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LITTER AND MICROPLASTICS MONITORING GUIDELINES ARCTIC MONITORING & ASSESSMENT PROGRAMME version 1.0 AMAP

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The purpose of the guidelines is to review existing knowledge and provide guidance for designing an Arctic monitoring program that will track litter and MP. The topics of litter, plastic pollution, and MP are addressed in many fora, including several of the Arctic Council working groups: Arctic Monitoring and Assessment Programme (AMAP; https://www.amap.no/documents/doc/amap-assessment-2016-chemicals-of-emerging-arctic-concern/1624), Protection of the Marine Environment (PAME, 2019), and Conservation of the Arctic Flora and Fauna (CAFF). The development of an Arctic monitoring program and its technical approaches will be based on the work that already exists in other programs such as those of OSPAR, the Helsinki Commission (HELCOM), the International Council for the Exploration of the Sea (ICES), the Organisation for Economic Co-operation and Development (OECD), and the United Nations Environment Programme (UNEP). Plastic pollution is typically categorized into items and particles of macro-, micro-, and nano-sizes. These guidelines address macrosized litter as well as MP (< 5 mm), essentially including smaller size ranges (>1 µm). However, determination of nanoplastic (< 1 µm) particles is still hampered by technical challenges, as addressed in Section 4.3 Analytical methods, and thus not currently considered in the current recommendations. Although most studies have addressed marine litter and MP, these guidelines also comprise the Arctic’s terrestrial and freshwater environments. Thus, the objectives of the guidelines are to: 1) support litter and MP baseline mapping in the Arctic across a wide range of environmental compartments to allow spatial and temporal comparisons in the coming years; 2) initiate monitoring to generate data to assess temporal and spatial trends; 3) recommend that Arctic countries develop and implement monitoring nationally via community-based programs and other mechanisms, in the context of a pan-Arctic program; 4) provide data that can be used with the Marine Litter Regional Action Plan (ML-RAP) to assess the effectiveness of mitigation strategies; 5) act as a catalyst for future work in the Arctic related to biological effects of plastics, including determining environmentally relevant concentrations and informing cumulative effects assessments; 6) identify areas in which research and development are needed from an Arctic perspective; and 7) provide recommendations for monitoring programs whose data will feed into future global assessments to track litter and MP in the environment. To achieve these objectives, the guidelines present indicators (with limitations) of litter and MP pollution to be applied throughout the Arctic, and thus, form the basis for circumpolar comparability of approaches and data. In addition, the guidelines present technical details for sampling, sample treatment, and plastic determination, with harmonized and potentially standardized approaches. Furthermore, recommendations are given on sampling locations and sampling frequency based on best available science to provide a sound basis for spatial and temporal trend monitoring. As new data are gathered, and appropriate power analyses can be undertaken, a review of the sampling sizes, locations, and frequencies should be initiated. Plastic pollution is a local problem in Arctic communities, and thus, guidelines and references need to include community-based monitoring projects to empower communities to establish plastics monitoring with comparable results across the Arctic. Community-based monitoring is an integrated part of the objectives of this report. The monitoring program design and guidelines for its implementation are the necessary first steps for monitoring and assessment of litter and MP in the Arctic. The work under the AMAP LMEG is taking a phased approach under this new expert group. The first phase (which included the development of these Monitoring Guidelines) focuses on a monitoring framework and set of techniques for physical plastics. Later phases of the work will extend to assessments of levels, trends, and effects of litter and MP in the Arctic environment. The guidelines strictly cover environmental monitoring of litter and MP. This does not include drinking water or indoor air quality tests. Additionally, although there is an emphasis on examining litter and MP in biota that are consumed by humans, and thus of interest to human-health questions, the guidelines do not consider MP ingestion by humans.
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AMAP
LITTER AND
MICROPLASTICS
MONITORING GUIDELINES
ARCTIC MONITORING & ASSESSMENT PROGRAMME
version 1.0
AMAP
Arctic Monitoring and Assessment Programme (AMAP)
Educational use: This report (in part or in its entirely) and other AMAP products available
from www.amap.no can be used freely as teaching materials and for other educational
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In case of questions regarding educational use, please contact the AMAP Secretariat
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need to be obtained from original copyright holders.
Disclaimer: The views expressed in this peer-reviewed report are the responsibility of the
authors of the report and do not necessarily reflect the views of the Arctic Council, its
members, or its observers.
AMAP
LITTER AND
MICROPLASTICS
MONITORING GUIDELINES
Version 1.0
AMAP
Arctic Monitoring and Assessment Programme (AMAP)
Tromsø, 2021
AMAP Litter and Microplastics Monitoring Guidelines
AMAP Litter and Microplastics Monitoring Guidelines
__________________________________________________________________________________
© Arctic Monitoring and Assessment Programme, 2021
Citation
AMAP, 2021. AMAP Litter and Microplastics Monitoring Guidelines. Version 1.0. Arctic Monitoring
and Assessment Programme (AMAP), Tromsø, Norway, 257pp.
Technical production management
Jan René Larsen (AMAP Secretariat)
Technical and linguistic editing
Carolyn Mallory
Cover photograph
Jakob Strand
Back cover photograph
Peter Murphy
AMAP Litter and Microplastics Monitoring Guidelines
Table of Contents
Preface ............................................................................................................................. 1
1.0 Introduction ................................................................................................................ 4
1.1 Purpose of the guidelines .................................................................................................... 5
1.2 Existing frameworks with relevance for litter and microplastics monitoring ......................... 6
1.3 Importance of harmonization and standardization in litter and microplastics work .............. 7
1.4 Examining litter and microplastics across the Arctic ............................................................. 9
2.0 Guidance for Monitoring Abiotic Environmental Compartments ................................ 15
2.1 Wet and dry atmospheric deposition ................................................................................. 15
2.1.1 Introduction and description of purpose/aims of monitoring ............................................................ 15
2.1.2 Summary of available information/existing monitoring frameworks ................................................. 16
2.1.3 Trends in literature in Arctic regions .................................................................................................. 17
2.1.4 Benefits and limitations ...................................................................................................................... 18
2.1.5 Sampling strategy and methodology .................................................................................................. 19
2.1.6 Quality assurance/quality control (QA/QC) and reporting/data management .................................. 21
2.1.7 Existing monitoring for populations/contaminants in the Arctic ........................................................ 22
2.1.8 Suggestion for future activities/knowledge gaps ............................................................................... 22
2.2 Water ............................................................................................................................... 30
2.2.1 Introduction ........................................................................................................................................ 30
2.2.2 Status of global science ....................................................................................................................... 30
2.2.3 Trends to date ..................................................................................................................................... 33
2.2.4 Benefits of using water samples ......................................................................................................... 33
2.2.5 Methods .............................................................................................................................................. 34
2.2.6 Quality assessment/quality control (QA/QC) specific to the compartment/matrix ........................... 36
2.2.7 Existing monitoring for populations/contaminants in the Arctic ........................................................ 36
2.2.8 Recommendations .............................................................................................................................. 37
2.2.9 Knowledge gaps and research priorities ............................................................................................. 40
2.3 Monitoring of microlitter in aquatic and shoreline sediments ............................................ 46
2.3.1 Introduction ........................................................................................................................................ 46
2.3.2. Status of global science ...................................................................................................................... 46
2.3.3 Current levels in the Arctic .................................................................................................................. 47
2.3.4 Benefits of using sediments as a plastic monitoring matrix ............................................................... 48
2.3.5 Limitations to using sediments as a plastic monitoring matrix ........................................................... 48
2.3.6 Methods .............................................................................................................................................. 49
2.3.7 Quality assurance/quality control (QA/QC) specific to the compartment/matrix .............................. 52
2.3.8 Existing monitoring for sediments/contaminants in the Arctic .......................................................... 53
2.3.9 Recommendations .............................................................................................................................. 53
2.3.10 Research gaps ................................................................................................................................... 54
2.4 Terrestrial soils ................................................................................................................. 63
2.4.1 Introduction ........................................................................................................................................ 63
2.4.2 Existing monitoring frameworks for microplastics in terrestrial soils ................................................. 64
2.4.3 Sampling .............................................................................................................................................. 64
2.4.4 Quality assurance/quality control (QA/QC) for microplastics in terrestrial soils ................................ 65
2.4.5 Recommendations for monitoring microplastics in soils .................................................................... 65
2.4.6 Conclusions ......................................................................................................................................... 66
2.5 Ice and snow (from lakes and rivers, glacier cores, sea ice) ................................................. 69
2.5.1 Introduction ........................................................................................................................................ 69
2.5.2 Status of global science ....................................................................................................................... 69
2.5.3 Trends to date ..................................................................................................................................... 70
AMAP Litter and Microplastics Monitoring Guidelines
2.5.4 Benefits ............................................................................................................................................... 71
2.5.5 Limitations .......................................................................................................................................... 71
2.5.6 Methods .............................................................................................................................................. 72
2.5.7 Plastic identification ............................................................................................................................ 73
2.5.8 Existing monitoring for populations/contaminants in the Arctic ........................................................ 73
2.5.9 Suggestions for future activities/knowledge gaps .............................................................................. 74
2.6 Litter on Arctic and sub-Arctic shorelines ........................................................................... 79
2.6.1 Introduction ........................................................................................................................................ 79
2.6.2 Status of global science ....................................................................................................................... 79
2.6.3 Trends to date ..................................................................................................................................... 80
2.6.4 Pros and cons of monitoring ............................................................................................................... 80
2.6.5 Methods .............................................................................................................................................. 81
2.6.6 Quality assurance/quality control (QA/QC) ........................................................................................ 92
2.6.7. Existing monitoring for marine litter on Arctic shorelines ................................................................. 93
2.7 Seabed ........................................................................................................................... 100
2.7.1 Introduction ...................................................................................................................................... 100
2.7.2 Status of global science ..................................................................................................................... 100
2.7.3 Seabed mapping in the Arctic ........................................................................................................... 101
2.7.4 Trends to date ................................................................................................................................... 102
2.7.5 Benefits of monitoring ...................................................................................................................... 103
2.7.6 Limitations ........................................................................................................................................ 103
2.7.7 Methods ............................................................................................................................................ 103
2.7.8 Litter estimates based on imagery .................................................................................................... 104
2.7.9 Fishing for litter - abandoned, lost, or otherwise discarded fishing gear (ALDFG) ........................... 104
2.7.10 Quality assurance/quality control (QA/QC) .................................................................................... 105
2.7.11 Existing monitoring for contaminants in the Arctic ........................................................................ 105
2.7.12 Recommendations .......................................................................................................................... 106
