Targeting Rivers To Keep Plastic Pollution Out Of The Ocean

Since the widespread manufacture of plastics began in earnest in the early 1950s, plastic pollution in the environment has become a major global problem. Nowhere is this more evident than the Great Pacific Garbage Patch. A large ocean gyre that has become a swirling vortex full of slowly decaying plastic trash, it has become a primary target for ocean cleanup campaigns in recent years.

However, plastic just doesn’t magically appear in the middle of the ocean by magic. The vast majority of plastic in the ocean first passes through river systems around the globe. Thanks to new research, efforts are now beginning to turn to tackling the issue of plastic pollution before it gets out to the broader ocean, where it can be even harder to clean up.

Why Rivers?

The Great Pacific Garbage Patch is the most well-known area of ocean pollution, though four other similar gyres exist worldwide where ocean currents cause plastic pollution to gather. Image credit: The Ocean Cleanup

Recent studies have shown that river outflows are primarily responsible for the huge amounts of plastic entering the ocean each year. This is largely due to plastic being discarded on land, which then finds its way into waterways via storm drains and other routes. Rivers and stormwater systems serve to collect huge swathes of litter in this way, and then deliver them directly to the ocean.

In comparison, the direct dumping of garbage into the ocean pales in comparison to these sources. Estimates suggest that 1,000 rivers worldwide are collectively responsible for 80% of the plastic reaching the world’s oceans.

On top of this, there are efficiency gains to be had by carefully choosing the methods in which the problem is tackled. A recent study explored the impact of several different potential projects on plastic pollution levels. Existing ocean clean-up devices were shown to have an almost-negligible impact, whether deployed singularly or in numbers up to 200.

Graph showing the predicted effects of different mitigation strategies on plastic pollution. The greatest results are from a combination of river barriers and ocean collection devices. Image credit: ScienceDirect

Worse, such a deployment would have huge budgetary and labor requirements to run and maintain, for little real-world benefit. With long term modelling, the deployment of 200 ocean cleanup devices would result in roughly 816,000,000 kg of floating plastic remaining in the ocean by 2150.

However, the comparatively tractable solution of installing river barrier systems to collect plastics would have a much larger  impact. The team’s modelling showed that this would leave a much smaller amount of floating plastic in the ocean – just 398,000,000 kg – by the same milestone. Obviously, this does nothing about the plastic already in the ocean, but the research paper notes that a combined approach would net the greatest gains.


Putting Good Ideas Into Practice

Interceptor 002 in operation in the Klang river, Malaysia. The eventual goal of The Ocean Cleanup is to deploy similar systems in 1,000 rivers worldwide. Image credit: The Ocean Cleanup

With the numbers so decisively in favor of tackling the problem at the river level rather than out on the open seas, cleanup efforts have gotten down to work. The Ocean Cleanup have begun deploying their autonomous Interceptor craft to oceans around the world, and begun the long, ongoing task of reducing plastic outflows closer to the source. Built with a catamaran design, natural river currents guide waste plastic into the craft’s collection apparatus. There, the plastic is scraped from the surface of the water, and stored in dumpsters on board until ready for collection by local authorities. The entire craft is solar powered, and aims to collect waste with as minimal additional environmental impact as possible. Already, the team have delivered their fourth Interceptor, now undertaking operations in the Rio Ozama in the Dominican Republic.

The benefit of tackling plastic pollution at this level is that it no longer becomes a problem to be solved far from land, well beyond national borders, over thousands of miles of ocean. Instead, it’s a problem that can treated as something to be solved by local governments, where what are essentially point-sources of ocean pollution can be dealt with individually. In this way, it can almost be considered that the river is aiding in the collection of waste plastic such that it can be more effectively captured and disposed of properly.

No Silver Bullets

This river in Bandung, Indonesia, became clogged with plastic in 2018. Trucks were unavailable to haul the plastic away, so construction equipment was used to push the mass downstream. Much of this plastic likely entered the ocean. Image credit: David Shukman/BBC

Despite the positives of finding a better, more effective way to tackle ocean pollution, the problem is still far from solved. There are many more rivers that still need to stem the flow of garbage, and the plastic already in the ocean isn’t going anywhere.

