Sustainable Implementation of Citizen-Based Plastic Monitoring of Fresh Waters in Western Africa

Abstract

Citizen science projects globally have increasingly been implemented in collecting and analysing environmental data. At the same time, these initiatives are often project-based and, therefore, of short duration. This presents a challenge as data from such activities may not be used in research and political decision-making. This research aims to explore the barriers and solutions for establishing a sustainable long-term citizen-based plastic monitoring strategy in fresh waters based on a case study in Accra, Ghana. This case study is particularly relevant due to the significant issue of plastic pollution in the region, limited official monitoring data to effectively address the problem, and the potential role of citizen science in addressing this data gap in the long term. Data on barriers and solutions were collected based on eight expert interviews, a survey amongst 17 stakeholders, and subsequent roundtable discussions with 24 experts and stakeholders from academia, the private sector, the public sector, and civil society. From this, we identified 30 types of barriers and 21 types of solutions to implement citizen science in the long term. These barriers and solutions relate to five fields of action (social, economic, environmental, technical, and management and governance) and four stakeholder groups (public sector, private sector, civil society, and academia) to implement solution pathways for long-term citizen science projects. Based on our findings, we make suggestions as to how citizen science can be implemented more sustainably in the future in different fields of action and from various institutional perspectives. With this, we hope to advance the potential use of citizen science and citizen science data in research and policy design related to plastics in fresh waters.

1. Introduction

1.1. Practical Problem Statement

The pollution of fresh waters such as rivers and lakes with macro- and microplastics is a serious problem, which needs targeted political action [1,2]. In the context of evidence-informed decision-making, such political action needs reliable and harmonised, and therewith comparable, long-term monitoring data on the actual sources and pathways of plastic pollution in fresh waters [3,4,5,6]. However, data on riverine plastic pollution is still lacking and is not always directly comparable on a global scale due to diverse barriers to plastic monitoring, specifically in the global south, such as limited financial, human, and technical resources for monitoring [7,8,9]. This, again, calls for innovative approaches to overcome barriers to plastic monitoring on fresh waters.

Citizen science can potentially play an important role in overcoming this data lack for informed policy decisions. In the field of plastics, in particular, the utilisation of citizen science has increasingly emerged as a valuable method [10,11,12,13,14]. Also, there are already examples of citizen science projects in the field of plastic monitoring both in the Global North and in the Global South supporting data collection [15,16,17,18,19,20,21]. This development in the field of plastic monitoring represents well the general assumptions on the role of citizen science in the monitoring of freshwater quality which is in line with Sustainable Development Goal 6 on Water [22,23,24,25]. This development also represents overarching discussions on the potential positive role of citizen science in advancing the achievement of sustainable development goals across policy issues and regions [26,27].

However, citizen science projects often have a fixed duration, reducing their potential for sustainable data collection and, thus, also for policy action against plastic pollution. In terms of space, there still exist significant gaps in the global representation of citizen science activities with respect to plastic monitoring in fresh waters and water quality more generally [28,29]. As studies in the Global North dominate citizen science plastic monitoring projects by 66%, representation from low-income countries, particularly in the Global South, still remains limited [30]. In relation to time, citizen science activities are often of short duration which questions their sustainable long-term data contribution as a prerequisite for evidence-informed decision-making [25,29].

1.2. Research Problem Statement

Research has identified potential barriers to a sustainable implementation of citizen science, particularly in the field of environmental and plastic pollution. Barriers are generally defined as hindrances to the environmental monitoring and the monitoring of micro- and macroplastics, in particular [9]. In our context, barriers refer to hindrances to the monitoring of micro- and macroplastics based on a citizen science approach. These barriers provide first insights into the limitations of regional and temporal representation, making it challenging to achieve long-term success. The identified barriers span a wide range of issues that affect project cycles from planning stages through to active citizen involvement and data validation. The first set of barriers refers to a lack of resources, including human resources and financial resources. A lack of personnel to plan and implement time-intensive citizen science projects is key. This issue has been observed across general citizen science projects and ecological programs [31,32] and can hinder data validation and quality control which is particularly crucial for the relevance of citizen science data for research and policy action [32,33]. Limited financial resources hinder expenses for equipment and technical resources as well as incentives for participation in citizen science projects [32,34]. Furthermore, a number of social factors are mentioned. First, a lack of motivation and distrust in the project’s efficacy has been mentioned [31,32,34]. Another social barrier is low scientific literacy, particularly among those with a lower formal education or without a scientific background. Furthermore, language barriers can pose significant challenges in some regions [28,32]. There is in part also limited knowledge of citizen science opportunities, inadequate organisational capabilities like planning and leadership, and a general lack of institutional interest [28]. In part, there are also physical limitations that can hinder participation in ecological programs [34]. Some projects face additional hurdles such as developing strategic initiatives and effectively translating data into valuable outcomes for natural resource management [33].