3.0 Guidance for Monitoring Biotic Environmental Compartments ................................ 116
3.1 Invertebrates (benthic and pelagic) ................................................................................. 116
3.1.1 Introduction ...................................................................................................................................... 116
3.1.2 Summary of information to date ...................................................................................................... 117
3.1.3 Sampling ............................................................................................................................................ 119
3.1.4. Extraction ......................................................................................................................................... 119
3.1.5 Quality assurance and quality control .............................................................................................. 120
3.1.6 Recommendations ............................................................................................................................ 120
3.1.7 Existing monitoring for invertebrates/contaminants in the Arctic ................................................... 122
3.2 Fish ................................................................................................................................ 130
3.2.1 Introduction to microplastics in Arctic fish ....................................................................................... 130
3.2.2 Status of global science on microplastics in fish ............................................................................... 130
3.2.3. Rationale for monitoring microplastics in Arctic fish ....................................................................... 135
3.2.4 Methods ............................................................................................................................................ 140
3.2.5. Quality assurance/quality control (QA/QC) ..................................................................................... 143
3.2.6 Existing population or contaminants (not microplastics) monitoring in the Arctic .......................... 144
3.3 Seabirds ......................................................................................................................... 153
3.3.1 Introduction ...................................................................................................................................... 153
3.3.2 Trends to date, globally and in the Arctic ......................................................................................... 154
3.3.3 Benefits of using seabirds as indicators ............................................................................................ 154
3.3.4 Limitations of using seabirds as indicators ....................................................................................... 155
3.3.5 Methods to assess litter and microplastics in seabirds .................................................................... 155
3.3.6 Quality assessment/quality control (QA/QC) specific to the compartment/matrix ......................... 156
3.3.7 Existing monitoring for populations/contaminants in the Arctic ...................................................... 156
3.3.8 Recommendations ............................................................................................................................ 157
AMAP Litter and Microplastics Monitoring Guidelines
3.4 Mammals ....................................................................................................................... 173
3.4.1 Introduction ...................................................................................................................................... 173
3.4.2 State of the global science ................................................................................................................ 173
3.4.3 Information from the Arctic, and trends to date .............................................................................. 174
3.4.6. Methods ........................................................................................................................................... 176
3.4.7 Quality assurance/quality control (QA/QC) specific to the compartment/matrix ............................ 178
3.4.8 Existing monitoring of mammals in the Arctic .................................................................................. 178
3.4.9 Recommendations ............................................................................................................................ 179
3.4.10 Research gaps ................................................................................................................................. 180
4.0 Guidance for Analyses, Modeling, and Data Reporting ............................................ 187
4.1 Types of litter and microplastics monitoring programs in the Arctic ................................. 187
4.1.1 Introduction ...................................................................................................................................... 187
4.1.2 Types of monitoring programs .......................................................................................................... 187
4.1.3 Characteristics of robust monitoring programs ................................................................................ 190
4.2 Data treatment ............................................................................................................... 194
4.2.1 General recommendations on data reporting .................................................................................. 194
4.2.2 Data reporting to NILU/EBAS ............................................................................................................ 194
4.2.3 Data reporting to ICES/DOME ........................................................................................................... 195
4.3 Analytical techniques for the identification of microplastics............................................. 203
4.3.1 Background ....................................................................................................................................... 203
4.3.2 Optical identification methods ......................................................................................................... 203
4.3.3 Chemical analysis techniques ........................................................................................................... 206
4.3.4 Outlook: promising methods for small plastic particle (< 10 µm) quantification ............................. 214
4.3.5 Guidelines for the identification of microplastics ............................................................................. 214
4.4 Modeling ........................................................................................................................ 235
4.4.1 Introduction ...................................................................................................................................... 235
4.4.2 Efforts to date ................................................................................................................................... 236
4.4.3 Difficulties or challenges ................................................................................................................... 236
4.4.4 Data needed and data gaps .............................................................................................................. 237
4.4.5 Long-term benefits ........................................................................................................................... 239
4.5 Synergies with other research and monitoring programs ................................................. 244
4.5.1 Including litter and microplastics monitoring in ongoing contaminant monitoring programs ......... 244
4.5.2 Including litter and microplastics monitoring in other types of programs ....................................... 245
4.5.3 Ongoing monitoring programs .......................................................................................................... 246
5.0 Future Work for AMAP ............................................................................................ 251
Acronyms and Abbreviations ........................................................................................ 253
Authors and Affiliations ................................................................................................ 256
Version history ............................................................................................................. 258
AMAP Litter and Microplastics Monitoring Guidelines
1
Preface
Concerns about microplastics and litter in the environment have been raised at both global and
regional (Arctic Council, EU, OSPAR, Nordic Council) levels. The Working Group on Marine litter
plastics and microplastics and its POPs and EDC
1
components: challenges and measures to tackle
the issue (Gallo et al., 2017) discussed the potential impacts of marine plastics on marine biodiversity
and human health (November 2016).
The Nordic Council of Ministers declaration (2017) on reducing the environmental impacts of
plastics states that the Nordic countries aspire to be driving forces in efforts to promote a sustainable
approach to the production, use, waste management, and recycling of plastics, and the council has
decided to launch a program to follow up on this issue.
The Fairbanks Declaration from the Arctic Council (2017) notes “(…) growing concerns relating to
the increasing levels of microplastics in the Arctic and potential effects on ecosystems and human
health.”
The Arctic Monitoring and Assessment Programme (AMAP) is mandated to:
monitor and assess the status of the Arctic region with respect to pollution and climate change
issues.
document levels and trends, pathways and processes, and effects on ecosystems and humans, and
propose actions to reduce associated threats for consideration by governments.
produce sound science-based, policy-relevant assessments and public outreach products to inform
policy and decision-making processes
2
.
AMAP (2017) reported on environmental concentrations and trends of marine plastics and
microplastics and about the biological and toxicological effects of microplastics (MP) in the Arctic.
The Arctic Council Working Group, Protection of the Arctic Marine Environment (PAME),
conducted a desktop study on marine litter in the Arctic region (PAME, 2019). The report
recommended developing a Regional Action Plan on Marine Litter in the Arctic (ML-RAP), and this
plan was approved by the Arctic Council in 2021.
Despite the significant increase in available data on MP pollution and litter debris globally, including
in the Arctic, status reports lack standardization in methodology and reporting consistency. For
macroplastics, methodology exists in some regions (e.g., OSPAR). For MP, there are at present no
harmonized measurements, monitoring methods, or environmental indicators. How the extreme
environmental conditions of the Arctic might affect plastic transport and degradation processes is not
yet known. Emerging knowledge from lower latitudes may not be transferable to the Arctic
environment, so studies specific to Arctic conditions are needed.
The AMAP Litter and Microplastics Expert Group (LMEG) was established in the spring of 2019
with the mandate to:
1
endocrine disrupting chemicals
2
https://www.amap.no/about
AMAP Litter and Microplastics Monitoring Guidelines
2
1. Develop a monitoring plan and program for the monitoring of MP and litter in the Arctic
environment. The program design should secure the necessary information that can quantify and
document levels, trends, and impact/effects of MP and litter in the Arctic environment.
2. Develop necessary technical guidelines supporting the monitoring plan and program. The
guidelines should include:
Harmonized sampling of the biotic and abiotic matrices in the Arctic environment;
Guidance on matrix and site selection;
Standardized sample processing and analytical methods;
Quality assurance/quality control (QA/QC) procedures;
Guidance on data management and data reporting;
To the extent possible, a proposed set of standardized methods that would lead to an
assessment process.
3. Formulate recommendations on these topics and identify areas in which new research and
development are necessary from an Arctic perspective.
These technical guidelinesthe AMAP Litter and Microplastics Monitoring Guidelinessupport the
AMAP Litter and Microplastics Monitoring Plan (AMAP, 2021) and the Regional Action Plan on
Marine Litter in the Arctic (PAME, 2021). The guidelines have been prepared by LMEG and its
experts from Canada, Denmark, Faroe Islands, France, Germany, Iceland, Italy, Norway, Sweden, and
the USA, and have been subjected to an independent, external review prior to publication.
This is version 1.0 of the document. It is expected that the document will be updated, and future
versions will be under version control.
The views expressed in this document are the responsibility of the authors of the report and do not
necessarily reflect the views of the AMAP Working Group, the Arctic Council, its members, or its
Observers.
References
Arctic Council, 2017. Arctic Councils Fairbanks ministerial declaration. Arctic Council Secretariat,
Tromsø, Norway. 16pp. [online] URL: https://oaarchive.arctic-
council.org/bitstream/handle/11374/1910/EDOCS-4339-v1-
ACMMUS10_FAIRBANKS_2017_Fairbanks_Declaration_Brochure_Version_w_Layout.PDF?seque
nce=8&isAllowed=y
Arctic Monitoring and Assessment Programme (AMAP), 2017. AMAP Assessment 2016: Chemicals
of Emerging Arctic Concern. Arctic Monitoring and Assessment Programme, Oslo, Norway. 352pp.
[online] URL: https://www.amap.no/documents/doc/amap-assessment-2016-chemicals-of-emerging-
arctic-concern/1624
Arctic Monitoring and Assessment Programme (AMAP), 2021. AMAP Litter and Microplastics
Monitoring Plan. Arctic Monitoring and Assessment Programme (AMAP), Tromsø, Norway. 23 pp.
[online] URL: https://www.amap.no/documents/download/6713/inline
Gallo, F., C. Fossi, R. Weber, D. Santillo, M. Scheringer, J. Sousa, I. Ingram, A. Nadal, C. Perez, S.
Averous, F. Wang, F. Griffin, L. Devia, D. Lapešová and D. Romano, 2017. Working Group on
AMAP Litter and Microplastics Monitoring Guidelines
3
Marine litter plastics and microplastics and its POPs and EDC components: challenges and measures
to tackle the issue. Information Document of the working group of the Stockholm and Basel
Conventions Regional Activity Centers, April 2017. 16pp. [online] URL:
https://www.greenpeace.to/greenpeace/wp-content/uploads/2017/04/InfoDocument-WG-Plastics_BS-
Regional-Centres.pdf
Nordic Council of Ministers, 2017. Nordic Programme to Reduce the Environmental Impact of
Plastic. Nordic Council of Ministers, Copenhagen, Denmark. 24pp. [online] URL:
https://norden.diva-portal.org/smash/get/diva2:1092150/FULLTEXT01.pdf
Protection of the Arctic Marine Environment (PAME), 2019. Desktop Study on Marine Litter
Including Microplastics in the Arctic. PAME International Secretariat, Akureyri, Iceland. 118pp.
[online] URL: https://oaarchive.arctic-council.org/handle/11374/2389
Protection of the Arctic Marine Environment (PAME), 2021. Regional Action Plan on Marine Litter
in the Arctic. PAME International Secretariat, Akureyri, Iceland. 21pp. [online] URL:
https://oaarchive.arctic-council.org/handle/11374/2649
Beach litter survey in Nuuk, Greenland.
Photo: Jakob Strand
AMAP Litter and Microplastics Monitoring Guidelines
4
1.0 Introduction
Plastic pollution in the environment is of increasing ecological concern worldwide (UNEP, 2014). As
early as the 1970s, plastic litter in the marine environment was reported as a problem (Carpenter et al.,
1972). Today, plastic pollution is observed across all oceans as well as in terrestrial and freshwater
environments, even in remote regions such as the Arctic. Plastic pollution can enter the Arctic
environment through local sources such as communities, landfills, shipping, tourism, and fisheries
(PAME, 2019), but also from southern areas via transport by ocean currents, wind, sea ice, or biota
(Cózar et al., 2014a; Obbard et al., 2014). Consequently, plastic pollution has been found across the
Arctic environment, including on beaches (Bergmann et al., 2017; PAME, 2019), in snow (Bergmann et
al., 2019), in surface, subsurface, and seafloor water samples (Bergmann and Klages, 2012; Cózar et al.,
2014b; Huntington et al., 2020), and in sea ice (Obbard et al., 2014; Peeken et al., 2018). Recently,
microplastics (MP) have been reported in amphipods (Gammarus setosus; Iannilli et al., 2019), snow
crabs (Chionoecetes opilio; Sundet, 2014), and fish (Morgana et al., 2018), whereas the detection of
plastics in Arctic seabirds dates back to the 1960s (Provencher et al., 2017; PAME, 2019; Baak et al.,
2020).
