Meeresverschmutzung

7. Is a global assessment of micro-plastics in the marine environment necessary?

The source document for this Digest states:

6. Panel discussion on the need for global assessment (session K)

6.1 Questions to the Panel

The Workshop concluded with a Panel Discussion (see Annex 2 for membership) on the need for a global assessment, and was asked to respond to 6 specific questions:

1. Is a global assessment of micro-plastics necessary?
2. What are the overriding reasons in support of any of these options to the UN stakeholders?
3. Is there sufficient information to do this now, bearing in mind that it could take up to three years to complete?
4. What needs to be done to fill the remaining gaps sufficiently (research & technology agenda, policy development needs, capacity building, etc)?
5. How do we link such activities to the UN-GA Regular Process and the Trans-boundary Waters Assessment Programme (TWAP)?
6. What sources of funding are available?

6.2 Conclusions of the Panel Discussion

6.2.1 Is a global assessment of micro-plastics necessary?

The workshop considered that a global assessment of micro-plastics could be beneficial at this time and recognised that there was both sufficient public concern and a need to provide further objective information on the topic to enable policy makers to act. The participants recognised that with limited resources available, politicians, administrations and the plastics industry would understandably give priority to redressing the overriding problem of marine litter and its socio-economic impacts. Furthermore, an assessment of the scientific status of micro-plastics alone would not be helpful. Instead, the workshop advised that a global assessment of micro-plastics should be firmly embedded in the wider scientific context of marine debris, making clear the key processes involved.

6.2.2 What are the overriding reasons in support of any of these options to the UN stakeholders?

A primary motivation for a global assessment is the growth in the production of plastics, slow-progress in introducing practices of management to treat solid waste around the world and the continued, if not increased, input of plastics to marine habitats. Once there, they cannot be recovered or removed in a cost-effective manner, or on a sufficiently large-scale to bring about a significant reduction. There is a tendency to see the fragmentation of plastics as ‘natural’ degradation – out of sight, out of mind - this is far from the truth as the plastics do not degrade on any meaningful timescale; they merely fragment and accumulate in sinks. Of even more concern is that they may behave differently as they become smaller (Browne et al., 2008), potentially impacting different organisms and environmental compartments. In order to be able to act in an appropriate and timely manner, it is essential for policy makers to be fully informed and an assessment could be used to assist on this issue, as well as to focus future research more efficiently.

It is still not clear from the Workshop discussions if micro-plastic indeed act as significant vector for transporting PBT’s, such as PCBs and PBDEs; the potential for transfer of toxic chemicals into organisms was seen as one of the key missing factors that needed to be addressed. There is, however, a concern that they might transport chemicals which would not otherwise reach the oceans by other routes such as by atmospheric transport; this needs urgent attention. Any assessment should take account of the extensive literature regarding relations between the concentration of the contaminant and it’s toxicological effect. In addition there is the, largely un-quantified, potential of physical harm from micro- plastic particles of different sizes entering the body, organs and cells of a wide variety of organisms (But see Browne et al., 2008). Representatives for the European Commission pointed out that marine debris (including micro-plastics) had been named as an indicator in the implementation phase of the EU Marine Strategy Framework Directive – marine debris is therefore very relevant for the member States and scientific support will be needed to develop the required Global Environmental Standards, so it is more a question of how soon such an assessment could be completed.

It was felt by the workshop that while there were some direct inputs of micro-plastics (pre- production pellets, facial scrubbers etc) overall, the generation of micro-plastics should be considered as a subsidiary part of the marine plastic litter problem; gaps in our understanding would be inevitable in such an assessment. The scale of the assessment and level of integration are important issues to consider. This assessment would therefore have to be more broad-based than the title of the current workshop implies. The broad consensus of the Workshop was of the need to reduce the sources of pollution, for which an improved knowledge of the sources was critical.