However, while knowledge of potential barriers to the implementation of citizen science projects exists, a systematic analysis of barriers to long-term implementation in citizen science, especially in the field of plastic monitoring in Western Africa, is still missing. Also, research hardly links in-depth analyses of barriers with potential solutions and solution pathways considering different fields of action and actors in the political-administrative system, businesses, civil society, and academia.

1.3. Research Goals

Against this background, this study aims to identify and classify existing barriers and solutions (pathways) to sustainable citizen-based plastic monitoring in fresh water in Western Africa. This, again, serves as a more sustainable implementation of citizen science in the field of plastic monitoring, as one important pathway to overcome monitoring deficits in the field of plastics in fresh waters and water quality, more generally. Citizen science is here understood narrowly in terms of contributory citizen science, as ‘the collection and analysis of data relating to the natural world by members of the general public’ [35]. Sustainable monitoring is here understood as monitoring activities that go beyond short-term activities and projects and aim at a continuous collection and analysis of data for a better understanding of systems and respective policy interventions. Barriers and solutions, however, are understood broadly and can encompass different dimensions such as management and governance issues which go beyond actual project resources such as personal and human resources. This is key as it broadens the discussion from actual project contexts to the underlying causes of barriers and solutions for a long-term citizen-based monitoring strategy.

1.4. Case Study Approach

In order to address our research aim, this study provides a case study in Accra, Ghana. In Ghana, the rapid economic growth coupled with inadequate waste management practices has led to an accumulation of plastic waste with an increasing leakage of plastics into the ocean [36]. This situation poses serious concerns for freshwater ecosystems, affecting both environmental health and socio-economic aspects such as flood risks and marine fisheries [37,38]. As a partner of the Global Plastic Action Partnership [39], Ghana is effectively seeking solutions to mitigate plastic waste pollution. However, data gaps regarding the occurrence of plastic waste in freshwater systems still remain and continual data for targeted political action is needed [5,37]. To address this issue effectively, citizen science and clean-up activities have increasingly been implemented to increase data availability and action. At the local level, Ghana hosts a growing citizen science community of different ages engaged in monitoring plastic debris on beaches, such as the projects COLLECT, Plastic Punch, and the Smart Nature Freaks Youth Volunteers Foundation (SNFYVF), among others [38,40,41,42]. Yet, it is still unclear how citizen science can be implemented in the long term to overcome known barriers to plastic monitoring in fresh water systems and transporting plastics into the ocean [9]. Based on expert interviews, a survey amongst stakeholders, and further workshop discussions, this study addresses this research lack from multiple perspectives. In that sense, the results of this case study serve as a representation of many cases of severe plastic pollution in Western Africa, which considers citizen science as an approach to the sustainable monitoring of plastics in fresh waters as a means for targeted policy action.

1.5. Outline

After this introductory Section 1, Section 2 introduces the case of plastic monitoring in Ghana, as well as the mixed-methods approach to data collection on barriers and solutions including expert interviews, a survey, and discussions at a stakeholder workshop. Section 3 presents the results of the identified barriers and solutions as well as solution pathways to a sustainable, long-term implementation of citizen-based plastic monitoring. Section 4 and Section 5 discuss the results and conclude on the role of citizen-based approaches to overcome data lacks for targeted policy measures against plastic pollution.

2. Methods

This section introduces the mixed methods approach to collect and analyse data on barriers, solutions, and pathways to the sustainable implementation of citizen-based plastic monitoring. This includes a three-step approach, including interviews with national and international experts, a survey amongst stakeholders, and roundtable discussions with the same stakeholders from academia, civil society, businesses, and the public sector participating in a workshop that took place from 11 to 12 September 2022 in Accra, Ghana and which aimed at advancing community-based plastic monitoring in this region.

2.1. Expert Interviews

As a first step of data collection and analysis, we conducted interviews with eight national and international experts on citizen-based plastic monitoring. The main criterion for the selection of experts was their knowledge in the field of citizen science and plastic monitoring in the region of Accra or in comparable regions. Experts should further relate to various sectors such as academia and civil society to identify barriers and prerequisites for a long-term citizen science-based monitoring strategy. The respective experts were identified based on a literature analysis and through snowballing. A list of the selected experts is available in Supplementary Material Table S1.

The main goal of the expert interviews was to identify key barriers to long-term citizen-based plastic monitoring as well as the potential solutions to overcome these barriers. Accordingly, two types of questions guided these interviews: (i) identification of key barriers to long-term citizen-based monitoring of plastics in fresh waters in Accra (Ghana) and comparable regions and (ii) proposing solutions to overcome these barriers to long-term citizen-based monitoring of plastics in fresh water in Accra (Ghana) and other comparable regions in Africa.