Plastic pollution can have deleterious impacts on biota in a variety of ways, depending on consumer
species and the shape, size, and type of plastic (de Sá et al., 2018), but most documented impacts are from
entanglement and ingestion. Marine mammals, seabirds, turtles, and fish can become entangled in fishing
gear, rope, and plastic bags (Laist, 1987; Gregory, 2009; Provencher et al., 2017). If not directly causing
mortality, entanglement by and ingestion of plastic pollution may affect the fitness of individual
organisms by compromising their ability to capture and digest food, reproduce, migrate, and/or escape
from predators (Galloway et al., 2017; Rochman et al., 2019). As plastics break down in the environment,
they become available to a broader range of organisms. Ingestion of MP has, in some cases, resulted in
physical damage such as obstruction or internal abrasions (Wright and Kelly, 2017). In addition to
physical effects, marine plastics can transfer chemicals to the marine environment, concentrate them from
seawater, or act as vectors for alien species, such as bryozoans, barnacles, polychaete worms, hydroids,
and molluscs (Barnes et al., 2009; Hermabessiere et al., 2017). Despite the significant increase in
available data on MP pollution and litter debris globally, including in the Arctic, status reports lack
standardization in methodology and reporting consistency. For macroplastics, methodology exists in some
regions (e.g., OSPAR). For MP, there are at present no harmonized measurements, monitoring methods,
or environmental indicators.
Although first reports on plastics in the Arctic date back several decades, the environmental fate of litter
and MP is far from understood and is a field of ongoing research. How the extreme environmental
conditions of the Arctic might affect plastic transport and degradation processes is not yet known.
Emerging knowledge from lower latitudes may not be transferable to the Arctic environment, so studies
specific to Arctic conditions are needed. The role of chemical sorption to or release from plastic particles
is a subject of research interest, and of particularly great interest in the Arctic because of important
subsistence harvesting in the region. Improved understanding of processes related to plastics in the Arctic
will be highly relevant for modeling approaches as well as risk assessments and will likely further shape
the design of monitoring activities in the Arctic.
AMAP Litter and Microplastics Monitoring Guidelines
5
1.1 Purpose of the guidelines
The purpose of the guidelines is to review existing knowledge and provide guidance for designing an
Arctic monitoring program that will track litter and MP. The topics of litter, plastic pollution, and MP are
addressed in many fora, including several of the Arctic Council working groups: Arctic Monitoring and
Assessment Programme (AMAP; https://www.amap.no/documents/doc/amap-assessment-2016-
chemicals-of-emerging-arctic-concern/1624), Protection of the Marine Environment (PAME, 2019), and
Conservation of the Arctic Flora and Fauna (CAFF). The development of an Arctic monitoring program
and its technical approaches will be based on the work that already exists in other programs such as those
of OSPAR, the Helsinki Commission (HELCOM), the International Council for the Exploration of the
Sea (ICES), the Organisation for Economic Co-operation and Development (OECD), and the United
Nations Environment Programme (UNEP).
Plastic pollution is typically categorized into items and particles of macro-, micro-, and nano-sizes. These
guidelines address macrosized litter as well as MP (< 5 mm), essentially including smaller size ranges (>
1 µm). However, determination of nanoplastic (< 1 µm) particles is still hampered by technical
challenges, as addressed in Section 4.3 Analytical methods, and thus not currently considered in the
current recommendations. Although most studies have addressed marine litter and MP, these guidelines
also comprise the Arctic’s terrestrial and freshwater environments.
Thus, the objectives of the guidelines are to:
1) support litter and MP baseline mapping in the Arctic across a wide range of environmental
compartments to allow spatial and temporal comparisons in the coming years;
2) initiate monitoring to generate data to assess temporal and spatial trends;
3) recommend that Arctic countries develop and implement monitoring nationally via
community-based programs and other mechanisms, in the context of a pan-Arctic program;
4) provide data that can be used with the Marine Litter Regional Action Plan (ML-RAP) to
assess the effectiveness of mitigation strategies;
5) act as a catalyst for future work in the Arctic related to biological effects of plastics, including
determining environmentally relevant concentrations and informing cumulative effects
assessments;
6) identify areas in which research and development are needed from an Arctic perspective; and
7) provide recommendations for monitoring programs whose data will feed into future global
assessments to track litter and MP in the environment.
To achieve these objectives, the guidelines present indicators (with limitations) of litter and MP pollution
to be applied throughout the Arctic, and thus, form the basis for circumpolar comparability of approaches
and data. In addition, the guidelines present technical details for sampling, sample treatment, and plastic
determination, with harmonized and potentially standardized approaches. Furthermore, recommendations
are given on sampling locations and sampling frequency based on best available science to provide a
sound basis for spatial and temporal trend monitoring. As new data are gathered, and appropriate power
analyses can be undertaken, a review of the sampling sizes, locations, and frequencies should be initiated.
AMAP Litter and Microplastics Monitoring Guidelines
6
Plastic pollution is a local problem in Arctic communities, and thus, guidelines and references need to
include community-based monitoring projects to empower communities to establish plastics monitoring
with comparable results across the Arctic. Community-based monitoring is an integrated part of the
objectives of this report.
The monitoring program design and guidelines for its implementation are the necessary first steps for
monitoring and assessment of litter and MP in the Arctic. The work under the AMAP LMEG is taking a
phased approach under this new expert group. The first phase (which included the development of these
Monitoring Guidelines) focuses on a monitoring framework and set of techniques for physical plastics.
Later phases of the work will extend to assessments of levels, trends, and effects of litter and MP in the
Arctic environment.
The guidelines strictly cover environmental monitoring of litter and MP. This does not include drinking
water or indoor air quality tests. Additionally, although there is an emphasis on examining litter and MP
in biota that are consumed by humans, and thus of interest to human-health questions, the guidelines do
not consider MP ingestion by humans.
1.2 Existing frameworks with relevance for litter and microplastics monitoring
Legal frameworks applicable to marine plastic pollution are complex and consist of international,
national, regional, and local policies, which cover ocean- and land-based sources of marine plastic.
Several review documents exist for policies that directly or indirectly can be applied to mitigate the
impact of marine plastic (Pettipas et al., 2016; Xanthos and Walker, 2017; PAME, 2019; Linnebjerg et al.,
2021). The United Nations recommended that current international and regional frameworks on marine
plastic pollution be reviewed to identify gaps for policy improvement (UN, 2017). Although MP in
terrestrial ecosystems have been recognized as having a potential effect on biogeochemical processes
(Rillig and Lehmann, 2020), no similar frameworks have yet been established for the terrestrial
environment.
Preventing plastic pollution from entering the marine environment is a topic of priority across the globe,
and there are a range of legally binding and non-binding international conventions that directly or
indirectly address marine debris (e.g., Kershaw et al., 2013; PAME, 2019; Linnebjerg et al., 2021). One
of the first global treaties to protect the marine environment from human activities was The London
Convention that came into force in 1975. This convention was followed by The International Convention
for the Prevention of Pollution from Ships (MARPOL), the United Nations Convention on the Law of the
Sea (UNCLOS), and The Basel Convention. Together, all of these treaties have formed the foundation of
international regulations to reduce this environmental pollutant.
The protection of specific marine environments through regional regulations plays an important role in
the concretization of international regulatory frameworks. One of United Nations Environment
Programme’s (UNEP) initiatives is The Regional Seas Programme (launched in 1974), and, in
cooperation with regional organizers, it has implemented activities related to the prevention and reduction
of marine debris that have been consolidated by legal frameworks, e.g., the Convention for the Protection
of the Marine Environment of the North-East Atlantic (OSPAR). A list of international conventions, with
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relevance to the Arctic, which addresses the reduction of marine debris is presented in Linnebjerg et al.,
2021.
Non-governmental organizations (NGOs) also play an important role in creating awareness about marine
debris. One example is the International Coastal Cleanup from the US-based NGO, Ocean Conservancy,
which removes marine debris from coastlines and collects data on the amount and types of marine debris
removed (Ocean Conservancy, 2020). The Greenpeace Call for a Plastic-Free Future (Greenpeace, 2020)
based on Zero Waste Standards and Policies (ZWIA, 2014) is another global initiative that aims to reduce
plastic waste production and consumption. For example, in Russia, this initiative has resulted in many
leading commercial networks considerably reducing the use of disposable plastic bags (Greenpeace,
2018).
For a thorough review of the policies that cover litter and MP in the Arctic see Linnebjerg et al., 2021.
Briefly, among the Arctic countries, the Kingdom of Denmark (incl. Greenland and the Faroe Islands),
Finland, Iceland, Norway, and Sweden have signed the OSPAR Convention. Denmark, Norway, and
Iceland have implemented the OSPAR seabird monitoring component, however, Sweden has determined
that monitoring fulmars is not feasible in Swedish waters. And, in Denmark and Norway, the OSPAR-
based seabird monitoring takes place outside of the Arctic. Although other Arctic countries have applied
the seabird protocol opportunistically (e.g., Canada; Poon et al., 2017), these studies are not part of a
coordinated national policy or long-term monitoring program. Monitoring programs have also been
initiated by the European Union, under the Marine Strategy Framework Directive (Galgani et al., 2013),
by HELCOM, and in a number of national initiatives, for example, under the Northern Contaminants
Program of Canada, as part of Canada’s Plastics Science Agenda (ECCC, 2019).
Importantly, policies on plastic pollution vary widely across Arctic countries. Given that plastic pollution
is subject to long-range transport, this inconsistency across the region is likely to reduce efficacy of
actions for reducing plastic pollution and for monitoring changes over time. Therefore, for policies to be
more effective, pan-Arctic coordination is required so that similar programs can be implemented in a
harmonized and consistent manner. This cooperation needs to be facilitated at both the regional and
international levels to ensure that litter and MP data from the Arctic are used in the context of global
efforts to reduce litter and plastic pollution and minimize harm to the environment.
1.3 Importance of harmonization and standardization in litter and microplastics
work
Efforts to map and categorize plastics in the Arctic have increased and coordinated monitoring under the
auspices of AMAP is envisaged. Comparability of data in litter and MP is an ongoing challenge in plastic
pollution research (Cowger et al., 2020; Provencher et al., 2020). Briefly, the term standardization refers
to the application of specific methods according to robust criteria. These methods typically have limited
flexibility to allow for comparability between laboratories. The benefit of this practice is that the
community can understand how to compare the data to assess temporal and spatial trends. The limitation
of this practice is that it significantly restricts the scientific freedom of method development. These
standardized methods are commonly applied for standard analytical procedures, such as the International
Organization for Standardization (ISO) and General Laboratory Practices (GLP) approaches.
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Harmonization means that differing methods have been rigorously tested to the point that results can be
viewed as comparable despite differences in methodologies. The benefit of harmonization is that data can
be generated across projects that employ similar, but not necessarily identical methods. Importantly, the
limitations of each method are known, and the different activities/data generated can be combined.
Comparison coefficients or scaling factors can be used when combing datasets.
There are examples in the litter and MP literature in which harmonization rather than standardization has
led to studies from different regions being compared to assess spatial trends. For example, in the North
Sea, the OSPAR Convention has developed a standard protocol for the collection and examination of
Northern Fulmars (Fulmarus glacialis) to track trends in environmental plastic pollution (> 1 mm) in the
region (van Franeker et al., 2011; van Franeker and Kühn, 2020). The North Sea protocol is based on
beached birds being examined for ingested plastics. Since the early 2000s, the protocol has been applied
to regions outside of the OSPAR, but often in regions where beached bird surveys are not possible
(Provencher et al., 2017). In regions such as Arctic Canada, collections depend on local Inuit hunters to
collect carcasses from local colonies or on fishers submitting fulmar incidentally caught in their nets.
Although the collection methods are different, harmonization has been achieved and allows comparisons
across and between larger regions. Researchers in the region have worked with international colleagues to
ensure that methods are harmonized and thus can contribute to reporting standardized, comparable data
across the northern hemisphere (Provencher et al., 2017).
