June 2019 (12:7)

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“[Ocean plastic] isn’t a problem where we don’t know what the solution is. We know how to pick up garbage. Anyone can do it. We know how to dispose of it. We know how to recycle.”

--- Ted Siegler, DSM Environmental Services, on building the institutions and systems needed to deal with plastic before it reaches the ocean

Editor’s note: Marine plastic has a profound impact on marine ecosystems – entangling and killing wildlife, spreading disease and non-native species, and even impairing the oceans’ creation of oxygen. Managing marine ecosystems will need to include managing the marine plastic problem. Last month the Skimmer reported on the impacts of marine plastic on the Blue Economy, including on tourism, fishing, and ecosystem services. This month, in the second half of our plastics coverage, we examine which policies to reduce marine plastic seem to work best.

There is an abundance of information out there on how to reduce one’s personal plastic consumption, with the ultimate goal of reducing the amount of plastic that is polluting marine (and terrestrial) ecosystems. There are also numerous great reports (examples here and here) on government and industry interventions for reducing marine plastic pollution. But what do we know about the efficacy and level of impact of these activities? Are we lumping actions which are likely to have relatively little impact on the problem with actions that potentially have huge impacts? Of course, the ideal is to eliminate all plastic pollution marine and terrestrial – but in this article, we attempt to:

  1. Provide perspective (by way of lots of numbers) for what actions are most likely to make the biggest difference in marine plastic pollution
  2. Provide information on what has been shown to work to reduce marine plastic pollution.

These proved to be quite difficult tasks due to how dispersed relevant information is and a dearth of research on the efficacy of marine plastic pollution reduction activities. What you read in this issue of Skimmer is a work in progress, and we welcome your feedback and additional input to improve it.

So how much plastic are we talking about?

Thanks for that, but that didn’t really say anything about what is effective at reducing marine plastic pollution…

  • Right. Broadly speaking there are four ways to reduce marine plastic pollution.
  1. We can reduce the amount of plastic produced (and consumed) with the expectation that if there is less plastic in circulation, less plastic would wind up in the ocean.[3]
  2. We can increase the reuse and recycling of plastic with the expectation that this would lead to less plastic waste, therefore less plastic would wind up in the ocean. This idea is related to the first since increasing reuse/recycling of plastic could decrease demand for plastic products made from virgin materials. We made it its own thing though because this doesn’t necessarily mean a decrease in plastic in circulation.
  3. We can reduce the mismanagement of plastic waste so that it doesn’t end up in the ocean.
  4. We can remove plastic from the ocean (or at least from the coast).
  • The figure below gives an idea of the range of actions that can be taken to reduce marine plastic pollution. Realistically, plastic is so ubiquitous in our lives that society needs to work on many – if not all – of these fronts (using locally appropriate approaches) to fully eliminate marine plastic pollution.

So, what seems most likely to have the biggest impact on marine plastic pollution?

What else should we be thinking about for reducing marine plastic pollution?

But you mentioned that prevention is generally superior. Other than improving waste management, what works for preventing marine plastic pollution in the first place?

  • Almost certainly, preventing most marine plastic pollution would be less expensive than removing the plastic from the ocean, particularly once it is in the open ocean or has degraded into smaller fragments. Moreover, cleanup of most plastic in the ocean is not even technologically or economically feasible with current methods because  more than 95% of marine plastic pollution is below the surface.
  • Prevention efforts largely focus on packaging and other single-use items because they comprise a large percentage of plastic waste and are the most egregious example of the mismatch between its time in use and how long it remains in the environment.
  • In terms of prevention actions, we found two methods with demonstrated efficacy at reducing marine plastic pollution – the implementation of plastic bag bans and fees and deposit-return schemes.  These are discussed in detail in the next two sections.