We also need better techniques for dealing with the plastic that is captured.  Recycling efforts are ongoing in a multitude of ways, but fundamentally, mixed garbage that has been floating at sea generally doesn’t serve as a great feedstock for making raw quality materials for future use. While burning plastics may feel wrong, it’s not actually as bad as it sounds, and will serve as a better option than landfill in the medium-term until better solutions come along.

Ultimately, one of the best solutions to the problem is going all the way to the top, and stemming consumption in the first place. Initiatives to reduce the amount of single-use plastics in use are ongoing, and will have a significant role to play in solving the problem. Plastic that isn’t made can’t be thrown away, after all. Efforts in developing improved biodegradable plastics and less-wasteful packaging will continue to net gains, as well.

In the end, the solution to the plastic problem will require work in many diffuse areas. Only by reducing consumption and waste, stemming garbage outflows, and cleaning up what’s already out there, will we see a pristine ocean once again on Earth.

49 thoughts on “Targeting Rivers To Keep Plastic Pollution Out Of The Ocean

  1. “The vast majority of plastic in the ocean first passes through river systems around the globe.”

    And here I thought it was all the garbage barges dumping their loads directly into the ocean.

      1. This. One Chinese river carries more than half of all the plastic in the oceans. And my small town in the Pacific Northwest of the USA, where all garbage is land-filled or recycled, banned plastic grocery bags in order to save endangered sea turtles in the Indian Ocean. If I ask them how many sea turtles we have killed so far they say “We have to start somewhere!” Schools are important. This is how civilizations die.

        1. It’s compliance training and do-as-I-say-so-I-feel-better rolled into one.

          Not only that, if the plastic bags are of the quickly dissolving type, there are no sea turtles that will ever be killed by them. (And given that the US properly disposes of almost 100% of its garbage, even a traditional plastic bag would be unlikely to kill one of them turtles.)

          1. Whoosh! Great example though. Apples to door knobs. Now tell us how you are going to ban mercury lab barometers because they use mercury to recover gold on the Amazon river.

          2. “greenhouse emissions”, care to explain the thermodynamics of that hypothesis to me? I’m serious because I’ve never seen it done in a way that accounts for all relevant phenomena and in proportion to their actual occurrence in the real world. Just the raw maths and physics, no policy, opinion or politics, you know actual science. I have tried to find such evidence to support the belief that there is a linear relationship between CO2 production by humans and global temperature changes, but I can’t actually find any complete physical model that is plausible.

          3. “there is no point us decreasing our greenhouse emissions”

            In the developed West, greenhouse emissions will drop naturally due to drives toward efficiency of energy use. Unless the increase in emissions due to the rapid rise in standards of living in heavily populated countries like India and China with unenforced or loose environmental laws are addressed, the huge expense of ADDITIONAL mitigation in the West is not worthwhile, leading me back to the natural drop of emissions due to increasing efficiency. Also, lets go 100% nuclear using 4th generation reactors instead of the ANTIQUATED types used now that “burn” <1% of their nuclear fuel with the rest being highly radioactive waste to ones that burn 97% with some even able to burn the waste from the antiquated nuclear plants.

            And, BTW, here's a graph of mismanaged plastic waste by country:


  2. If this article from Scientific American is accurate, a few of these systems could put a noticeable dent in new plastic pollution. The Yangtze River alone is suspected of dumping 1.5 metric tons of plastic pollution into the Yellow Sea. See the chart of the Top 10 River Sources of Plastic Pollution.

    1. Oh yes and we don’t contribute to the problem at all by continuing to throw money at these unscrupulous folks to purchase their goods. No indeed we should just continue to consume as usual and expect everyone else to take the blame.

      1. Sure, if you are into blame transference away from the person who performed the act. Anti-litter campaigns and pollution rules did wonders in the USA in the 1960’s and it has steadily improved since (baring some cities that refuse to police the offenders). The CCP can do it anytime they want. Their economy and thus their hold on power is too fragile.