Unfortunately, there are limited standardized methods for determining and assessing litter and MP in
samples, although work is ongoing under ISO on standardized approaches for MP. Therefore, at this time,
the litter and MP community is striving to harmonize methods in real time to compare levels and trends
around the globe. We encourage the Arctic litter and MP community to engage in these global efforts to
ensure comparability across studies. This includes global efforts to define methods, standard reference
material, interlab comparisons, and suitable controls. Several efforts have focused on such harmonization,
including those of the UN’s Joint Group of Experts on the Scientific Aspects of Marine Environmental
Protection (GESAMP), and the Marine Strategy Framework Directive (MSFD) Technical Group for
Marine Litter. Although the focus of these guidelines is the Arctic, it is important to recognize these
global efforts so that any data collected in the Arctic on litter and MP are comparable globally and useful
in larger litter and MP assessments. Thus, the following technical sections covering litter and MP
methods in abiotic and biotic compartments are aiming for harmonized methods, which in some cases,
may lead to standardized methods.
A monitoring program should provide concentrations of a target analyte in the medium, representative of
the location and time of sampling. General issues to be considered are (1) definition of the target analyte
in the case of plastic litter and MP, (2) detection limits (and other parameters describing data quality), and
(3) detectability of temporal and spatial trends. Because national monitoring initiatives for plastic litter
and MP should feed into circumpolar AMAP assessments, it is essential that they produce comparable
data.
Plastics occur in a number of sizes, shapes, colors, and materials. As addressed above, the guidelines
include all sizes of litter and plastics. Shapes include fibers, films, foams, beads, etc., also giving some
indication of original products or materials. It is common practice to report a number of plastic particles
or a mass of plastics per sample mass or volume, usually for a certain size range and/or for certain shapes.
AMAP Litter and Microplastics Monitoring Guidelines
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This alone introduces variability in reporting, which makes comparisons between studies difficult.
Weathering processes can have an impact on the number and characteristics of plastic particles. In
addition, a plastic sample can include several types of synthetic polymers. This means standardization in
terms of what is measured and reported is important, i.e., a definition of the target analytes.
Plastic materials are omnipresent in everyday use, and thus contamination of samples (and reporting of
false positives) is a serious risk in all steps of sample handling. Any contamination and background levels
also have direct impacts on the detection limits of the monitoring program. Therefore,
standardized/harmonized measures must be taken to minimize this risk and to monitor potential
contamination. Similarly, other parameters describing data quality, such as measurement uncertainty, will
be affected by random contamination.
The importance of standardization and harmonization also applies to methods of sampling, storage and
transport, sample processing, analytical determination, and quality assurance/quality control (QA/QC). In
all steps, variability can be introduced. In general, knowledge of these sources of variability is still limited
and will be explored further in the guidelines. The variability in the sampling and analysis has direct
consequences for the detectability of temporal and spatial trends because large uncertainties will affect
their statistical power.
1.4 Examining litter and microplastics across the Arctic
The following sections discuss litter and MP in 11 environmental compartments: air, ice/snow, terrestrial
soils, aquatic and shoreline sediments, beaches, water, seabed litter, invertebrates, fish, seabirds, and
mammals. These compartments span several Arctic ecosystems (e.g., tundra, lakes, rivers, coastlines,
subtidal). Data from these compartments can be used to document the presence of a range of size classes
of litter and MP in the environment and to improve the understanding of underlying processes.
For each of these environmental compartments, the following sections review the state of knowledge in
the relevant compartment and identify a suite of primary and secondary monitoring indicators that have
been described in relation to (1) the current state of methodologies (in each compartment) and (2) the
feasibility for their use in monitoring initiatives across the Arctic. Primary monitoring indicators are those
within each compartment that can be implemented immediately with current protocols and technologies
to inform future litter and MP assessments in the Arctic. For example, examination of stomach contents in
Northern Fulmars is the primary indicator identified in the seabird section for immediate implementation
where possible.
Secondary monitoring indicators are those within each compartment that are viewed as needed for a
holistic understanding of litter and MP in Arctic ecosystems but need further efforts to develop
methodologies before being implemented at the pan-Arctic level. For example, in the seabird
compartment, gut analysis of other species, as well as nest incorporation of litter are listed as secondary
indicators that require more development before widespread implementation.
Some secondary monitoring indicators may also serve other specific monitoring purposes, for example,
effect monitoring in relation to chemicals associated with plastic pollution that are of wide interest. The
primary and secondary monitoring indicators are also thus linked to different types of monitoring with the
AMAP Litter and Microplastics Monitoring Guidelines
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main focus on baseline establishment, trend monitoring, and source/surveillance monitoring. Importantly,
in each compartment, these primary and secondary monitoring indicators also address the actions outlined
in the Marine Litter Regional Action Plan (ML-RAP).
Photo: Maria E. Granberg
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2.0 Guidance for Monitoring Abiotic Environmental Compartments
2.1 Wet and dry atmospheric deposition
AUTHORS: LIISA JANTUNEN AND DORTE HERZKE
2.1.1 Introduction and description of purpose/aims of monitoring
Even with major research efforts happening on marine plastic pollution, the PAME report identified
atmospheric circulation as a pathway to marine pollution still lacking in empirical data (PAME,
2019). Because there are only sporadic data available at this point and no harmonized methodology,
no global estimate on the magnitude of atmospheric transport of microplastics (MP) to the Arctic is
available. Nor will it be available in the near future. Additionally, local sources have not yet been
investigated, thus the delocalization of macroplastic waste from landfills and urban settlements during
storms is a possible route of transport within short distances (PAME, 2019).
Due to the still experimental nature of atmospheric sampling and the small number of peer-reviewed
publications describing validated methods, no final recommendations on robust procedures are
possible at this time. As an alternative, until validated methods are available, we are reporting on
methodology by relevant publications and recommending best practices.
Like their marine counterparts, atmospheric MP consist of a variety of polymer types (Enyoh et al.,
2019). Their morphologies show a similar variety of forms such as fragments, foams, films, granules,
fibers, and microbeads (Enyoh et al., 2019), with fragments and fibers being the dominant MP (Dris et
al., 2016, 2017; Cai et al., 2017; Zhou et al., 2017; Catarino et al., 2018; Allen et al., 2019; Ambrosini
et al., 2019; Liu et al., 2019a, b). Allen et al. (2020) found that seaward winds had higher levels of MP
associated with them than land-originating winds, suggesting that sea spray contributes to the
atmospheric loads of MP.
Like marine MP, atmospheric MP may consist of up to 70% of additives and contaminants (Rummel
et al., 2019). A recent report on nanoplastics in high altitude alpine snow indicates airborne transport
of very small plastic particles that have unknown environmental and health impacts (Materić et al.,
2020). Therefore, research on MP and especially microfiber transport in remote regions, like the
Arctic, is utterly important in determining the dispersion of MP so that all aspects of their
environmental impacts can be assessed.
Within the frame of atmospheric MP occurrence, three groups of MP distribution can be
distinguished:
i) wet deposition (mist, rain, and snow),
ii) dry deposition (dust), and
iii) suspended particles.
Microplastics in snow and ice on land are a direct result of atmospheric deposition combining wet and
dry deposition (Ambrosini et al., 2019; Bergmann et al., 2019; Geilfusa et al., 2019); however, it is
unknown if precipitation or snow deposits are a good proxy for deposition of airborne MP. In places
like the Arctic, precipitation can vary substantially locally and is especially low in the desert-like
conditions of the Canadian High Arctic. Precipitation is higher in the European Arctic.
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Sea ice is not a good proxy for air pollution because sea ice will incorporate MP and microfibers from
seawater into the ice. Microplastics in sea ice and snow on ice are discussed in Section 2.5, whereas
land-based precipitation is covered in this section.
Compared to ocean currents, air currents can distribute atmospheric particles very quickly, within a
matter of hours and days (Stohl, 2006). Like other atmospheric particles, MP are expected to undergo
long-range transport in air currents followed by wet and dry deposition onto water and land (Allen et
al., 2019) and will also undergo changes in the atmosphere, including hydrolysis, UV degradation,
accumulation of organic films, and aggregation with other particles (Gewert et al., 2015).
Microplastics may also fragment into smaller pieces in the atmosphere, most likely increasing their
long-range transport abilities (Biber et al., 2019). Microplastics vary in densities and shapes, causing,
for example, microfibers to be more likely to travel longer distances than other MP because both the
diameter and length matter for atmospheric transport (Allen et al., 2019; Zhang et al., 2020). In
general, the atmospheric dry and wet deposition, or “fallout,” as some plastics’ publications
erroneously refer to it, has not been well quantified as to its contributions to aquatic and terrestrial
environments.
Local sources also exist in the Arctic, with short-range transport being relevant even with sparse
populations. The contribution of local and long-range transport sources to MP in the Arctic are not
quantified at this time.
2.1.2 Summary of available information/existing monitoring frameworks
The nature of atmospheric MP sampling and analyses is still in its infancy; thus, a number of locations
have been investigated applying mostly experimental sampling methods. Reports from Europe (Dris
et al., 2015, 2016, 2017; Catarino et al., 2018; Allen et al., 2019; Bergmann et al., 2019; Klein and
Fischer, 2019; Vianello et al., 2019), China (Cai et al., 2017; Zhou et al., 2017; Liu et al., 2019a, b),
Iran (Dehghani et al., 2017; Abbasi et al., 2019), and the Pacific Ocean (Liu et al., 2019b) have been
published on airborne MP and reviewed by Zhang et al. 2020. The MP deposition, in the above
studies, ranges from 1.5-221 MP/m2/day. Of the conducted studies, atmospheric MP were found in a
range of different compounds and morphologies akin to their marine counterparts. Abundance across
studies varied considerably, and collectively they provided little information about size ranges and
chemical composition.
The occurrence and distribution of suspended atmospheric MP (SAMPs) in the western Pacific Ocean
provide field-based evidence that MP in the air can act as an important source of MP to the ocean (Liu
et al., 2019b).
So far, there are no standard sampling and particle quantification/identification procedures for
airborne MP. Further, reported sampling methods vary depending on indoor or outdoor sampling, as
well as on whether measuring wet or dry deposition. A selection of reported sampling techniques is
listed below:
Atmospheric microplastics
o Atmospheric deposition sample: passive air sampling using wet and/or dry deposition
collector
Wet deposition sample: no data for wet deposition alone
Dry deposition sample: indoor air (Dris et al., 2016)
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Dry/wet combined deposition sample: urban (Dris et al., 2015, 2016; Cai et al., 2017),
alpine catchment (Allen et al., 2019)
o Suspended air sample: active air samples using the pumps (low/middle or vacuum pump)
equipped with particle filtering parts or mist sampler
indoor (Dris et al., 2017), urban outdoor (Kaya et al., 2018), suspended road dust
(Abbasi et al., 2019), Northwest Pacific Ocean air (Liu et al., 2019), coastal air (Allen
et al., 2020)
coastal mist using an active strand cloudwater collector (Allen et al., 2020)
o Samples deposited on the surface: exclusive atmospheric-driven samples collected from the
surface
deposited road dust (Abbasi et al., 2019), alpine and Arctic ice floe snow (Bergmann
et al., 2019), alpine snow (Materić et al., 2020)
Monitoring airborne MP throughout the year in the Arctic is important to assess the impact of
seasonal changes in wind patterns and the presence of UV light, as well as the impact of sea spray on
atmospheric levels of MP and nanoplastics in both air and water (Allen et al., 2020).
Recommended particle size range for air sampling is 10-500 µm (although larger sizes should not be
excluded) because the highest proportion of reported MP are < 500 µm (Enyoh et al., 2019; Zhang et
al., 2019, 2020). For snow in European and Arctic regions, 98% of all MP were < 100 μm (Bergmann
et al., 2019).
