TOPIC SHEET
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Marine litter1 103
GESAMP6 document of 1990 regarding pollution – not solid litter – and has been reproduced since extensively, becoming erroneously a widely accepted assumption.
Used plastics are not the only material entering the ocean and featuring in marine litter, but there is consensus that it is the most challenging material because it degrades slowly, is lightweight and can be transported over long distances, is abundant and has had documented impact on numerous marine organisms and habitats.
Global plastics production has grown consistently since 1950, reaching 299 million tonnes in 2013.7 The People’s Republic of China is the leading producer of plastics, manufacturing almost 25% of global plastics by weight. From the data in Figure 3.3 in Chapter 3, plastics account on average for 7 to 12% of MSW by weight, depending on the income level of the country.
While additional research in quantification of the financial losses incurred is necessary, a study indicates that the natural capital cost of the impact of plastics on marine ecosystems is at least 13 billion USD per year.8
For example, patches of marine litter exist floating in the oceans, accumulating in the five subtropical ocean gyres as shown in Figure 1. The Great Pacific Garbage Patch is one such collection of marine litter in the North Pacific Ocean. Marine litter is not limited to just this area, but
6 The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection, an advisory body to the UN system.
7 PlasticsEurope (n.d.) Plastics: The Facts 2014/2015 – An analysis of European plastics production, demand and waste data. See http://issuu.com/
plasticseuropeebook/docs/final_plastics_the_facts_2014_19122 8 UNEP (2014c).
is found in accumulation zones in other regions of the North Pacific.
A considerable amount of scientific effort over the last decade focused on attempting to document the multiple aspects of potential harm caused by used plastics to marine fauna and its habitat. Key issues relate to (i) entanglement: for example, sea turtles entangled in abandoned nylon fishing nets. One hundred and fifteen species (44 sea bird species, 9 cetacean species, 11 pinniped species, 31 invertebrate species/taxa, 6 sea turtle species) were reported entangled in marine debris in the US and a total of 200 species worldwide;10 and (ii) ingestion: for instance, seabird fulmars ingesting plastics, confusing it with food; and even zooplankton, bivalves, etc. may ‘feed’ on it. Ingestion of plastics could result in a series of problems, from physical harm to bioaccumulation of organic chemical compounds used as additives to the plastic polymers that are known to function as endocrine disruptors such as phthalates, bisphenol A (BPA) and polybrominated diphenyl ethers (PBDEs). Evidence has also accumulated on the absorption into the plastics within the sea of the hydrophobic chemical polluting compounds present in the water, including polychlorinated biphenyls (PCBs) and other persistent organics pollutants (POPs). Ingestion of
9 An updated figure showing the plastics accumulation in the Mediterranean Sea can be found at http://journals.plos.org/plosone/article?id=10.1371/journal.
pone.0121762 Cozar et al. (2015) Plastic Accumulation in the Mediterranean Sea. PLoS ONE 10(4): e0121762. doi:10.1371/ journal.pone.0121762 10 NOAA (2014).
Figure 1 Concentrations of plastic debris in surface waters of the global ocean9
Plastic concentration (g km-2) 00-50
50-200 200-500 500-1000 1000-2500
Source: Cózar et al. (2015) Plastic debris in the open ocean. PNAS Vol. 111(28), 10239-10244 http://www.pnas.org/content/111/28/10239.full.pdf
plastics with accumulated absorbed POPs may result in increased bioaccumulation in fish, in comparison to pure plastics, recent studies suggest. However, not all aspects are sufficiently understood. For instance, a recent study on ingestion of microplastics (<1mm) on small invertebrates (Marine Isopod Idotea emarginata) has shown that “microplastics, as administered in the experiments, do not clog the digestive organs of isopods and do not have adverse effects on their life history parameters.”11
The sequence of absorption, ingestion and potential bioaccumulation in marine living organisms may, through the food chain, pose risks for human health as well, but this scenario requires further exploration.
The list of potential damage of marine plastic litter to the natural and human-made systems also includes the migration of invasive species travelling attached to plastics; harm to reef corals and benthic communities at the seabed; formation of nano-/micro-colloids. Some of these hazards result in direct financial costs, from costly clean-up efforts for beaches of high aesthetical recreational value, to revenue losses from impeded tourism.
© Race for Water 2015 – Peter Charaf
There is considerable data on the size of plastics items found in marine environments, and micro-plastics prevail. However, there are no globally consistent quantification methodologies, and often data collected refer to numbers of items, with mass data needed for quantification of mass flows missing. Increased consideration is given to microplastics, defined as plastics under a certain particle size. These may stem from fragmentation of bigger plastic items (secondary microplastics) or may originate from additives in widely used cosmetics, such as facial exfoliators. Plastics are mainly fossil-derived, but there is increased production of bio-based polymers (bio-polymers). Whereas most
11 Hämer, J., L. Gutow, A. Köhler, R. Saborowski (2014). Fate of Microplastics in the Marine Isopod Idotea emarginata. Environ. Sci. Technol. 2014, 48, (22), p. 13451.
of the fossil and bio-polymers are non-biodegradable, both fossil and bio-polymers can be manufactured to biodegrade, but their degradability depends on the exact environmental conditions to which they are exposed.12 Great uncertainty relates to the decomposition and fragmentation of plastics. Sinking mechanisms and rates are also underexplored. Due to microorganisms and algae accumulating on the plastics debris over time (‘biofouling’),13 plastics may sink instead of float.
