning it went through a process to check for quality and accuracy. The article also explains how the researchers reached their conclusions by analyzing plastic waste in rivers and liking it to waste management and population density. It's a little biased. At the beginning of the text, emotionally charged language is used to draw readers in and arouse worry ("increasingly alarmed," "more plastic than fish by 2050"). While it is more critical of India ("not a single drop of the Ganga has been cleaned so far") , it highlights encouraging developments in China ("the speed and determination of the government to change is enormous").Due to the emphasis on Asian and African nations, the blame may inadvertently be shifted away from wealthier countries that export garbage and contribute to plastic pollution. 

Comments

I think this is an excellent response! You laid out each piece of evidence and stated its bias. In addition you explained each side of the argument and explained through sources and sited you evidence of how this may be labeled as exaggerated or misleading.

Answer 6

This statistic originally came from a 2017 study by Schmidt et al. in Environmental Science & Technology. That early research suggested that about ten large rivers (mostly in Asia and Africa) were responsible for the vast majority of plastic entering the ocean. The claim spread widely through National Geographic, The Guardian, and other media outlets, which is why it is still repeated today. However, later research found that this study used a limited dataset and left out most of the world’s rivers — especially smaller rivers in urban and coastal areas.

In 2021, a much more detailed peer-reviewed study by Meijer et al. in Science Advances used data from 1,656 rivers (instead of only 57). It found that over 1,000 rivers, not 10, account for around 80% of the plastic flowing into the ocean. This means plastic pollution is far more widely distributed and comes from many smaller and medium-sized rivers located near dense populations, not just a few mega-rivers.

So the claim is misleading not because it was fabricated, but because it is based on outdated science that has since been replaced by much better data. The “10 rivers” talking point oversimplifies the problem and can give a false impression that only a handful of countries are responsible, when in reality plastic leakage is a global issue spread across hundreds of waterways.

Meijer L.J.J., et al. “More than 1,000 rivers account for 80% of global riverine plastic emissions into the ocean.” Science Advances (2021).

Comments

Excellent fact check! I thought you laid out your research nicely and explained it well. Looks like a reputable source there, too.

Answer 7

After doing a research on this topic, i can confirm that this claim can be determined as misleading.  Although the claim is correct about how 8 of 10 rivers with the highest plastic pollution are in Asia. with  “the Yangtze River being the highest dropping an estimated 1.5 million metric tons of plastic waste into the Yellow Sea” it still does not lead to an estimate of 99% of plastic being carried into these rivers. But instead it ranges for about 80% -93% of global annual river plastic emissions. 

The primary source that I found was from “The Ocean Cleanup” a nonprofit organization that’s point is it continuously improve and minimize impacts of plastic found in the ocean and rivers. According to their article in which they displayed a map of major rivers sources that are responsible to plastic waste with most of them being in Asia. Stating that “nearly 80% of global annual riverine plastic emissions which range between 0.8 - 2.7 million metric tons per year”  just proving how although the statistic of plastic pollution being high is true its nowhere near the exaggerated claim of 99%. 

https://theoceancleanup.com/sources/ 

A second source I found was from “Scientific American” which is seen as a reliable source for current science news and developments, with a strong history of publishing articles by eminent scientist. Where they stated “the 10 rivers carry 93% of the plastic pollution with Yangtze alone estimated to dump 1.5 million metric tons”. Again displaying a number that is closer to the 99% but yet still not. 

https://www.scientificamerican.com/article/stemming-the-plastic-tide-10-rivers-contribute-most-of-the-plastic-in-the-oceans/

Overall, I believe the claim is misleading, but there is some truth to it. Plastic pollution has caused immense damage to our ecosystem, and we must find a solution soon before it’s too late.