The lack of standardized active and passive sampling methods is hampering the comparability of
studies, so no recommendations based on validated procedures and practices can be made at this time.
However, strict quality assurance/quality control (QA/QC) procedures need to be followed to ensure
reliable data, preferably carrying out sample treatment in a cleanroom or a laminar flow cabinet. To
the extent possible, plastic-containing equipment should be avoided during field and lab activities (see
subsection 2.1.6 for more details on QA/QC).
Chemicals transported by microplastics in air
As with MP found in the marine environment, both adsorbed pollutants as well as additives are part of
atmospheric MP’ chemical make-up. A broad range of analytical methods are available to determine
the composition and concentrations of these chemicals (see earlier sections for more details). In
general, adsorbed components (organic and inorganic, i.e., metals) are present at much lower
concentrations compared to the additives, thus requiring ultra-trace analytical methods, whereas
additive determination relies on the availability of a multitude of analytical techniques and
instrumentations.
2.1.3 Trends in literature in Arctic regions
Atmospheric microplastics
So far, no atmospheric field studies have been conducted in the Arctic. The most recent examples for
wet deposition are studies that reported MP in Arctic snow (Bergmann et al., 2019) and in alpine
snow (Allen et al., 2019; Ambrosini et al., 2019; Materić et al., 2020). A recent modeling study
(Evangeliou et al., 2020) globally simulated atmospheric transport of MP particles produced by road
traffic (TWPs, i.e., tire wear particles and BWP, i.e., brake wear particles). The authors found high
transport efficiencies of these particles to remote regions, suggesting that the Arctic is a particularly
AMAP Litter and Microplastics Monitoring Guidelines
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sensitive receptor region because of the light-absorbing properties of TWPs and BWPs, which cause
accelerated warming and melting of the cryosphere (Albedo effect; Evangeliou et al., 2020).
Chemicals transported by microplastics in air
Microplastics, volatile siloxanes, and organophosphate esters share the same hotspot regions in the
Canadian Arctic, indicating similar sources, possibly undergoing the same transport processes caused
by their shared origin from plastics (Panagopoulos Abrahamsson et al., 2020; Sühring et al., 2020;
Adams et al., 2021).
2.1.4 Benefits and limitations
Benefits
Conducting research in the Arctic for atmospheric MP is crucial for the evaluation of their
distribution, sources and fate, contribution of local and remote sources, and how they will affect the
Arctic. Further, we need to understand how atmospheric MP are contributing to marine MP loads
because of their differing types, sizes, and chemical loads due to their different emission sources,
transformation processes, and fate history.
Further, the improved understanding of local and long-range transport sources will assist in the
formulation of legislation and remediation measures. Microplastic concentrations in indoor air are
both important for the estimation of human exposure as well as for elucidating sources to MP in
outdoor air. This is especially important for people living in the Arctic, who, due to harsh
environmental conditions, stay indoors for long periods of time and have very well insulated homes
with little air exchange.
The determination of chemicals added and sorbed to atmospheric MP would improve the knowledge
base on their role as a vector for chemicals into the Arctic environment.
As climate change impacts the Arctic, melting ice and changes in atmospheric circulation patterns,
primary and secondary emissions of MP, and, especially relevant to air, microfibers need to be
investigated to determine the current transportation trends to, within, and out of the Arctic so changes
and impacts can be estimated. Also, more extreme weather conditions will cause more physical
damage to MP, as well as mixing between water and airmasses, further adding to the MP load in the
atmosphere.
Limitations
Aside from the unavailability of a consensus on the applied methodology, the monitoring of
atmospheric MP in the Arctic is highly limited by the remoteness of sampling locations and the
challenges of the infrastructure. This is especially true for Arctic regions in Russia and North
America, where the population is sparse and travel to and within is limited, difficult, and expensive. It
is important to sample year-round to assess the seasonal changes in atmospheric circulation and
transport of MP to the Arctic from different regions of the world. A representative sample size as well
as the number of required replicates is a prerequisite for a valid method to collect a sufficient amount
and a sufficient number of subsamples to adequately represent the sampled location.
Another limitation is the unavailability of highly trained and skilled operators, which are needed to
effectively collect samples to reduce the risk of contamination and ensure a rigorous sampling regime.
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Although all sampling, analyses, and polymer determination are very time consuming, requiring
trained personnel and expensive instrumentation, the very small size of atmospheric MP make it even
more prone to contamination during processing and analysis, thus requiring lab facilities with particle-
controlled environments as a prerequisite for atmospheric sample analyses.
Other specific limitations include access to electricity for active air, and wet and dry only deposition
sampling because the quantitative nature of active air sampling results in more reliable data than
passive sampling in a shorter time frame. Limitations can be overcome by co-deploying active air, wet
only, and bulk samplers at a few stations to assess their comparability. For example, in Canada, the
Alert monitoring station, and in Svalbard, the Zeppelin station would be good candidates to assess
this.
Wet only and bulk deposition sampling limitations in the Arctic include strong winds, e.g., blowing
the particles out of the sampler, and the varying amounts of snow fall across the Arctic, e.g., some
regions with large amounts of snow may bury the sampler whereas in other regions, desert-like
conditions exist with very little snowfall in a season.
For all types of samplers left in the field, there is the potential for wind, snow, and animal damage to
the equipment. Due to extreme weather conditions in the Arctic, the lack of consistent access to
sampling equipment may also be a limitation.
2.1.5 Sampling strategy and methodology
Sampling strategy: There are limited options to collect air samples in the Arctic for MP because of the
remoteness of sites, harsh conditions, and limited access to power. Typical sampling includes active
air samplers, bulk deposition samplers, and wet deposition samplers. Active air samples will provide a
quantitative number of particles per meter cube of air; however, active air samplers for air monitoring
networks are expensive, require power, require an operator to change filters, and give data over a very
short time snapshot of the air. Passive samplers, advantageously, can be installed at existing
atmospheric monitoring sites in the Arctic, reducing the need for manpower and infrastructure. Bulk
deposition samples give a total of wet and dry deposition without the need for power, can be
integrated over a longer period of time (e.g., typically one week or one month); whereas, wet only and
dry only samples give more detailed information but require power and a specialized sampler. To
their disadvantage, bulk deposition and dry deposition samples overestimate the size of atmospheric
particles because larger particles settle out more quickly, and smaller fibers stay suspended in the air
for a longer time. If smaller particles do settle out, they may become re-suspended in the air more
easily than larger particles (Rezaei et al., 2019). Wet deposition samples probably provide a better
representation of the atmospheric load of MP because precipitation washes the air column of particles,
however in all cases of bulk deposition analyses, a quantitative evaluation of airborne particles is
challenging. Outdoor passive air samplers are being developed and tested but results have yet to be
released.
For both alternatives, the co-location at existing monitoring sites is highly beneficial because it
enables the simultaneous delivery of supplemental data on other atmospheric measurements, also
enabling back-trajectory analysis of possible sources, event-analyses, and input in databases and
modeling actions. These types of sampling networks are sparingly distributed in the Arctic, but at key
locations.
AMAP Litter and Microplastics Monitoring Guidelines
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Independent of the sampling method chosen, sampling for atmospheric MP should be continuous
throughout the year, covering shorter periods of time, to give insights into seasonal changes of wind
patterns and any short-term transport events.
Replicates: It is difficult to collect replicate active air, wet only, and dry only samples because of the
power and duplicate samplers’ requirements but replicate bulk deposition samples are encouraged.
Nipher gauges are a well-established method of collecting snowfall in higher wind environments. A
type of bulk air deposition sampler that buffers the wind and limits resuspension of particles from the
sample is encouraged.
Not recommended:
1) Air sampling, including deposition sampling, from ship-board platforms is not recommended.
Ships are a source of contamination to the surrounding air because they vent substantial
amounts of air from their systems including engine, HVAC, and laundering exhausts, which
contain MP that would contaminate air samples. However, a wind-sectoring system can collect
the air inflowing from the head of the ship and can exclude the collection of air inflowing from
the other sides of the ship. This system can be used to prevent ship-based contamination.
2) Grab snow sampling, especially one-time opportunistic sampling, is not recommended. Snow
sampling gives a snapshot of the MP in snow, but it is impossible to determine the age and
history of the snow if no additional parameters are measured, or if fresh snowfall is collected.
As an alternative, bulk deposition samplers are recommended. Ice/snow cores from overland
are encouraged especially if paired with other chemical analyses that provide ancillary data
when interpreting the MP data. Ice cores from over water are discussed in Section 2.2.
3) Opportunistic sampling is not recommended except when rigorous QA/QC are maintained.
4) Subsampling is not recommended because MP are not homogenously distributed within the
sample.
Sample treatment
It is recommended to process the samples as little as possible to avoid contamination, together with
storing the samples in plastic-free, precleaned containers. Digestion steps can fragment the particles
and fibers, biasing the number and size distribution of the MP, and are generally not needed for
atmospheric-related sampling, although there are exceptions.
More processing steps expose the samples to more sources of contamination, which are critical to
avoid because of the small particle sizes in air. As with other MP sampling, all water used for rinsing
must be HPLC grade or Milli-Q water and DIW that have undergone additional filtration using the
same filter types as with sampling to remove plastics from the water filtering system. Specific to bulk,
dry, and wet deposition, sample collectors must be rinsed thoroughly to remove MP from the walls of
the sampler and subsequently filtered with filters applicable to the research question and measuring
technique (pore size, diameter, material). For active air samples, direct transfer of the filter to the
analytical instrumentation with no processing is recommended. If not possible, due to high particle
loads, e.g., no monolayers can be ensured, particles need to be re-suspended by ultrasonification in
water, subsampled, if necessary for higher load samples and filtered. Although ultrasonification may
cause particles to fragment, so it should be minimized.
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Sample analyses
It is imperative that particle specification methods are included, for example, polymer type, shape,
length, and diameter. Sample analyses should include microscopy and fluorescence microscopy, if
using Nile Red, paired with Raman spectroscopy and/or µFTIR to screen suspected MP. As an
inexpensive, fast screening method, staining with lipophilic Nile Red can be chosen for identification
of larger MP > 20 µm (for rapid screening under a fluorescence microscope; Maes et al., 2017). That
being said, Nile Red cannot determine polymer type and disagreement within the MP community
about the usefulness of Nile Red treatment does exist.
Samples should only be subsampled when there are substantial particle loads, preventing a monolayer
of particles on the filter, disabling the identification of the particle composition. No homogeneity of
particle distribution can be assumed in the sampler and/or filter. Also, high particle load is not typical
in atmospheric related samples in remote Arctic regions.
Because the availability of analytical methodology for particles < 20 µm is limited, it is important to
subset and archive samples when possible in a contamination-free, dark, and cool environment (< 15
oC). However, the low levels of atmospheric MP in the Arctic may limit subsampling and the limited
access to samples may limit the ability to sample archive.
2.1.6 Quality assurance/quality control (QA/QC) and reporting/data management
Here we discuss QA/QC as it pertains to atmospheric related sampling (see also Brander et al., 2020
for a wider discussion of MP QA/QC protocols).
Harmonized terminology: To mitigate inconsistent terminology and to enable translation of the data to
atmospheric particle research in general, terminology defined in atmospheric science should be used.
Sampling: Opportunistic sampling should be avoided except for research purposes, and to ensure a
wide data comparability, systemic sampling and handling should be maintained. Replicated samples
are highly recommended and should be considered when possible. Clothing worn during sample
media preparation, collection, and recovery must be documented.