The actual interviews were structured around a questionnaire comprising the following components: a general introduction about the project, the interviewee’s background in citizen science, an exchange on current citizen science activities in Ghana or internationally, a discussion on the existence and need for a long-term citizen-based plastic monitoring strategy, the identification of existing or potential barriers for a long-term citizen science-based monitoring strategy, an exploration of existing or potential solutions to overcome these barriers, a consideration of prerequisites for scaling up citizen science activities to other cities comparable to Accra, and closing remarks (see the guiding questionnaire in Supplementary Material Table S2).

Questions were generally open to allow for the identification of a wide set of barriers and solutions. Further, more specific questions were added in case interviewees struggled with answering the open questions. In terms of barriers, for instance, interviewees were generally asked “What are barriers to a successful design and implementation of a long-term citizen science-based monitoring strategy?” Follow-up questions hinted at specific barriers such as a lack of interest, knowledge, resources, and others.

The interview dates were between 1 July 2023 and 6 September 2023. Interviews took place online via the Zoom platform and lasted 60 min, on average. In order to facilitate the analysis of the interviews, all interviews were recorded on the Zoom platform after consent by all interviewees.

These interviews were transcribed automatically using SONIX transcription software [43]. The transcripts were further analysed using MAXQDA software [44]. The analysis included several steps. The first step was general coding and aimed at identifying text segments mentioning the barriers and solutions to long-term citizen-based plastic monitoring in freshwater environments. In the second step, a more detailed coding categorised text segments related to barriers and solutions into five domains: social, economic, environmental, scientific and technical, and management and governance (see also [45]). Lastly, a cross-checking of the coding was conducted by two researchers to ensure consistency and reliability in the coding process.

2.2. Stakeholder Survey

As the second step of data collection, a survey amongst stakeholders from academia, civil society, businesses, and the public sector with connections to the field of plastic monitoring in Accra was conducted. The survey generally aimed at understanding citizens’ awareness, knowledge, and further engagement in addressing the issue of plastic pollution. The actual survey included several categories (see Supplementary Material Table S3), of which the following two aspects are presented in this study:

• Basic information on survey respondents (sector, gender, and level of expertise). The questions were closed and answers could be selected from a predefined set of answers.
• Questions related to awareness, including barriers to citizen-based plastic monitoring in Accra and solutions strategies to overcome these barriers. The questions on barriers and solutions were open, providing the participants the opportunity to share the three most important barriers and solutions.

Data was collected based on SoSci, a professional social science survey tool for online surveys [46]. The tool is in line with European data protection regulations, thus building trust amongst respondents as a prerequisite to sharing data with the authors. The tool is open-sourced for educational institutions and for research purposes.

The survey was circulated amongst the participants of the workshop on community-driven plastic monitoring in Accra (n = 26) one week prior to the workshop and was open for one week. In total, 18 participants responded to the survey, of which only 17 responded to the content-related questions. The survey respondents represent different expert categories, amongst them academia (10 answers, 55.6%), civil society (4 answers, 22.2%), the public sector (3 answers, 16.7%), and the private sector (1 answer, 5.6%). In terms of gender, two-thirds of the respondents were male (12 answers, 66.7%) and one-third of the respondents were female (6 answers, 33.3%). The respondent’s experience related to plastic monitoring varied, from no experience (8 cases, 44.4%) to experience of up to 3 years (7 cases, 38.9%), 4 to 6 years (2 cases, 11.1%), and more than 7 years (1 case, 5.6%) (see Figure 1).

Answers to open questions were again categorised along specific types of barriers and solutions related to the social, economic, environmental, science and technology, and management and governance domains.

2.3. Roundtable Discussion

In a third step of data collection, the role of barriers and solution strategies were discussed at the workshop on community-driven plastic monitoring in fresh waters (see introduction to Section 1). The workshop focused on understanding how citizen science could be effectively implemented in the long term in Accra (Ghana). The workshop discussions were designed as a role play and aimed (i) at identifying prioritised barriers to the long-term implementation of citizen-based plastic monitoring from various institutional perspectives, (ii) at proposing key solution strategies to overcome these barriers, and (iii) at determining potential pathways for implementing these solutions, considering diverse institutional viewpoints.

In order to identify barriers, solutions, and solution pathways from various institutional perspectives, we followed a two-step approach. As a first step, the workshop discussions were introduced in a presentation explaining the challenge of long-term citizen-based plastic monitoring and the results of potential barriers and solutions strategies as identified from the expert interviews and the online survey from the workshop participants. In the second step, working group discussions took place in which the workshop participants were asked to prioritise barriers and solution strategies to long-term citizen science plastic monitoring from various institutional perspectives and to define potential solution pathways. Four institutional perspectives have been included: academia, civil society, government and public authorities, and business and industry. To facilitate this process, participants were provided with two lists of barriers and solutions and a worksheet. The respective working groups have been facilitated by one of the project members. The results have been reported back to all workshop participants in a general reporting back session.