Let’s talk plastic bag fees and bans – they work but one should proceed carefully

  • Plastic bags are at the forefront of the world’s efforts to reduce plastic usage. Consequently, the body of research on (1) the effectiveness of plastic bag fees/bans at reducing plastic usage and marine plastic pollution and (2) the environmental impacts of switching to other alternatives is much more developed for plastic bags than it is for other plastic products.
  • To put it mildly, the world uses a lot of plastic bags – somewhere between 1 and 5 trillion a year. And a lot of them end up in the ocean. In 2012, 23% of drifting marine litter and 59% of the marine litter found on beaches in China was plastic bags.
  • Measures to reduce the number of plastic bags (and amount of plastic) that reach the ocean include:
    • Banning them
    • Charging a fee for using them (usually between $0.05-$0.30 a bag),
    • Taxing manufacturers for making them,
    • Otherwise restricting the manufacture, distribution, use, and trade of them (e.g., banning imports or exports of them), and/or
    • Regulating their disposal (in the form of collection and recycling, take back, and/or deposit-refund requirements or fines for improper disposal).

As of July 2018, 127 countries had taken at least one of these measures at a national scale. And numerous cities and regions around the world have also taken action on this front even if their national government has not.

Deposit-refund programs also work – often really well

  • Deposit-refund programs (also known as container deposit legislation - CDL) also work. In deposit-refund programs, a small fee is added to the purchase price of something (most frequently beverage bottles) when it is purchased, and that deposit is returned to a consumer [or collector] when the container is returned. In general, the higher the deposit, the higher the return rate.
  • Over 40 countries worldwide have some form of these CDL programs for plastic bottles. They  are very effective at recovering materials[6] Norway’s deposit-return program for plastic bottles captures 97% of the country’s bottles for recycling – and new research shows that they can reduce coastal and marine plastic pollution. A comparison of litter in US and Australian states with and without CDL found 40% fewer containers in beach litter in states with CDL than states without CDL. This effect was even greater in poorer areas where mismanaged waste is a bigger problem.
  • Unfortunately, deposit-refund programs are often opposed by industry, and the bottling industry, including Coca-Cola, is working to resist a national container deposit program in Australia.

Fixing one of the fundamental mismatches of marine plastic pollution with Extended Producer Responsibility

In last month’s issue of The Skimmer, we described two fundamental mismatches that are at the heart of marine plastic pollution:

  1. That we are using an incredibly durable material for a lot of very short-term uses
  2. That the price of making and using things made out of plastic does not reflect the full cost of disposing of that plastic.

One of the most important mechanisms to address this second mismatch is Extended Producer Responsibility (EPR). EPR makes plastic producers or the businesses that sell the plastics responsible (financially and/or logistically) for products after consumers are done with them. This shifts the cost of managing post-use plastics from local governments to industry and business, in line with the ‘polluter pays’ principle, and it encourages the development of products that are more easily reusable and/or recyclable. Sixty-three (63) countries have some form of extended producer responsibility for single-use plastics, including deposit-refund programs (described above), product takebacks, and recycling targets.

In an interview with World Finance magazine in July 2018, Judith Schäli, a researcher at the World Trade Institute, gave this perspective about the importance of targeting measures to reduce marine plastic pollution at industry and businesses:

“Corporations that are involved in the market of plastic products, especially consumer products, play an important role in the shaping of our production and consumption patterns. They influence consumer behavior [through] commercials and subliminal advertisement in packaging. By their material choices and product designs, they determine the durability of their products, as well as their recyclability, biodegradability, ecotoxicity and susceptibility to end up in the environment. They further influence consumers’ product choices by providing or withholding information about the materials they use, including the additives with potentially toxic or otherwise hazardous effects.

In order to reduce their impact, companies should be aware of, and take responsibility for, the whole life cycle of their products, including disposal… They can redefine their business models and overcome the phenomenon of planned and perceived obsolescence, which pushes consumers to constantly renew their belongings by artificially limiting the service life of the products or suggesting that they are outdated.”

Finally, why reducing plastic consumption is an upstream swim

Want to discuss marine plastic pollution?

If you want to follow and discuss the latest on marine debris in real time online, join MarineDebris.info, the global online community for sharing knowledge on research, management, and prevention of ocean litter.

[1] Plastic waste leakage is the “amount of unmanaged plastic waste entering the ocean”.

[2] ‘Primary microplastics’ are plastic pieces that enter the ocean in this size range, while ‘secondary microplastic’s are ones that form in the ocean as a result of the degradation of larger plastic pieces.