Contamination: The sizes of particles in air are, in general, smaller than other matrices, therefore, it is
very important to follow stringent QA/QC procedures. Field, travel, and laboratory blanks are crucial
steps to track and eliminate contamination. For field blanks (the sample collection containers are
opened during sample collection), it is recommended that a representative number of field blanks and
procedural blanks are taken (one blank per field sample or per sampling period). For travel blanks
(sample collection containers are not opened in the field), it is recommended to take 1 blank per 10
samples. For laboratory blanks, three lab processing blanks per processing day should also be done.
These blanks form the basis for the limit of detection, method detection limit, and limit of
quantification so an evaluation can be made to ensure reported values in samples are statistically
greater than the blanks. These values must be defined by the group reporting the data.
Strict routines for choice and preparation of sampling equipment (plastic free, fired at 450 oC for > 4
hours) need to be followed, and the handling of samples under particle-controlled conditions (laminar
flow fume hood with filtered air/clean room) is essential. A consensus needs to be developed on how
field blanks are included and how blank subtractions are performed.
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Recoveries: Spike recovery tests are highly recommended and are performed by adding a known
number of particles (of several sizes) to blank filters and these are then processed as actual samples.
These samples can also be used as blanks for other particles not intentionally added. As standard
reference materials are developed, it is recommended that laboratories assess method efficiency by
using them. Participation in intercalibration studies or round robin exercises is also strongly
encouraged.
Reporting: Standardized methods for instrumental analysis and reporting (number, weight, size,
length, and diameter) need to be developed. When reporting data, especially on microfibers, the
length but also the diameter is important because both these dimensions have impacts on the transport,
fate, and inhalation rate. Using more than one analytical technique to assess the presence and identity
of plastic particles is important because microscopy, Nile Red, Raman spectroscopy, and FTIR
methods used on their own, yield different types of information. Using these methods simultaneously
can yield better interpretation of results but will increase the time spent on each sample dramatically.
As sample scanning instrumentation becomes more widely available and used, the sample processing
time will decrease. In general, facing a particle size range of nm to µm, dedicated requirements for the
inclusion of MP data into existing databases for atmospheric pollution should be considered. The
advantages of combining atmospheric MP data with already collected data on many other atmospheric
pollutants and descriptors are considerable (e.g., EMEP, EBAS). This also includes the translation of
particle abundance, reported in particle counts, into weights.
2.1.7 Existing monitoring for populations/contaminants in the Arctic
Currently, there are no standardized and/or harmonized monitoring methods for air available with
only very limited reports of atmospheric MP, and no reports in the Arctic. Current active air sampling,
passive sampling, bulk deposition, wet deposition, and dry deposition methodology need to be
adapted to Arctic conditions and requirements for robust and reliable data.
2.1.8 Suggestion for future activities/knowledge gaps
The area of atmospheric MP is still in its infancy with many data gaps and a less than robust database,
hampering any conclusions on the role of the atmosphere in Arctic MP pollution.
However, experiences and lessons learned from the well-developed research on marine MP can be
used and adapted especially with respect to sample handling, QA/QC, quantification, and
identification of MP.
The recent report published by PAME, 2019 identified the following gap: “Atmospheric Transport -
There is a big research gap with no current studies being able to quantify plastics from long-range
winds, and other air-based vectors.” Although this report also recommends sampling ice floes to
improve estimates of atmospheric transport of litter, we do not recommend this because ice floes have
atmospheric sources but also incorporate plastics from water and sea spray (Allen et al., 2020), so
assuming the MP in ice floes are only from atmospheric deposition would lead to an overestimate of
atmospheric deposition.
Field measurements of known emission sources have yet to be undertaken. Primary and secondary
emissions redistribute MP back into the air from seawater as waves break (Allen et al., 2020) and/or
they may be suspended from terrestrial surfaces by wind (Rezaei et al., 2019). Melting sea ice and
AMAP Litter and Microplastics Monitoring Guidelines
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glaciers can also lead to a redistribution of atmospheric MP. Studying the depositional fluxes at the
air-water interface is essential for investigating MP behavior in dynamic systems (Galgani and
Loiselle, 2019) and to estimate the loadings of atmospheric-related particles to land and sea surfaces.
Particles undergo deposition onto water and land surfaces, however, the behavior and fate of MP on
water surfaces will differ from deposition on land.
Trajectory models should be applied to determine the trends of long-range transport vs. local transport
and to evaluate event-based transport. Trajectory models and other atmospheric transport models
could lead to insights on the emission sources of airborne MP. Field measurements need to be carried
out complementarily, to both validate the transport models and to identify relevant sampling locations
and periods, saving time and effort. This work needs to be coupled with experimental determination
of aerodynamic features of MP and microfibers to feed correct variables into the model describing
their atmospheric transport using existing global distribution models.
The presence of other anthropogenic microfibers, e.g., cellulose fibers that are associated with
anthropogenic dyes and/or chemicals in atmospheric-related samples, is also worth documenting
when undertaking MP analysis. Cellulose fibers such as cotton, rayon, linen, and hemp are highly
processed and contain up to 30% added chemicals, which may enhance their persistency in the
environment; e.g., cellulose fibers from blue jeans are found in deep Arctic ocean sediments (Athey et
al., 2020).
AMAP Litter and Microplastics Monitoring Guidelines
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Table 2.1 Monitoring and research recommendations divided into must do and should do.
1st level (must do)
2nd level (should do)
Monitoring
Bulk deposition (wherever
possible, duplicates wherever
possible), one week integrated
sample
Wet deposition at one-two
locations per region, where
existing stations and power
source are available; one week
integrated sample
Active air sampling at one-two
locations per region where
existing stations and power
source are available, > 2500
m3
Must have data:
Location
Date
Collection method
Polymer type
Particle number/weight,
length, diameter, shape, color
Subsampling and archiving of
samples when possible
Context
< 500 µm although larger
particles will also be counted
Active air: particles/m3
Bulk deposition:
particles/day/m2
wet deposition: particles/L
when using pyr-GC/MS or
other destructive methods for
small particle size ranges (<
20 µm), weight-based
reporting is encouraged (µg/
L/ m2/ m3)
Locations: see map
Dry only deposition
Must have data:
Location
Date
Collection method
Polymer type
Particle length, diameter,
shape, color
Context
< 500 µm although larger
particles will also be counted
Dry deposition:
particles/day/m2
Research
Relate to other classes
Best filters to be used for
active air sampling
Sampling amounts and
periods
Sampler design
Cross-contamination issues
Determination of MP
composition
Methods for measuring
chemical compounds related
to MP (additives)
Suitable instrumentation
Relate to additional
atmospheric data
AMAP Litter and Microplastics Monitoring Guidelines
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Table 2.2 Summary rationale for recommendations, including estimated costs for implementing
programs; 0 - litter and plastic pollution monitoring already in place with regular funding; $ -
relatively inexpensive because new litter and microplastic monitoring programs can use existing
programs to obtain samples in at least some regions, but need to have some additional capacity to
process samples for litter and plastic pollution; $$ - either sampling networks and/or capacity need to
be developed to monitor litter and microplastic pollution; $$$ - development of sampling networks,
processing capacity of samples, and reporting all need to be developed in the majority of the Arctic
regions.
Recommendation
Program Cost
Rationale
Primary Recommendations
Bulk deposition (wherever
possible, duplicates wherever
possible).
$
This sampling type can be easily set up at
existing sampling sites or in northern
communities. It may involve some money to
purchase supplies, shipping, and training the
operator.
Wet deposition at one-two
locations per region, where
existing stations and power
source are available.
$$
Existing research programs are already in place at
sites throughout the European and Canadian
Arctic but there are still substantial costs
associated with this type of sampling: the
shipment of equipment to remote locations,
installation of the sampler, a required power
source, and an operator.
Active air sampling at one-
two locations per region
where existing stations and
power source are available.
$$
Existing research programs are already in place at
sites throughout the European and Canadian
Arctic but there are still substantial costs
associated with this type of sampling: the
shipment of equipment to remote locations,
installation of the sampler, a required power
source, and a skilled operator to calibrate the
pump and change the filters.
Secondary Recommendations
Dry only deposition.
$$
Existing research programs are already in place at
sites throughout the European and Canadian
Arctic, less so in Russia but there are still
substantial costs associated with this type of
sampling: the shipment of equipment to remote
locations, installation of the sampler, a required
power source, and an operator.
AMAP Litter and Microplastics Monitoring Guidelines
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AMAP Litter and Microplastics Monitoring Guidelines
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AMAP Litter and Microplastics Monitoring Guidelines
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2.2 Water
AUTHORS: AMY L. LUSHER, INGEBORG HALLANGER, BJØRN EINAR GRØSVIK, AND ALESSIO GOMIERO
2.2.1 Introduction
The first assessments of plastic in the global oceans were based upon items floating on the ocean
surface or immediately below. The ocean surface accounts for most studies conducted on plastic
pollution to date. This is likely in part because roughly half of all plastic produced is less dense than
seawater and expected to float at sea (Geyer et al., 2017) and partly because water is one of the easiest
and cheapest domains to study. We are now fully aware that plastics of various sizes are everywhere,
and all water bodies, either freshwater or marine, can be sampled to study the presence of plastics
from surface waters or within the water column.
The broad distribution of plastics is assumed to be related to their longevity in the environment; they
degrade very slowly, mainly through mechanical abrasion and exposure to UV radiation. Water
surfaces and the upper water column (especially in the sea) are very dynamic and provide a
connection between coastal, inland waters, and offshore areas facilitated by water movement and
transport patterns and processes. The relatively high buoyancy of many plastics facilitates transport
from source areas, which may involve long-distance or even global-scale transport. Floating plastics
can also be transported vertically. Many processes are involved in vertical displacement including
density, buoyancy, size, degradation, biofouling, and other biological interactions. As a result, we are
now aware that plastics move between water compartments because of their physical, mechanical, and
biological properties (Choy et al., 2019; van Sebille et al., 2020).
The inclusion of plastics in water monitoring programs must consider this complex scenario and focus
on useful and affordable actions to collect time series, which are the primary tool to verify whether
remediation actions are effective.
Sampling strategies for monitoring must relate to the specific goals of the monitoring program. For
example, does one want to investigate accumulation areas, input related to point sources (e.g.,
effluents from wastewater treatment plants or industries), input from freshwater water ways (rivers,
creeks, etc.), or long-range transport? The sampling methods available for each program may be
different depending on which compartment and which size of plastic is being monitored. Further, the
selection of sampling location may be constrained by the facilities and infrastructure available to
specific nations. Other important aspects that might need to be considered are the inherent properties
of the chosen environment as well as the sampling season. For example, surface sampling nets are
impractical in open waters when there is high biomass, adverse weather conditions, and sea ice.
Critical analysis of methods and many general considerations about monitoring have been highlighted
by many working groups at a global scale, some of them are reported in subsection 2.2.3, but they
were not specific to the Arctic. We therefore focus on the specific issues that are relevant for the
Arctic to implement global, general-use recommendations for local application.
2.2.2 Status of global science
In polar regions, records of plastic pollution in the Arctic date back to the 1960s, with some
observations of plastic debris and relative consequences for marine life from Alaska (Threlfall, 1968).
Large floating plastic items have been observed at sea dating back to the 1970s, and included plastic
AMAP Litter and Microplastics Monitoring Guidelines
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bottles, ropes, balloons, and rubber shoes (Venrick et al., 1973). Similarly, researchers began
sampling small plastics from oceanic surface waters around the same time (Carpenter and Smith,
1972). Long-term data sets have emerged from the Pacific (Law et al., 2014) and Atlantic (Law et al.,
2010), as have numerous global ocean models (Mountford and Morales Maqueda, 2019; van Sebille
et al., 2020). Freshwater water bodies are comparatively less studied (Mendoza and Balcer, 2019).