  3. I propose a slalom course of nets, slant down, slant up, \ , / \ } allowing fish to find their way around them, and wallets to be returned to their owners, and whatever is not returnable is classified as net profits.

    1. conveyor nets, ofc. looping, dumping into bins onshore, operating on hydro power ofc.. and more nets can be crafted from plastic bottle slicing, plastic bag stretching/weaving, thereby allowing for even more net profits! also: bottle caps or whatever moldable thermoplastics turn up can be converted into oars/ paddles, impellers, whatever, for sale or for parts for the hydromechanical side of things. As for any unlucky fish gathered in the process, i propose that the recovered plastics also be converted into tarps and other housing for hobos and hippies who can cook or release the fish at their discretion.

  4. Out of sight, out of mind. For many, they wouldn’t care, if it where in sight, if they had to do something extra to prevent that. Plastic, will be produced, until the price of petroleum rises to a price much higher than it is today. Many items made from plastic, where hand crafted items using biodwgradable, renewable resources. While we should pay for that labor, it’s not as we will be drepived of anything. I’m old enough to remember laundry baskets made from wide thin wood strips.

  5. Anyone remember the “Plastics make it possible” commercials?
    I swear there was a whole generation that grew up thinking glass containers would shatter if you look at them wrong, and never figured out how to load a paper grocery bag without ripping it. Laundry baskets, shelving, light covers, beverage containers my effing God, poorly breathing polyester clothes, Greenbriar International, food wrapped within wrappers within cardboard…. 🤮
    How about a “Glass is good” campaign? There are at least a couple breweries here that conduct bottle recovery programs instead of letting them go through the typical energy inefficient recycling process. Now I’m curious how well that works for them..

    1. Glass bottles are transparent to light which ruins beer. Aluminium cans make for better beer and they are very easy to recycle, unlike glass which must be picked over carefully to remove all the Grolsh beer caps which will ruin an entire recycling batch.

      1. Recycle, Reuse, Reduce was the ad I heard in the 90s.

        Swing tops are often Reused. In the case of micro breweries they are highly reused.

        I have never seen a clear swing top bottle. Also Grolsch is in green swing tops, which reduces UV passage.

        Reduce, less plastic is created if a plastic item highly reusable, as a swing top is. E.G. I have a few flip top jars for pickles from the 70s with glass lids, I just change the gaskets every decade.

        1. Sure they are “mostly” reused but it only takes one to ruin an entire batch of recycled glass. Thanks for proving my point. Remember that the entire can is readily recyclable with no slave labor needed to remove the tops.

      2. Brown bottles, ya know. The thing about glass is that it’s made from sand, which isn’t very polluting and becomes sand again after a trip down the river. Please do let me know if there’s something more to the breakdown of glass that I’m not aware of.
        Also, I’m sure you know that aluminum cans are still lined with plastic. Aluminum corrodes fast enough, but the plastic is again my grumble. I would complain extra about the 6er rings, but it seems the hard plastic tops have become prevalent enough.
        I’ve been brewing for years, and I go to great lengths to make sure it touches as little plastic as possible. It only takes using a strong flavored ingredient once before you realize that plastic holds and releases chemicals far more than you’d like.

        1. So what are your bottle caps lined with? I’m guessing there is a lot more plastic in a beer bottle cap than there is lining a beer can. And you’ve never bought a 12 pack of cans in a cardboard box? Your home canning escapades are irrelevant to the mass manufacturing issues that must be addressed by the consumer market. And you just ignore the issues of sorting colored glass, maybe you can find some slaves to do it?