For the analysis, the worksheets of the working groups were photographed. In addition, detailed notes of the reporting back sessions were taken. The photographs and notes served as a basis to summarise the prioritised barriers, solutions, and solution pathways from different institutional perspectives.

2.4. Synthesis of Results

The results of the three analyses have been synthesised as follows: The results on barriers and solutions based on the expert interviews and the survey have been summarised along 5 categories of barriers and solutions, including social, management and governance, economic, technical, and environmental barriers and solutions (see Section 3.1). The workshop discussions were based on these results to facilitate the comparison of barriers and solutions from different institutional perspectives along the 5 categories.

3. Results

3.1. Barriers and Solutions to Citizen-Based Plastic Monitoring

3.1.1. Overview of Barriers and Solutions

This section provides an overview of the identified barriers and potential solutions based on data collected from both expert interviews and the survey. A detailed overview of the results by the respective method is provided in the Supplementary Material Tables S4–S7. In total, the interviewees and survey respondents mentioned 73 barriers and 102 solutions. Due to overlaps in their answers, the barriers and solutions were further classified into 30 types of barriers and 21 types of solution strategies to overcome them. These barriers and solutions have been assigned to different fields of action, namely the social, economic, environmental, technical, and management and governance action (Figure 2,

Table 1. Specific types of barriers and solutions to citizen-based plastic monitoring.

Categories	Types of Barriers	Types of Solutions
Social	− Lack of awareness and knowledge gaps about the environmental impacts of plastic − Lack of commitment − Lack of education − Little focus on community structures and ethical aspects from the project lead’s side − Language barrier − Lack of expertise − Lack of capacity building − Limited accessibility to science − Extreme poverty − Vandalism to monitoring sites − Jealousies in communities − Conflicting interests amongst project team members or different stakeholders	− Methods and tools of communication and sharing information with citizens (e.g., social media, television) − Education − Incorporating diverse stakeholders in project design − Involvement and joint monitoring and evaluation with citizens to enhance trust- and capacity-building − Offering training for citizens on how to monitor and collect data − Sensitising households and communities − Using local language − Medical provision
Management and Governance	− Poor waste disposal management − Lack of policies to guide and enforce plastic pollution prevention − Reluctance of policymakers to incorporate the community´s contribution into decision-making processes and policies and a lack of evidence-informed policy design − Time restrictions of citizen science projects − Unclear development of citizen science strategies − Need for permission to enter monitoring sites or communities	− Incorporation of a wide range of actors into citizen science projects (e.g., civil society, academia, public sector, international bodies, private sector, and funding bodies) − Forming new entities for project organisation (e.g., regulatory body, collective from different bodies, and independent mediators) − Policy design for plastic regulation and management − Separation of responsibilities in projects − Horizontal coordination between ministries − Sustainable long-term project planning
Technical	− Lack of platforms for storage, management, and transfer of citizen-based data − Lack of international standard protocols and websites − Poor harmonisation of data − Lack of technical resources − Lack of technical personnel and know-how − Sampling errors − Limited plastic transport data	− Accessibility to technical tools and apps − Creating a comprehensive knowledge platform − Robust monitoring protocols for data collection − Technical personnel − Establishing a data management system
Economic	− Lack of sustainable funding for citizen science activities (e.g., for upscaling, outreach, and science communication) − Limited financing for incentivising participants (e.g., for transport to the monitoring locations) − Limited availability of tools and resources for monitoring (e.g., smartphones and internet connectivity)	− Incentivising participants through reimbursements of costs − Alternative funds for citizen science projects, e.g., private sector, international donors, and government
Environment	− Contaminated plastic − Hindrance to access monitoring sites (e.g., riverbanks might be unsafe to monitor on)	− N.A.

).

3.1.2. Specific Barriers to Citizen-Based Plastic Monitoring

The social category revealed 12 barriers. The most frequently identified social barriers are related to the lack of awareness and knowledge among citizens regarding the environmental impact of plastics and the importance of monitoring these impacts. These awareness and knowledge deficits can hinder them from participating in citizen science activities. Another barrier is the lack of education and the absence of effective education campaigns. From the project lead´s perspective, insufficient efforts in trust-building with participants due to the typically short-term nature of citizen science activities, an inadequate understanding of community structures, and neglecting ethical aspects can impede the successful implementation of citizen science projects. Furthermore, language barriers can hinder projects from engaging participants and effectively monitoring plastic pollution on a large scale. Effective communication, in fact, often requires proficiency in the local language when engaging with communities since translation from English into the local language is not always possible or a wrong translation could lead to misunderstandings. Additionally, other social barriers include a lack of expertise, a lack of capacity building, limited accessibility to science as well as the existence of extreme poverty, which can result in a lack of interest in citizens to engage in monitoring activities. Vandalism of monitoring sites is another barrier taking place in the course of citizen science projects. Moreover, jealousy can arise within communities when only a few individuals are employed and earn money from the project while others are not. Social barriers might also occur after the implementation of citizen science projects. Here, conflicting interests and intentions amongst project team members, e.g., amongst natural and social scientists and different stakeholders can hinder project dynamics.