In terms of the Arctic, large plastic items are routinely reported floating in the surface waters of the
Barents Sea and Fram Strait (Bergmann et al., 2016; Grøsvik et al., 2018). Norway and Russia have a
long-term collaboration of monitoring fish resources in the Barents Sea used for determining fisheries
quotas, and from 2004, this monitoring was extended to include ecosystem-based monitoring. From
2010, the monitoring also included recording floating marine debris and litter as bycatch in trawls.
The ecosystem survey in the Barents Sea covers a station net of approximately 300 stations and is
performed between August-October each year (Eriksen et al., 2017). Similarly, in the Canadian
Arctic, at-sea surveys of seabirds have been expanded to include floating marine debris (Mallory et
al., 2021).
Specific investigations targeting microplastics (MP) in the Arctic began by using vessels of
opportunity to collect data from offshore seawater (Lusher et al., 2015; Kanhai et al., 2018, 2020), as
well as surface sampling using, e.g., manta nets (Cózar et al., 2017). There are historical records of
small plastic items captured in surface sampling nets dating back to the 1970/1980s in the Bering Sea
and the Gulf of Alaska (e.g., Shaw, 1977; Day and Shaw, 1987; Day et al., 1990). Research vessels
often have an underway seawater pump, positioned in the subsurface waters to collect information
such as temperature, salinity, and conductivity. Lusher et al., 2015 used this to collect back-to-back
samples while a research vessel was on a transect from northern Norway (Tromsø, 69.65° N, 18.95°
E) to the south west of Svalbard (78.1° N, 18.8° W). They also collected manta net samples (> 330
µm) along the same route intermittently. The average number of particles collected using the pump
was 2.68 ± 2.95 particles per m3 (range 0.00-11.5 particles per m3), whereas the manta net results
yielded lower values, 0.34 ± 0.31 particles per m3 (range 0.00-1.31 particles per m3). Similarly, Cózar
et al. (2017) demonstrated how manta nets could be used to collect information on plastics floating in
the surface waters during a circumpolar expedition. Out of the 42 samples collected, plastic debris (>
500 µm) were generally scarce, however the investigation did point to higher concentrations in the
Barents Sea and Greenland areas compared to the other regions of the Arctic. Additional manta net
investigations have been carried out in the Bering Sea (0.091 ± 0.094 particles per m3), Northern
Pacific (0.030 ± 0.017 particles per m3), and Chukchi Sea (0.23 ± 0.07 particles per m3; Mu et al.,
2019). To date, the most northerly manta net sample has been carried out close to the edge of the
North Pole ice shelf at 82°07’ N (Aliani et al., 2020).
Nets are selective for some size classes of MP and miss relevant parts of the mass of floating
megaplastic size class. They also fail to sample many particles smaller than the lower mesh size,
which typically is dominated by smaller MP fragments and microfibers. This is evidenced by a recent
study carried out in Nuup Kangerlua, a fjord in West Greenland (Rist et al., 2020). Pump sampling (5
metre depth, 10 µm lower limit) and bongo nets (surface, 300 µm lower limit) produced values with
two orders of magnitude difference. Therefore, integration with pump and bucket sampling is
envisaged to cover as many size classes as possible (Ryan et al., 2019) and is becoming more and
more common in oceanographic expeditions.
Pump sampling was also used by Morgana et al., 2018 and Jiang et al., 2020 who reported values
similar to those found by Lusher et al., 2015, confirming the ubiquitous presence of MP in the
AMAP Litter and Microplastics Monitoring Guidelines
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Greenland Sea. Higher levels of MP were reported in surface waters underlying ice floes, 0-18
particles per m3 (Kanhai et al., 2020). On the contrary, during an investigation of different water
masses in the Arctic Basin, Kanhai et al. (2018), reported a lower average value, 0.7 particles per m3
(range 0-7.5 particles per m3). Water samples (218-561 litres) have also been taken in the water
column of HAUSGARTEN (near surface, ~300 m, ~1000 m, and above the seafloor) with reported
values ranging from 0-1,287 particles per m3 (Tekman et al., 2020). The highest reported values were
seen in subsurface waters. Although in many cases, subsamples were processed for data analysis (5-
100%). Some of the highest values of MP have been reported in coastal water bodies near Ny-
Ålesund, Svalbard (61.2 particles per m3; Granberg et al., 2019).
Surface waters in the eastern Canadian Arctic waters of Nunavut were investigated for MP using
bucket samples, reporting an average concentration of 0.22 ± 0.23 particles per L (Huntington et al.,
2020). The concentrations were not related to the human populations suggesting that MP
contamination in the Canadian Arctic is primarily driven by long-range transport.
Although scarce, data collected throughout the water column can be used to provide an insight into
the three-dimensional distribution of MP in the Arctic (Amélineau et al., 2016; Kanhai et al., 2018;
Tekman et al., 2020; von Friesen et al., 2020). Data collected in offshore waters and within the water
column of the Arctic support the hypothesis that the water column constitutes a major reservoir for
MP in the Arctic (Cózar et al., 2017). During an investigation of two oceanographically different
fjords, Kongsfjord and Rijpfjorden, von Friesen et al., 2020 observed variable microliter
concentrations along the two bathymetric gradients. Highest concentrations were identified in the
subsurface samples from Kongsfjord (48 particles per L).
Studies of MP concentrations (> 100 µm, volume of 1-3 m3) in the water column in Monterey Bay,
California demonstrated the highest levels in water samples collected from depths just below the
mixed layer (15 particles per m3 at 200 m), at a deep site located 25 km from the nearest land.
Microplastics concentrations near the sea surface (5 m) were among the lowest measured (median 2.9
particles per L) and were roughly equivalent to those of the deepest waters sampled (1000 m, median
2.9 particles per L). Concentrations were highest at intermediate depths into the mesopelagic zone
(Choy et al., 2019). It must be noted that the density of polymers along with biotic and abiotic factors
can alter a particle’s buoyancy and this will influence the position location of plastics within the water
column. There is evidence of items made of low-density polymers in the deep sea as well as high-
density polymers floating on the ocean surface. In general, density is not a relevant property to
explain vertical position or displacement of plastic. This is especially true for macrodebris. The
presence of air bubbles or of certain shapes do not allow sinking. Polymer density may be relevant for
MP or nanoplastics, but at these scales turbulence and surface tension may also be important.
Sources of plastics to the Arctic may include long-range transport from distant sources, or input from
local sources such as urban centres (Rist et al., 2020), fishing, wastewater treatment facilities
(Granberg et al., 2019; von Friesen et al., 2020), and melting of sea ice (i.e., released during; von
Friesen et al., 2020).
At the time of writing, there has only been a single investigation of a small freshwater lake. Sediments
adhered to rocks from a shallow lake (0.75m) near Ny-Ålesund and were investigated for
anthropogenic particles. Microplastics were estimated to equate to 90 particles per m2 (González-
Pleiter et al., 2020).
AMAP Litter and Microplastics Monitoring Guidelines
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No other investigations of freshwater bodies or rivers in the Arctic have been published. Although
they are of interest due to the high volumes of riverine discharge into the Arctic regions from Russian
and Canadian rivers.
2.2.3 Trends to date
Unfortunately, the investigations to date in the Arctic are difficult to compare because they use
different methods, different reporting criteria, and different measurement values. Thus, there is
currently no available data on the scientific trends.
Monitoring ideally should focus on identifying trends in sources to ensure that mitigation strategies
and remediation efforts can be introduced close to source or accumulation areas, respectively. For
trends to be monitored effectively in the Arctic, the differences between summer and winter seasons
need to be considered as does the repeatability of sampling. For example, sampling in the Arctic can
be costly and needs to be planned carefully (especially those efforts that require research vessels).
Further, the winter season enforces its own limitations, ice-covered water cannot be sampled to
produce informative or representative data. Without careful consideration, this may lead to gaps in
information. The methods used should be harmonized throughout the AMAP regions.
Table 2.3 Summary of available data in the Arctic.
Freshwater
Marine
Sources
Limited data
Limited data
Inshore
Limited data
Limited data
Offshore
-
Data available
2.2.4 Benefits of using water samples
In terms of macroplastics, visual observations of floating macroplastics can be conducted in parallel to
bird and mammal surveys at no extra cost. Data gathered can help provide information on sources and
potential interactions with biota. Microplastic sampling can be conducted using surface sampling nets
or pumps, which are already used and recommended around the world, thus enabling the development
of comparable datasets. Pump sampling can be conducted through seawater intakes on research
vessels where a large amount of metadata is usually collected for characterizing the water column,
allowing metadata to be directly compared to sampled MP. This can be important when sampling in
areas where water stratification changes. Furthermore, many research vessels are already involved in
long-term dataset collections, such as nutrients, therefore MP could be added to these routine
sampling regimes using pump methods or towing a Ferrybox so as not to disrupt ongoing programs.
The water column can be monitored to infer the vertical distribution of plastics. However,
differentiating between those sinking or returning to the ocean surface is not possible at present.
Limitations of water sampling
Meteorological conditions are often a limiting factor for water sampling or monitoring efforts. Surface
water monitoring is reliant on calm weather conditions. Visual surveys require good visibility. Surface
sampling nets require stable surface conditions and can be severely hampered by large plankton
AMAP Litter and Microplastics Monitoring Guidelines
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blooms. Microplastic sampling using nets can also introduce sources of error from self-contamination,
including sampler’s clothing (microfibers) and sampling platform (i.e., but also from the research
vessel, small boat, or other). All sampling of offshore waters requires access to research vessels,
whereas coastal water and inland water sampling can probably rely on smaller, more easily accessible
sampling platforms, although then, the equipment used needs to be similar. Coastal sampling can be
hampered by changes in tidal directions.
2.2.5 Methods
Sample collection
Surface waters:
Surface water samples can be collected using different gear including nets and pumps to investigate
MP. Several standards and recommended protocols have recently emerged for sampling MP. Table
2.4 summarizes the recommended protocols for each sample type. For example, a manta net can be
deployed from a research vessel for a period of 10-30 minutes, with a speed of between 1 to 3 knots.
After each tow, nets must be washed and rinsed onboard with properly filtered water from the outside
using the deck hose, and the cod-end sampler should be removed and rinsed in contamination-
controlled conditions. Samples are washed using filtered seawater and a series of clean metal sieves
(e.g., 5 mm and 200 µm) to fractionate samples before subsequent analysis. Manta nets have limited
use in rough seas; waves affect manta results and differences between GPS and flow meter data can
occur as has been seen in the Arctic (Lusher et al., 2015) and through dedicated comparative studies
(Michida et al., 2019). Wind speed may also affect the vertical displacement of particles in the upper
layers of the water column (Kukulka et al., 2012) and wind stress and particle concentration were
negatively correlated, with high densities being found at relatively low wind speeds. When correcting
the abundance of particles > 700 μm for the effect of wind-induced mixing, Suaria et al., 2016 found a
correction coefficient of 2.06 (max 8.97), resulting in an increased average concentration of
particles/m2 after correction. CTD rosettes can be deployed at the surface, and, providing all bottles
are fired together, they can collect a volume of water that may be comparable to net samples. CTD
bottles used in parallel with bucket sampling may provide a useful tool to sample microfibers in the
surface and subsurface waters (Ryan et al., 2019).