Hence, on a generic level, considerable evidence has been accumulated on the potential harm caused by plastics present in marine litter. There is consensus that this evidence suffices to lead to immediate action. Given the complex nature of the challenge, any solutions have to equally derive from a systems and multi-stakeholder approach, involving: (i) multiple materials (types of polymers and additives), products (from fishing nets, to plastic carrier bags, to sanitary products such as nappies, to hard thermosets in durable goods such as toys), and points of initial entry and transport into the marine environment (sea, rivers, sewerage systems, wind-blown, seashores – global flows in huge oceanic gyros); (ii) the various scales of impacts, from aesthetical and amenity loss to wildlife species health damage and entire ecosystem disruption; and (iii) the multiple human activities involved in causing the problem, from the innovation of chemical compounds, to product design, to modes of retail, consumption and lifestyles, such as littering of fast food packaging, to unsound solid waste disposal methods, such as in uncontrolled dumpsites.
Marine litter is one of many reasons why the elimination of open dumping in non-landlocked low- and middle- income countries needs to be a political priority.14 Despite the systemic complexity, the most critical intervention has to come from the waste and resources management sector. In most of the cases, except for accidents and natural disasters such as tsunami, it is sound waste management and resource recovery practices that can prevent used plastics from entering the sea. The most important actions are to identify the sources and transport routes of used plastics into the sea, for the plastics properties (chemical composition, fragmentation/degradation modes, absorption of POPs) and quantities with the potential to cause maximum harm. In particular, it is essential for the waste and resources academics and practitioners to work in close collaboration with all other stakeholders and come up with reliable estimates on the key sources and pathways and how to effectively circumvent them. With this information available, existing intervention action plans can be prioritized according to their effectiveness and new more effective ones can be devised if necessary.
12 Shah, A. A., F. Hasan, A. Hameed and S. Ahmed (2008). “Biological degradation of plastics: A comprehensive review.” Biotechnology Advances 26(3): 246-265.
13 DG-ENV European Commission (2011)
14 See Section 1.1 on the challenge of sustainable waste management and Topic Sheet 2, the 50 Biggest Dumpsites.
Marine litter1 105
Over the mid- to long-term, the proliferation of sound waste management collection and disposal practices, extended producer responsibility (EPR) that involves manufacturers and retailers, and behaviour change focused on littering individuals are possibly key aspects of any solution, but the details are still missing. At an intermediate stage, innovation will be needed around the litter generation points: upstream, that is, in the production chain, where redesign can potentially be important in reducing generation quantities and in mitigating the inherent risk posed by used plastics in marine environments; and downstream, where there can be innovation in the solid waste and resource management systems regarding collection. Long-term technical solutions for removal and value recovery from the existing used plastics in the world’s seas, shores and seabeds are still missing, and some of these places are marine areas beyond national jurisdiction, which could complicate decisions and actions.
There are many important initiatives, from local to worldwide, attempting to contribute in addressing the marine litter challenge. The problem is too big for any one organization or country to deal with alone and requires extensive collaboration. The Global Partnership on Marine Litter (GPML),15 hosted by the UNEP Global Programme of Action (GPA), was launched in June 2012 at Rio+20.
The GPML is a voluntary open-ended partnership
15 http://www.unep.org/gpa/gpml/gpml.asp
© NOAA
for international agencies, governments, businesses, academia, local authorities, nongovernmental organizations and individuals. It provides a platform for increased collaboration and coordination among these groups, promoting a collaborative dialogue to achieve its main goal: to protect human health and the global environment through the reduction and management of marine litter. The resolution on marine plastic debris and microplastics adopted by the United Nations Environment Assembly of the United Nations Environment Programme at its first session on June 201416 is also an important step in global collaboration.
Regionally and locally, the Marine Litter Action Network (MLAN)17 in the UK is an example of a relevant multi- stakeholder initiative, organized by the Marine Conservation Society. The National Marine Debris Monitoring Program (NMDMP) in the U.S. is a five- year program developed by the Ocean Conservancy with support from USEPA to standardize marine debris data collection and assess marine debris sources and trends in the U.S. Ongoing initiatives in Australia include the Coral Triangle Initiative, the Coordinating Body on the Seas of East Asia (COBSEA), and Asia Pacific Economic Cooperation (APEC) has had a working group addressing this issue since 1990. In the EU, the European Environment Agency (EEA) has developed Marine LitterWatch (MLW) for citizen engagement through organized citizen groups, a mobile application and a database.18
Targeted interventions through risk-based clean-up initiatives may be useful. The Global Underwater Awareness Association (GUWAA) has conducted clean-up exercises with its S.P.E.E.D. (Special Protection Ecology Environment Diving) Unit that consists of a diving team that aims at cleaning the seabed, rivers, and lakes worldwide.19 But while clean-up activities are good tools for raising awareness, they are not a long-term solution and are a very costly end-of-pipe approach.
16 http://www.unep.org/unea/UNEA_Resolutions.asp
17 https://www.mcsuk.org/what_we_do/Clean+seas+and+beaches/Campaigns +and+policy/Marine+Litter+Action+Network
18 European Environment Agency (2015). European citizens to help tackle marine litter.
http://www.eea.europa.eu/themes/coast_sea/marine-litterwatch/at-a-glance/
european-citizens-to-help-tackle
19 See Global Underwater Awareness Association (2013). http://whiteflagint.com/
guwaa/index.php/guwaa-projects/finished/guwaa-2nd-world-cleanup-2013