[3] Although this article would seem to vilify all plastic, that is not the case. Plastic is a rather amazing (and amazingly versatile) product. It can be manufactured in a mindboggling variety of ways to form everything from Saran wrap to Kevlar. It is lightweight, waterproof, stable over a fairly wide range of temperatures, and relatively easy and “inexpensive” to create (especially if you’re not responsible for cleanup…) It is used to do a lot of things we appreciate –reduce food waste, prevent the spread of diseases, insulate homes, help us transport things, etc. Very few groups are proposing that we get rid of all plastics. But we would like to keep them and related toxins out of our oceans, our groundwater, our air, our food, our bodies, etc.

[4] Waste-to-energy conversion (including incineration, gasification, and pyrolysis) is highly controversial in many locations because it produces toxic emissions (both gases and solids) and would likely compete with recycling processes. Modern incinerators are capable of meeting more stringent emissions standards than previous generations of incinerators, however, and there is likely a place for them among a portfolio of measures to reduce the negative effects of plastic pollution.

[5] Editor’s note: As an urban dweller who walks to the market and has experience with a wider variety of bags, my take from reading all of these reports is that using (and reusing) recycled PET or polyester bags and disposing of them properly at the end of their useful life is currently the most environmentally friendly option for grocery hauling.

[6] It is worth mentioning that the advent of reverse vending machines – currently found in grocery stores and other locations in Iceland, Norway, Australia, Canada, and some US states – is making deposit-refund programs even easier to implement.


1:  Plastic waste produced and mismanaged. Maphoto/Riccardo Pravettoni for GRID Arendale, 2018. http://www.grida.no/resources/6931

2:  A family who moved from the Guizho Province to the rich Yangtze River Coast in search of new opportunities, working in a landfill sifting for any valuable resellable items. Sheila, 2007. https://www.flickr.com/photos/[email protected]/408525044 

3:  Reducing Plastic Pollution: Possible Actions. Allison Brown produced for OCTO and The Skimmer, 2019. https://meam.openchannels.org/news/oc-overview/reducing-plastic-pollution-possible-actions

4:  Waste picker in General Santos, Philippines. Global Environment Facility, 2013. https://www.flickr.com/photos/thegef/8652549158

5:  Mr Trash Wheel. Matthew Bellemare, 2016. https://commons.wikimedia.org/wiki/File:Mr._Trash_Wheel_(27582099121).jpg

6:  Are most of the plastics produced still around? Maphoto/Riccardo Pravettoni for GRID Arendale, 2018. http://www.grida.no/resources/6914

7:  Pollution on beach. Hhach. https://pixabay.com/photos/garbage-environment-beach-pollution-2369821/

8:  Reverse vending machine for the NSW Container Deposit Scheme located in the Woolworths Wagga North (Gurwood St) car park. Bidgee, 2017. https://commons.wikimedia.org/wiki/File:Reverse_vending_machine_for_the_NSW_Container_Deposit_Scheme_located_in_the_Woolworths_Wagga_North_car_park_03.jpg


Editor’s Note: For this article, we interviewed Ekaterina Popova, a global ocean modeller with the National Oceanography Centre in Southampton, United Kingdom, about her new article "Ecological connectivity between the areas beyond national jurisdiction and coastal waters: Safeguarding interests of coastal communities in developing countries" published in Marine Policy in June 2019. This research found that coastal regions of some least-developed countries (LDCs) are connected to areas beyond national jurisdiction (ABNJ) through larval dispersal and the potential dispersal of pollutants. These findings suggest that protecting ‘source’ areas in the ABNJ could help promote sustainable livelihoods for coastal regions that depend on larval supply from these regions (and could prevent pollutants from these source areas reaching coastal regions.) 

The Skimmer: Can you briefly describe some of the connections between source areas in the ABNJ and coastal regions?

Popova: Our study showed that connectivity between the ABNJ and coastal waters of different countries varies considerably. How tight the connectivity is, depends on the prevailing direction, timescale and variability of ocean currents. Sometimes, the shape of the adjacent Exclusive Economic Zones (EEZs) also has an effect. The complex ways these various factors interact means that close geographical proximity, or ‘adjacency’, of coastal waters to ABNJ is not always a good indicator of strong connectivity and some countries are much more exposed to the influence of ABNJ than others. The world’s most ABNJ-impacted LDC is the Federal Republic of Somalia. Its strong connectivity is shaped by three powerful currents: the South Equatorial current, the East African coastal current, and the seasonally reversing East Somali current. The most tightly ABNJ-connected stretch of the Somali coastline can be impacted by the upstream ABNJ waters on a time scale of just over a month. In contrast, the Republic of Senegal is one of the world’s least connected LDCs. Its most tightly ABNJ-connected coastline stretch is impacted by upstream ABNJ on a time scale of more than seven months.