Different count protocols for quantification of floating macrolitter have been proposed by Aliani et
al., 2003; Ryan, 2013 modified in Ryan, 2014; Suaria and Aliani, 2014; and Strafella et al., 2019. The
EU Joint Research Centre in Ispra organized a workshop in Barcelona in 2016 to define a standard for
the sighting of microdebris. The identified methods were subsequently used in parallel during a
common expedition in the Southern Ocean (Suaria et al., 2020a). The resulting recommendations
were as follows: all floating debris items should be counted and recorded with a time assignment
during daylight hours. Position data should be obtained through the vessel log. Metadata surrounding
the items to be recorded include: size (estimated to the nearest 1 cm), perpendicular distance from the
ship (m), buoyancy (at, above, or below the water surface), type of material (plastic, metal, glass,
worked wood, paper-card, etc.), function (fishing gear, packaging, etc.), and color. Items can be
further assigned to size categories (A. 2.5-5 cm, B. 5-10 cm, C.10-20 cm, D. 20-30 cm, E. 30-50 cm,
F. > 50 cm) and to one of two major type categories: anthropogenic marine litter (AML) and natural
marine litter (NML; Campanale et al., 2019; Suaria and Aliani, 2014). Data collection by this method
is relatively simple and can be carried out from ships of opportunity as well as volunteers and in
citizen science projects, following training. Training is a very critical step toward data quality when
AMAP Litter and Microplastics Monitoring Guidelines
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citizen science is used, but it is also relevant in field work activities carried out by scientists with
limited experience in plastic sampling.
Subsurface and water column:
Sampling MP in the water column can be approached using vessels of opportunity or through targeted
efforts. High volume pump samples have been shown to be very beneficial to collect large volume
samples, and supplementary data can be collected simultaneously for comparison of results (see
Lusher et al., 2015; Tekman et al., 2020). CTD rosettes can be used to collect water samples, but they
may not be able to get large volumes. The volume of water required will be dependent on the presence
of anthropogenic and organic items per sample. In the Arctic, a sample of 1 m3 appeared to be
sufficient when working with the underway pump systems (Lusher et al., 2015; Kanhai et al., 2018).
Vertical nets (WP2) and bongo nets used for sampling zooplankton from the water column also have
the possibilities to record MP: from 200 meters and up with a tow speed of 0.5 m/s, mesh size of 180
µm, and opening area of 0.25 m2, sampled volume of 50 m3.
Monitoring macrolitter in the water column is technically feasible, but not recommended in present
day regular monitoring programs.
Table 2.4 Recommendations from international groups as well as an example of how such methods
could be implemented in ongoing annual surveys in the Barents Sea.
Guideline (level)
Example:
GESAMP 2019
(UN)
Ministry of
Environment Japan,
Michida et al., 2019
(G20)
BASEMAN 2019
(JPI Oceans
project)
Norwegian-Russian
ecosystem survey in
the Barents Sea
Manta
- Tow duration
- Mesh size
Recommended
20 mins,1-3 knots
0.3 mm
20 mins, 3 knots
15 mins, 3 knots
0.35 mm
Bulk water sample
- Seawater intake
- In situ pump
Feasible
N/A
N/A
Feasible
Niskin bottle
(CTD rosette)
N/A
N/A
Vacuum filter
directly onto GF
paper
Possible dependent
on volume
FerryBox
N/A
N/A
N/A
N/A
Visual survey
Recommended
N/A
N/A
Between stations,
distance 35 nm
Vertical plankton
nets (WP2)
N/A
N/A
N/A
Stations Fig 2.1
AMAP Litter and Microplastics Monitoring Guidelines
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Sample processing
For methods related to sample processing, please refer to GESAMP, 2019 and Michida et al., 2019 for
recommendations. Samples containing high levels of organic matter will need further processing
before they can be analyzed for MP. Methods include digestion using bases or enzymes (acids are not
recommended) and density separation. High temperatures and strong reagents are discouraged
because they can affect plastic particles (Hurley et al., 2018; Lusher et al., 2020). Method choice is
usually laboratory dependent. Any method used should be validated before use on samples to test
spiked samples. Limitations of the methods must be reported to allow researchers to see the deviations
from methods clearly.
Specific to the Arctic
There are currently no specific protocols available for the Arctic, although the relevant monitoring
protocols for manta nets and pump samples are published in Lusher et al., 2015; Cózar et al., 2017;
and Kanhai et al., 2018.
2.2.6 Quality assessment/quality control (QA/QC) specific to the compartment/matrix
For all investigations of MP in water samples, all sampling devices must be thoroughly cleaned before
sampling, i.e., flushing with high volumes of filtered or ultra-pure water. Potential sources of
contamination must be collected to act as a reference, including the clothing worn by samplers and
any plastics used in the vicinity on the vessels, as well as vessel paint. Importantly, field blanks must
always be collected. A field blank can include a filtered water rinse of a net (Michida et al., 2019) or
an open moist (filtered water) sample container/petri dish for the same duration as handling of sample.
Participation in workshops and ring tests to assure quality assurance/quality control (QA/QC), for
example, through QUASIMEME is encouraged.
It must be noted that there is a great need to implement chemical characterization of fibers identified
in surface waters. In a recent investigation of a global dataset of seawater samples, the majority of
fibers were cellulosic (79.5%) or of natural origin (12.3%) whereas only 8.2% were synthetic (Suaria
et al., 2020b).
An overview of QA/QC measures of MP sampling has been presented in Brander et al. (2020).
2.2.7 Existing monitoring for populations/contaminants in the Arctic
There are no current existing monitoring programs in the Arctic relevant to plastics in water samples.
However, there have been several sporadic scientific investigations. The joint Norwegian-Russian
ecosystem survey in the Barents Sea performed annually in August-October includes sampling of
several fish species, shrimp, and sediments for the monitoring of contaminants. Floating debris and
macrolitter as bycatch in trawls are recorded. Microplastics are collected from manta trawls from
some of the stations (Figure 2.1).
AMAP Litter and Microplastics Monitoring Guidelines
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Figure 2.1 The joint Norwegian-Russian ecosystem survey in the Barents Sea performed annually in
August-October includes approx. 300 stations.
2.2.8 Recommendations
In Table 2.5 below, the recommendations for monitoring and research are highlighted. It must be
noted that to determine the frequency of sampling in terms of replicates per given sampling period, an
assessment must be carried out in each region independently. For example, the sampling conditions as
well as local conditions will dramatically affect the duration required for each sample. A power
analysis should be carried out (with a minimum of 12 samples) per location to assess the variable
plastic concentrations in a particular region. To this end, at the current level of data, it is not possible
to determine the number of replicates or the number of stations required. This should become a
priority for individual regions and should include an assessment by independent researchers who have
no conflict of interest in the number of samples required.
In terms of frequency of surveys, it is recommended that sampling be carried out at a minimum on a
yearly basis similar to the environmental monitoring for environmental contaminants. More intense
sampling can be carried out if the aim is to assess seasonal variation, and to that end, sampling once
per month, or once per quarter could be suitable.
Because net sampling is already commonplace and can provide harmonized data, it is recommended
to continue this process while other methods are further validated. It is understood that this will focus
on larger particles *300 µm and in so doing underrepresent the smaller-sized faction that are of
interest in terms of understanding the impact or potential uptake by marine biota. Until further
AMAP Litter and Microplastics Monitoring Guidelines
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methods are explored, this is the method with the highest technological readiness level and it is
already operational.
The volume of samples taken per sample will be heavily dependent on the sampling conditions during
a particular survey; to account for this, the reporting of metadata is of upmost importance. Sampling
can then be normalized for wave and windspeed. Thus, providing countries follow the same reporting
system, data can be comparable.
Status of understanding for a representative sample:
Number of samples: requires further testing of statistical power.
Number of replicates: requires further testing of statistical power.
Number of field blanks: should be carried out in parallel to samples; ideally one field blank should be
carried out in parallel to each collected sample. One method for field blanks is presented in Michida et
al., 2019: here the net is cleaned thoroughly from the outside before the start of the sampling run to
ensure no particles remain. The rinse water can be observed for particles. A second method is the
exposure of dampened filter paper to the air while sampling is performed. This should give an
indication of the number of airborne particles.
Table 2.5 Summary of monitoring and research recommendations for water samples.
1st level (must do)
2nd level (should do)
Monitoring
Net samples (water surface of coastal,
freshwater, and fjord; 300 µm mesh)
(Volume will be variable and
dependent on sampling conditions)
Large pump - selected offshore
locations (sequential filtration, e.g., 1
mm, 300 µm, 100µm) collected
subsurface 1-7 meters, 1 m³ per
sample
Large volume pump samples volume
(sequential filtration, e.g., 1 mm, 300
µm, 100 µm)
Subsurface 1-7 meters, 1 m³ per
sample
Research
Offshore net samples
Visual surveys
Large pump - inshore, 1 m³ per sample
from surface waters
Visual surveys supported by
communities including opportunistic
observations from marine mammal
observers, fisheries observers, and
fishers
AMAP Litter and Microplastics Monitoring Guidelines
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Table 2.6 Summary rationale for recommendations, including estimated costs for implementing
programs; 0 litter and plastic pollution monitoring already in place with regular funding; $ -
relatively inexpensive because new litter and microplastic monitoring programs can use existing
programs to obtain samples in at least some regions, but need to have some additional capacity to
process samples for litter and plastic pollution; $$ - either sampling networks and/or capacity need to
be developed to monitor litter and microplastic pollution; $$$ - development of sampling networks,
processing capacity of samples, and reporting all need to be developed in the majority of the Arctic
regions.
Recommendation
Program Cost
Rationale
Primary Recommendations
Coastal: Net sampling ≥ 300
µm
- Routine monitoring
surveys can be adapted
- Easier to adapt to
weather conditions in
coastal areas
$
Existing research programs are already in place
conducting routine surveys making it relatively
easy to add a collection for plastic pollution to
the workplan. Minimal costs would need to be
added to implement plastic pollution monitoring
to cover the costs of sampling. Processing will
require additional costs.
Offshore: pump samples
- Routine monitoring
surveys can be adapted
- Less challenging to use
pumps in offshore waters
$
Existing research programs are already in place
conducting routine surveys making it relatively
easy to add a collection for plastic pollution to
the workplan. Minimal costs would need to be
added to implement plastic pollution monitoring
to cover the costs of sampling. Processing will
require additional costs.
Secondary Recommendations
Inshore: pump samples
- Routine monitoring
surveys can be adapted
$$
Existing research programs are already in place
conducting routine surveys making it relatively
easy to add a collection for plastic pollution to
the workplan. Minimal costs would need to be
added to implement plastic pollution monitoring
to cover the costs of sampling. Processing will
require additional costs and sequential filtering is
more time consuming.
Subsurface sampling
- Routine monitoring
surveys can be adapted
$
Existing research programs are already in place
conducting routine surveys making it relatively
easy to add a collection for plastic pollution to
the workplan. Minimal costs would need to be
added to implement plastic pollution monitoring
to cover the costs of sampling. Processing will
require additional costs.
AMAP Litter and Microplastics Monitoring Guidelines
40
2.2.9 Knowledge gaps and research priorities
Box A: data needs/expectation
Must have data
Location
Date
Collection method
Depth
Volume of sample (including original volume and subsampled
volume
and any analysis on variance between subsamples)
Number of particles
Auxiliary environmental data
Polymer type (mandatory for at least a subsample > 300 µm)
Nice to have for all data
Color
Size category (> 1 mm, 1 mm-300 µm, 300-100 µm, < 100 µm)
Morphological information (shape)
Polymer type
Auxiliary data
Wind speed and
direction
Sea state
Depth in case of
seawater from
rosette
Proximity to
coastal, river
streams and/or
estuaries
Proximity to
wastewater
treatment plants
AMAP Litter and Microplastics Monitoring Guidelines
41
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