In the management and governance category, six types of barriers were mentioned referring to overarching framework conditions as well as project-related aspects. Management and governance barriers primarily refer to poor waste disposal management and a lack of clear policies on pollution prevention which may become an issue if the sampled plastic cannot be disposed of reliably. Another barrier is the reluctance of policymakers to recognise and integrate the contributions of communities into decision-making processes and policy design, hinting at the barrier of limited citizen science-related evidence-informed policy design within the existing governance structures. Other barriers include the time constraints associated with short-term citizen science projects, the absence of a clear strategy resulting in uncertain developments of citizen science projects, and the necessity for permissions to access monitoring sites.

In the technical category, seven types of barriers were discussed. Technical barriers mostly refer to the absence of platforms and websites for the storage and management of citizen-generated data and for transferring data to the relevant authorities, as well as a lack of international protocols to monitor data. Due to insufficiency in managing collected data, another barrier is the poor harmonisation of that data as a prerequisite for data dissemination to the relevant authorities. Other barriers include a shortage of essential technical resources such as tools and equipment required for effective monitoring, a lack of technical personnel with the necessary know-how to support the monitoring process, as well as sampling errors, and a deficiency of data on plastic transport.

The economic category revealed three types of barriers. The most frequently mentioned barrier is related to the funding of citizen science activities. Funding bodies or municipalities often provide insufficient financial support to citizen science projects on aspects like upscaling efforts, outreach, and science communication due to a lack of understanding or value ascribed by the respective institutions. This limitation extends to another barrier which is the support available for citizens participating in the projects in the form of incentives, e.g., by refunding transportation costs to monitoring locations or providing refreshments in the form of food and drinks. Another barrier is the limited availability of financial resources to effectively participate in citizen science activities. Participants may lack the finances to secure the necessary tools and equipment such as smartphones, internet connectivity, data collection tools, and transportation. A lack of resources can also lead to reduced motivation among citizens to engage in citizen science initiatives.

In the environmental category, two types of barriers were mentioned. The interviewees highlighted potential risks of contact with contaminated plastics, as some plastics may contain toxic substances which were, however, not specified further. Additionally, the accessibility of monitoring sites can be a hindrance, as traversing field sites or riverbanks can be unsafe. For example, if entering areas where illegal mining takes place, verbal or physical attacks might become a risk.

3.1.3. Specific Solutions to Citizen-Based Plastic Monitoring

In terms of solutions, the analysis has revealed eight types of solutions in the social category. The predominant solution refers to enhancing communication and information sharing regarding science and environmental issues. This involves implementing methods and tools of communication such as social media campaigns, storytelling, television, illustrations, and education through educational programs aimed at raising citizens’ awareness and supporting their engagement in citizen science activities. Incorporating diverse stakeholders, such as scientists, community representatives, and policymakers into the project design can help streamline the course of the project. The solution of involving citizens throughout the project and jointly evaluating the results and implications of monitoring activities can enhance capacity- and trust-building. Another solution refers to providing training to citizens on data collection methods and monitoring processes. Additional solutions refer to the importance of sensitising households and communities, using local or community languages, and providing medical support for field activities.

Six types of solutions refer to the management and governance category. The most frequently mentioned solution is the involvement and incorporation of a wide range of actors in citizen science initiatives. These actors include (1) civil society (e.g., individual citizens, communities, teachers, and NGOs), (2) academia (universities and research institutions), (3) the public sector (local government and ministries of environment and/or education), (4) international bodies (such as the World Bank, UN, and citizen science associations), (5) the private sector (companies and foundations), and (6) funding bodies and authorities. Moreover, solutions referred to the formation of entities to be incorporated into the course of the projects. These can be (1) regulatory bodies to organise citizen science projects, ensuring they are long term, and to bring together diverse citizen science organisations, (2) a collective of diverse bodies from different sectors, and (3) a coordination body of independent mediators at a national scale to improve communication and management between different institutions and actors involved in citizen science. Furthermore, solutions for policy design were mentioned on different scales. Those scales comprise designing evidence-informed policies based on citizen science findings, establishing policies to reduce, reuse, and recycle plastic, and the formulation of national policies for plastic regulation and management. Other solutions include clearly defining and separating responsibilities between project activities and finances, horizontal coordination amongst different ministries/departments, and ensuring sustainable projects for 5–10 years in order to guarantee community building and ongoing engagement in monitoring.