          1. The bottle redemption center seems to be able to pay an American minimum wage for people that sort around 50 containers in maybe a minute.
            A batch of home brew nets around 2.5 cases, that is 60, 12oz bottles. The bottles get filled over and over, meaning after a few dozen batches, I’ve offset literally 2160+ bottles from having to be shipped, sorted, cleaned, broken down, melted and purified, formed into a new bottle, shipped to the brewery/ bottler, cleaned again, and shipped again, just to get more ethanol to my intake manifold.
            I rarely buy 12 packs. If I’m going for volumes, home brew comes 2.5 cases per batch. I don’t often want to taste the same beer 12 times in a row, unless it’s mine.
            I’m not convinced that the lining of a bottle cap actually contains more plastic by weight than the lining of a can. Wanna do a test and report back? I’m thirsty and I got fresh $ from cashing in recyclables just now..
            I thought of you and timed my trip 😊 50 containers in 47 seconds chucking them in the auto sorting machine as fast as I could grab and stick them in. The lady at customer service sorted through two sacks of non- redeemable items to fish out 13 containers in about the same time. At that rate, I guess my home brewing (the high pressure steam sterilization of food is generally what folks call canning) would have saved someone 2 3/4 hours of digging through trash or some 45 minutes of just feeding a sorting machine.
            I have lots of friends and business in the local beverage industry, so you’re going to have to elaborate on those mass manufacturing issues that makes refillable bottles not sensible. I’ll go hit up Double Mountain and see what they know, because they’ve been doing it a hot minute.

          2. So you forgot to mention all of the packaging for your ingredients, and the truck rides they took from factory to warehouse to warehouse to store to your house, when the brewery gets bulk ingredients shipped directly with minimal packaging.

            And you are arguing with some imaginary straw man when you talk about bottling at a brewery because I am talking about canned beer.

        2. Broken beer bottles will take hundreds and hundreds of years to become sand, in the meantime they are deadly hazards to people and wildlife. Beer cans with a deposit are worth money and the free market will clean them up as people like money. Broken beer bottles cannot be redeemed and so they will remain on the roadsides.

          1. Here in Germany, you pay 8 cents for a beer bottle and get them when you bring it back. But some people still crush them on streets and parks. C0ca-c0la and ice tea bottles ? many of those are not recyclable here.

        3. The real joke here is you think you are saving the planet by making your own beer but in fact your home brewed beer takes about 10:times more energy to make than beer from a mass market brewery.

  6. There is something you all is forgetting.
    70% of all the garbage actually come from the west and is shipped to asian countries.
    Ship after ship with millions of tons of garbage end in landfillls and rivers in china , cambodia , hilippines ect ect.
    I extremely happy to see that more and more Asian countries now say STOP.
    Here in the philippines Ship after Ship filled with garbage from Canada is sent back and Malaisia send several ships back to France fully loaded with plastic garbage.
    In Africa whole cities is built up around the trash from europe and Usa.
    Bangladesh is home to the most toxic salvage of western ships.
    Africa houses the most dirty salvage of electronic scrap together with china ,
    all imported from europe and annada and US.

    I lived in china several years before moved to philippines and in china they have
    spend years to build up recycling facilities in almost all cities.

    They have also a gigantic project running where the rivers is cleaned up.
    In the city where I lived is 5 rivers crossing and before I left 4 rivers was cleaned totally up.
    They are now so clean that fish life is back and people is allowed to fishing in the river because the fish is safe to eat.
    Most people doesn’t know what countries as china actually is doing to clean up and protect the envrionment.
    In just a few years china have plantet millions of trees and list can go on and on.
    In the city where I lived all Gasoline motor bikes is forbidden , only electric motorbikes is allowed and they did this 10 years ago Also more and more electric cars is now on the road , including that ALL taxis is electric and busses is as minimum hybrids.
    In china there is posters and signs every where in the cities ( yes in the west they say ” propaganda signs blah blah ”’ )
    If you took the time to actually learn the language then you will be able to read those.
    Those inform about envrionment and what you can do as a citizen to help protect the nature and envrionment and help
    combat the climate crisis.
    What your ‘ oh so informative Tv and medias and public postings ‘ NEVER tell you is what they actually is doing.
    It’s all about making asian countries the ” bad ones ”’
    Yes agree there was a time where it wasn’t good but that time is over…
    china is using more money and doing more for this than whole Europe and US together.