At the same time, not all areas in the ABNJ are equally important in their influence on the coastlines. Some areas of the ABNJ are connected to more countries and impact longer stretches of the coasts than others. In this respect, the Mascarene plateau in the central Indian Ocean, the northern Bay of Bengal, and the “donut hole” of the Pacific Islands are the most prominent areas. In general, the Indian Ocean with its energetic and seasonally reversible circulation is the most connected of the all ocean basins. Given that it is surrounded by numerous developing countries, where coastal populations are highly dependent on the ocean ecosystems for food and livelihoods, we need to think very carefully how to regulate activities in its ABNJ.

The Skimmer: In your recent paper in Marine Policy, you focus on LDCs. Can you tell us anything about ecological connectivity between the ABNJ and coastal regions globally? Are there any broad characterizations that can be made about what types of areas are source regions and/or coastal regions that are highly connected to ABNJ?

Popova: The ocean is a very interconnected system, and ocean currents are complex and highly variable in time and space. It is possible, however, to draw some general patterns of the global connectivity. Naturally, it is strongest where there is a strong surface current directed towards a coastline. Westward flowing equatorial currents are probably the most pronounced example of this and provide a strong connection between ABNJ and the countries on the east coasts of continents. This is why our study highlighted East Africa as one of the most ABNJ-exposed areas, and this is also why west coasts of continents are generally less connected to the ABNJ in the tropics.

The Skimmer: Is ecological connectivity between coastal regions and ABNJ being discussed at all in current UN negotiations on the conservation and sustainable use of marine biodiversity of the ABNJ?

Popova: Connectivity in general and the connectivity between ABNJ and coastal zones in particular are indeed beginning to draw a lot of attention at the UN Convention on the Law of the Sea (UNCLOS) negotiations. It was explicitly mentioned in the ‘President’s Aid to Negotiations’ document for the March 2019 negotiations in relation to both Marine Protected Areas (MPAs) and Environmental Impact Assessment (EIA) elements of the negotiations. In addition, during the negotiations in March 2019, a number of side events dedicated to connectivity were run at the UN. One of these events (“So far, yet so close: why the High Seas matter to vulnerable coastal communities?” ) was based on the results of our study and a study on future scenarios and projections for fisheries on the high seas under a changing climate. The key questions discussed at this event were:

  1. What is ecological connectivity, and to what extent is marine biodiversity in ABNJ connected to territorial waters?
  2. Why does conservation of the high seas need to take into account socioeconomic impacts on coastal developing states?
  3. What are future scenarios and projections for fisheries in the high seas under a changing climate?
  4. How will climate change impacts on biodiversity in the high seas affect potential revenue from fish in coastal developing states.

This event had a full house attendance, and we received very positive feedback, particularly from Pacific small island developing states. The event would not have been possible without co-hosts, the permanent missions of Malawi (chair of the LDCs Group), Eritrea, and Sweden.

Our study has exposed a number of important considerations. However, the key message we are delivering in this complex process is a simple one – the current debates on criteria to identify marine managed and marine protected areas in the ABNJ often focus only on the ecological and biological significance of the habitat/area in question. Given interconnectedness of the ocean environment, this is not enough. We have to include potential socioeconomic benefits for vulnerable coastal communities downstream of these areas.

Photo: Fish Market in Zanzibar, Tanzania, Credit: E. Popova, NOC.

Editor’s Note: From the Archives calls attention to past Skimmer/MEAM articles whose perspectives and insight remain relevant.

To some in conservation and resource management, marketing can seem like a bad word. But marketing is inherently about getting people to change their behavior, whether it is buying a product, recycling, or supporting a new approach to management. Marketing techniques bring together elements of psychology, sociology, economics, and graphic design. Learn from three experts how to use conservation marketing to make marine conservation and management processes more effective.