Marine plastic litter has an impact on socio-economics and health of humans, and public awareness has reached a level that demands action. Policy-makers will need to take an integrated view of the whole process and develop a range of options for policy, including packaging and treatment of/integrated wastemanagement from collection to final disposal. It was pointed out that society has been able to address two global issues successfully: the depletion of the ozone layer and acid rain. All of society and the industry is involved to some extent. More effective use and recycling of plastics and other materials could be seen as the next frontier.

6.2.3 Is there sufficient information to do this now, bearing in mind that it could take up to three years to complete?

A global thematic assessment usually sources its information from regional assessments and from other review documents summarizing the state of the art. Where specific review or regional data are missing, the assessment has to either accept that aspect as an unknown or can choose to carry out a survey of the scientific literature, to summarise the state of affairs, and insert this information in the overall assessment. Where an emerging issue such as micro-plastics is concerned, it is likely that a global assessment would have to summarize much of its input data directly from the scientific literature.

6.2.4 What needs to be done to fill the remaining gaps sufficiently (research and technology agenda, policy development needs, capacity building, etc)?

The EU representatives emphasised the need to identify and develop global environmental standards as well as to select a small number of broadly applicable indicators, with which to benchmark these standards. The workshop, in discussing such indicators, considered that the most obvious and easily measured would probably work best, e.g. the work on seabirds but also the trends in quantities of micro-plastics on beaches and in the water column Impacted areas should be compared with reference areas.

It is recognised that PBTs, by definition, have long lifetimes in the environment that should be taken into account in any assessment. The consensus was that there is insufficient evidence of chemical hazard to quantify the risk from PBTs associated with micro-plastics; for example, the bioavailability of contaminants from ingested plastics. The quantities of plastics entering the oceans are still largely unknown. Certain locations are known to be ‘hot-spots’ of microplastics accumulation but information is incomplete. Such knowledge is critical in order to get to grips with the marine plastic litter and micro-plastics problem. Modelling of surface currents might help to order to predict the occurrence of microplastic hotspots throughout the world. From the point of view of policy, it is considered that whatever interventions are recommended to reduce the problems of marine (plastic) debris, their effectiveness should be measurable using established methods (Underwood 1997). Others felt that the only sure solution was to prevent plastics from entering our waterways and reaching the sea.

6.2.5 How do we link such activities to the UN-GA Regular Process and the Transboundary Waters Assessment Programme (TWAP)?

Marine plastic debris and micro-plastics are both parts of the same trans-boundary issue. The first step in linking up to global assessment programmes was considered by the workshop to be the provision of a robust assessment of micro-plastics in the broader context of marine litter, recognizing that there is an urgent need for the recommendation of global indicators. GESAMP is in a position to provide such an assessment at the request of its UN sponsors, in particular UNESCO-IOC and UNEP. The workshop also recommended that standardisation of methods will assist the assessment process greatly, e.g. by adopting NOAA’s already developed sampling methods and strategies, which are partially based on the UNEP/IOC Guidelines (Cheshire et al., 2009) and other established international protocols.

6.2.6 What sources of funding are available – multi-stakeholder effort?

Given the convergent policy needs of the UN system and the European Union in developing global indicators of marine debris, including plastics and micro-plastics, the workshop participants were optimistic that funding for a global assessment could be found through a multi-stakeholder approach, including the plastics industry. It was suggested that links could be developed with the World Tourism Organization. The message from the workshop was clear that the interest of the stakeholders would be greater if micro-plastics was considered in the broader context of the marine litter problem and, in that respect, the relatively narrow focus of the current workshop on micro-plastics as a transport mechanism for PBTs would need to be expanded to look at the issues in an integrated manner.

Source & ©: ,  Proceedings of the GESAMP International Workshop
on micro- plastic particles as a vector in transporting persistent, bio- accumulating and toxic substances in the oceans. 28-30th June 2010, UNESCO-IOC,
Paris. 6. Panel discussion on the need for global assessment (session K), p.47-50.