    The ONLY country there actually will be able to live up to the intyernational climate deal is China.
    ALL other countries talk and talk ( and the US denies ) but doing so little that it have almost NO effect at all.
    ( including my native country , they talk more than doing and as usual it end in political blah blah where
    in the end it’s more about taxes than really say ‘ OK now this is forbidden and this have to be changed ‘ )
    Yes my country invest in wind energy ect but … they are NOT doing much compared to the constant talking …

    China is leading in Using and develop wind , solar and Hydro power.
    Yes Hydro power and Dams to make electricity.
    Oh I forgot in the west they say ‘ china is so bad and regulate water to hurt it’s people blah blah ”’
    Yes again west speaking without a brain and those who actually understand the language can tell you that
    in ONE yes 1 year china shut down more than 50 coal powerplant .
    Thanks to the electricity from the Dams.

    Actually china have developed so effective solar pannels and so cheap that Europe have tried to an them
    when that failed they now put so high taxes on them that they are too expensive to use.
    They doing this to protect the industry that deliver power based on … yes the usual fuels …
    It’s all about money and secure the usual companies who it at the top of ”’ the power ”’

    Windmills is plenty in china and placed in all locations where they can generate electricity.

    Street lamps is powered by solar energy and every street lamp have its own solar pannel and a battery.
    From the lamps in the mountains to the lamps at the highways and in the cities.
    Some even have both solar pannels and a windmill in combination.
    This technology is also now arriving here in Philippines where more and more street lamps have solar pannels.
    Just two streets from where I live they are nearly finish installing them at 4 different roads and this is just the start.

    It’s very easy to just blame and say ‘ oh it’s china and philippines and blah blah there make the most pollution.
    Truth is that it’s actually the west but most is simply shipped away and ”” problem is gone ””

    Truth is that most people doesn’t know anything about those countries except from the usual western propaganda
    they feed you up with in Tv , radio medias , social medias ect ect.
    All carefully feed to keep the dark picture of the Asian countries ( especially china )
    It’s ”’ oh so important to keep have enemies ”’ back then it was USSR now it’s china …
    Shure they keep blame and talk bad so people they doesn’t look inside own countries and start see all the sh*t they
    actually is doing. ( including my native country ( not US ) )

    If the west could abandon all this hate against asian countries ( china ) then the west could learn many things.
    Share knowledge and build up a world based on clean energy and clean up all the trash.

    ( Oh I forgot……. ” those on the power benefits from the dirty industries ”’ Money and political hate against
    specific countries is the speciality of the west )

        1. So, you need a report on Geo-politics to read a scale? And China does not take US recycling and certainly not “garbage”. Some countries ship to SE Asia but they only take recyclables. Throwing it in rivers is throwing away money. Why such a desire to point fingers away from China?

  7. Regardless of which country the source is nearly always human fingers and selfish cares as these items are dropped and left to the world. I would be happy with every convenience and carry out food store having to have no external adverts only anti-littering “propaganda” including graphic pictures like the ones above and the same restrictions on all provided packaging that can be carried out of the store. Foam has to go. I remember when eggs came only in paper cartons.

    If we can ban decades ago the detachable pop-top in favor of one that remains locked to it’s can, we need to get rid of that tear-off strip top of cigarettes and individually tear-open wrapped food items.

    It’s time that the manufactured trash sources start paying for their customer mistakes. If every fountain filled cup had to have you submit ID that is coded onto the item and identification and prosecution possible things would change.

    1. It’s better to just charge the consumer up front for all the associated costs and let the market sort things out. People will change their habits in a hurry when they have to pay $5 or $10 for a plastic cup.

      1. What? I see we are headed to civil war. Ban the food. I need the cigarettes, booze, and gambling (no Gin from plastic bottle please). Research shows nicotine raises your IQ and concentration – a lot. It is how they went to the Moon and built the X-15 with slide rules.

  8. Here is an interesting fact that will shatter your world view, sampling of DNA found in water for different genes has shown the widespread existence of PET plastic digesting enzymes in aquatic microorganisms. This may be primordial as natural hydrocarbon leaks and deposits have been around for over 400 million years and or a more recent adaptation but what is clear is that life seems to be learning faster than humans when it comes to efficiently managing and utilising this form of carbon. (They are pretty good at digesting humans too. 😉)

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