In the technical category, five types of solutions were reported. The most frequently mentioned technical solution focuses on ensuring technology accessibility such as monitoring tools and apps to citizens with limited financial resources. Other types of solutions encompass creating a comprehensive knowledge platform that represents all affected stakeholders. Additionally, a robust monitoring protocol ensures consistent data collection. The allocation of technical personnel is another important solution as technical assistance can improve data availability and quality throughout the project. Establishing a suitable data management system falls under a technical solution as well, which is crucial for transparent data processing and reporting throughout the project.

Two types of solutions were mentioned in the economic category. Economic solutions primarily focus on incentivising participants in citizen science activities through refreshments or cost reimbursements for transportation and other forms of effort. Another solution includes the provision of funds for citizen science projects by multiple donors. These donors can come from the private sector, e.g., by raising taxes on businesses that strongly affect water quality (following the polluter pays principle), from international governmental donors, such as the World Bank, as well as from national development agencies or from individuals and the government.

Finally, no solutions related to the environmental category were mentioned.

3.2. Barriers, Solutions, and Solution Pathways from Different Institutional Perspectives

The identified barriers and solutions have further been prioritised by workshop participants. The prioritisation task was designed as a role play, asking participants to prioritise respective barriers and solutions from different institutional perspectives: the academic sector, the public sector, business and industry, and the civil society sector.

Across all actor groups, a total of 27 barriers and 21 solutions were discussed. The barriers and solutions identified in the four sector groups predominantly relate to social aspects. However, there are also some variations depending on the institutional perspective. Results are described below and visualised in Figure 3. More detailed results can be found in Supplementary Material Table S8.

The participants in the group ‘Academia’ discussed a total of seven barriers and seven potential solutions and related solution pathways. Three of the discussed barriers encompass social aspects such as language barriers, limited accessibility to science, and conflicting interests between different stakeholders. Additionally, the lack of sustainable funding for citizen science projects lacking short-term benefits was identified as an important economic barrier. One technical barrier was identified and refers to the lack of technical resources. Further, time restriction was mentioned as a management and governance barrier. To address the language barrier, the ‘Academia’ group proposed the solution to involve local community members who could assist with translations and communicate in the community’s language. A related solution pathway is to gain community entry and meet the chiefs or opinion leaders. Additionally, proper engagement and communication were mentioned as a solution in the social category. The solution pathway to address this issue includes (1) defining project objectives and stakeholders, determining communication needs and resources, and (2) gaining community entry and access to research sites by meeting with chiefs or opinion leaders. A solution pathway to overcome the barrier of limited accessibility to science is to establish a communication concept with relevant stakeholders to support disseminating information. A solution for the issue of conflicting interests involves the participation and involvement of citizens throughout the project and ensuring immediate benefits. Potential solutions for funding include fundraising initiatives from national development agencies or funding alternatives such as livelihood support or incentives. Solution pathways for this issue can be realised through funding from the Ministry of Finance. A solution for the lack of tools is to provide those through the pathway of lobbying at the relevant decision-making bodies by those interested in implementing citizen science. Another solution to address time restriction is sustainable project planning by ensuring long-term ongoing projects.

The group ‘Public Sector’ discussed eight barriers and seven solutions. These barriers relate primarily to the social category and involve issues such as a lack of motivation, lack of trust, vandalism of monitoring sites, and the absence of clear communication channels. Management and governance barriers include the absence of well-defined policy design and challenges in policy implementation, which results in difficulties in conveying complex science concepts to the public and across different institutions. One technical barrier is the low data quality. Furthermore, an economic barrier mentioned involves the lack of sustainable funding. The solutions discussed for the social issues are as follows: (1) engaging citizens in the design of citizen science projects, (2) providing training for citizens, and (3) implementing effective feedback mechanisms and communication, including local dialogue and engagement with media, to inform citizens about the project´s process and outcomes to enhance their motivation and engagement in citizen science initiatives. To address the management and governance issues, the proposed solutions are policy stability and establishing long-term strategies for plastic monitoring and citizen science approaches, more specifically. This can be achieved by a legislative solution pathway by designing policies to safeguard long-term goals. For the technical issue, a suggested solution is to assess the quality of the data before delivering it to the regulatory body. The solution to the economic barrier of low funding is to find suitable funding options. Therefore, solution pathways include strategies such as establishing partnerships with private sector organisations, identifying individual funding opportunities, and creating joint ventures with the private sector.

In the group ‘Business and Industry’, participants identified three barriers and discussed three solutions. The social barriers encompass conflicting interests among stakeholders involved in the project and concerns about vandalism when providing funding. Another issue relates to the management and governance category, specifically business risks and policy challenges. The group discussed solutions for the social issues as follows: fostering collaboration between governmental actors and other stakeholders in co-designing citizen science initiatives to address conflicting interests, with a solution pathway of engaging in lobbying efforts. To address the risk of vandalism, the group proposes promoting community ownership and responsibility for citizen science projects. The solution pathway to support community ownership involves facilitating entry into the community. To mitigate business risk, the proposed solution is proper project planning, with a solution pathway of developing an inclusive communication strategy to ensure proper project planning.

Within the ‘Civil Society’ group, participants identified six barriers and discussed five solutions. The majority of these barriers relate to social issues, including a lack of commitment, conflicting interests, and lack of recognition. Language barriers and religious considerations also fall within this category. Within the management and governance category barriers such as lack of transparency and disengagement due to lack of reliance on short-term benefits were mentioned. Solutions for the social barriers include fostering citizens´ involvement by increasing community involvement and participation, establishing community committees for monitoring and addressing conflicting interests, offering incentives for continual community involvement, and providing more recognition for participants by exploring alternative funding and support mechanisms for communities and institutions (e.g., ministries, local government). To address the language barrier and religious considerations, a solution is to use the local language in communication and training when engaging with the indigenous communities to build trust within these communities. To address the management and governance barrier of lack of transparency, sharing information and trust building with communities was mentioned as a solution. Furthermore, to address the lack of reliance, a solution is to provide tangible benefits. This can be achieved through a solution pathway of exploring alternative funding mechanisms for communities and institutions, e.g., the Ministry for Finance or the local government.

In the ‘management and governance’ group, they recognised barriers such as a lack of transparency, as well as a lack of reliance on short-term benefits leading to disengagement within communities. To address the social barrier of a lack of commitment, the group identified the solutions of fostering citizens’ involvement through a solution pathway of increasing community involvement and participation. To address the conflicting interests amongst different actors in citizen science projects, a solution is to establish a citizen committee for monitoring. To address the issue of a lack of recognition and reliance on short-term benefits, the group discussed solutions for offering incentives or tangible benefits for community involvement. A suitable solution pathway is to explore alternative funding mechanisms for communities and institutions, e.g., at the Ministry for Finance or with the local government. To tackle the language barrier, the proposed solution pathway is to implement citizen training using the local language and engage with indigenous communities. To address the issue of a lack of transparency, the group discussed solutions, including sharing information with the community to build trust.

4. Discussion

4.1. Contribution to State of the Art

This study aimed at identifying and classifying existing barriers and solutions (pathways) to sustainable citizen-based plastic monitoring in fresh waters in Western Africa. Based on our interviews, surveys, and workshop discussions in Ghana, this study has achieved its main goal by revealing diverse types of barriers and solutions to long-term citizen-based plastic monitoring. These results contribute to the existing literature on barriers and solutions identified across a diverse range of citizen science projects.

Various barriers identified in this study have already been discussed in other studies, and could now be confirmed for the Western African context. Those barriers first refer to resources, including financial constraints, a lack of time, and a lack of tools or technology [9,31,32,33,34,47]. Further identified barriers, specifically related to the social category, such as lack of motivation for monitoring activities or language barriers are also consistent with the existing literature that emphasised the role of motivation and language as barriers to citizen science projects [32,48]. Another barrier related to the management and governance category is the lack of infrastructure for water monitoring. This issue adds to the existing literature that discusses management and governance challenges in different regional contexts [32].

The study further confirms the existing literature on solutions and further specifies these solutions for the Western African context. In the technical category, for instance, the implementation of infrastructure for sustainable data management as a prerequisite for long-term citizen-based monitoring could be confirmed [32,49]. Additionally, the results also hint at the role of standardisation of protocols for plastic monitoring to effectively compare and reproduce data results [50]. Especially in the social category, solutions such as on the role of communication methods are consistent with the current state of research: Communication with participants is beneficial at different phases of project implementation. Proper science communication can increase the interest of potential new participants, clear communication strategies can motivate participants to deliver accurate data quality and ensure long-term commitment to the projects [32,47,48,51]. Moreover, the importance of accurately financing and funding citizen science projects and participants through incentives as well as the need for lobbying at respective funding institutions is emphasised, as it is crucial for the long-term implementation and success of such initiatives [33,50,52].

In addition to the studies above, the present work systematically analysed and classified the identified barriers and solutions along the five fields of action to provide a precise overview of the challenges and solutions for implementing long-term citizen science monitoring. In addition to the existing literature, this research has also shown how important these different types of barriers and solutions are, also from various institutional perspectives including the public sector, academia, civil society, and the private sector. In consequence, the research findings enhance our understanding of the complexity of barriers to the implementation of citizen science projects in the long term.

4.2. Discussion of Methods

The mixed-method approach, combining expert interviews with stakeholder surveys and role play, has been effective in grasping this complexity of barriers, solutions, and solution pathways for a sustainable implementation of citizen science projects in the field of plastic monitoring. Expert interviews are a standard approach to data collection, but also come with specific risks such as desired answers in a face-to-face interview situation. Online surveys with stakeholders add a specific stakeholder perspective to the knowledge of experts in a more formalised way, which, however, lacks contextualisation. In contrast to these two approaches, the role play implemented at the stakeholder workshop provides a contextualised perspective on barriers and solutions based on a realistic use case, which is, however, also subject to the dynamics of group discussions.

This complementary strategy revealed that different types of experts still emphasised similar barriers and solutions, predominantly in the social and management and governance categories. However, some variations were observed as interviewees and survey respondents emphasised in part different types of barriers and solutions. For example, in terms of solutions, survey respondents representing different stakeholders on site shared more solutions in the social category than the interviewed experts. Survey respondents focused rather on engagement activities in communities to raise citizens’ awareness of plastic pollution to increase their participation in citizen science projects. On the other hand, experts focused their social solutions on better communication and training of project participants and addressing internal issues in projects. The roundtable discussion changed the perception of key barriers, demonstrating an even more important role of social aspects than was the case in the expert interviews and the survey. This is interesting as different settings for identifying key barriers and solutions lead to different perceptions of barriers and solutions. Also, the actual attribution of barriers and solutions to different categories was not always clear to the participants of the roundtable discussions, demonstrating the need to clearly explain and discuss the concepts used at stakeholder workshops and to agree with all actors involved upon a joint understanding of categories.

4.3. Practical Recommendations

Based on these results, the following suggestions for implementing citizen science in the long-term are key: First, technical and financial assistance has focused on funding sources and knowledge in order to address environmental problems. While knowledge and funding seem indeed to be important for change, our analysis has shown that there exists a wide array of barriers and solutions strategies, which refer to social aspects, management, and governance. These aspects should be taken into consideration when designing or supporting citizen science projects in the long term. Second, different stakeholder groups from academia and the public, private, and civil society sectors may have different preconceptions regarding barriers and solutions to citizen science, specifically with regard to the role and behaviour of citizens involved. It is important to address these preconceptions right from the start of the planning process in order to address potential issues or biased perceptions. Third, different stakeholder groups may have different means to address barriers to citizen science, e.g., at the level of funding, policy, or in interaction with actors on the ground. Any attempts to overcome barriers should, therefore, build upon these different functions of stakeholder groups. One approach could be to invite key players of the four stakeholder groups to a joint workshop to discuss how they can advance citizen science from their specific perspective. However, respective activities have to address potential power dynamics by applying specific mitigation strategies such as the assignment of an external facilitator and the use of facilitation techniques that allow all actors to speak on a level playing field. Respective ideas could be part of the long-term citizen science strategy in Accra.

4.4. Transferability of Results

While the analysis focused on the case of Accra in Ghana, we assume that the results may be similar in comparable cities with regard to problem pressure, interests in applying citizen science approaches, and general context conditions such as the availability of resources. However, different regions may also show different cultural traits such as varying roles of gender. This may influence the ways how women, in particular, can participate in respective activities. Therefore, we also assume that barriers and the respective solution strategies can differ in these various contexts. We, therefore, suggest a comparative approach including countries from different regions to understand which barriers and solutions strategies are key in which geographical context.

5. Conclusions

This analysis of barriers and solutions has first revealed a comprehensive, yet systematised list of barriers and solutions to citizen-based plastic monitoring in Accra, Ghana. The analysis based on our mixed-method approach including interviews, online surveys, and workshop discussions reveals that barriers and solutions strategies go beyond the classic target areas of financial and technical assistance, and span also to the range of social and management and governance as well as technical, financial, and environmental solutions. The role play in our workshop discussions further hints at various perceptions of different stakeholder groups including academia, the public sector, business and industry as well as civil society. While all stakeholder groups emphasise social barriers and solutions strategies, there are also different key barriers and solutions that have been identified. Our results hint at a differentiated strategy to overcome barriers to long-term citizen-based plastic monitoring, which puts particular emphasis on the social aspects just as well as on the various perspectives of different institutional stakeholders on site. The application of such a differentiated solution strategy shall overcome barriers to long-term citizen-based plastic monitoring as a potential strategy to address limited data and actions against plastic pollution in fresh waters. Additional research is needed to verify the validity of the results in the citizen science practice in Ghana and in more comparable cases facing severe plastic pollution, data shortages, and interests in advancing citizen science.