In Southeast Asia, where oceans connect communities and economies, marine plastic pollution has become a pressing transboundary challenge. Plastic waste rarely stays within the borders of its origin. It travels across nations, harming ecosystems and communities along the way, making it not only an environmental issue but also a multi-sector problem that calls for shared responsibility. Understanding and addressing it requires legal and policy frameworks that can guide cooperation across countries and sectors.
As part of ERIA’s Zero in on Plastic series, the Regional Knowledge Centre for Marine Plastic Debris spoke with Associate Professor Nguyen Thi Xuan Son, a leading expert in international and environmental law, to explore the complexities of transboundary marine plastic waste and the opportunities for stronger cooperation in Southeast Asia and beyond.
Assoc. Prof. Son: I am a lecturer in the Faculty of International Law, specialising in international environmental law and international maritime law. I have more than 20 years’ experience in teaching and research in these fields. Currently, I serve as Dean of the Faculty of International Law and Director of the Center for the Law of the Sea and International Maritime Law at the University of Law, Vietnam National University.
I have carried out several research projects and academic activities related to plastic waste. At the University of Law, Vietnam National University, I integrated marine plastic waste management into teaching modules to raise awareness amongst future professionals. I also contributed to a capacity-building needs assessment for Viet Nam, aimed at preparing the country for the Global Plastic Treaty negotiations. In addition, I supported initiatives on Extended Producer Responsibility (EPR) in managing marine plastic litter and explored the role of women working in the informal sector. Beyond these, I have been involved in related projects addressing various aspects of marine plastic waste management.
There is no official definition yet. Based on existing reports and studies, it can be understood as a global issue rather than an environmental challenge confined to a single country. Marine plastic waste moves across national boundaries through ocean currents and trade, creating shared impacts and requiring collective responsibility from all nations.
Plastic waste travels across borders mainly through ocean currents, and its sources are largely linked to human activities. Key contributors include fishing, shipping, and international trade. Improper waste management from coastal facilities, ports, and even island bases also contribute significantly to the problem.
Viet Nam has made notable efforts to align with global initiatives on managing transboundary plastic waste. At the international level, the country actively participates in the ongoing negotiations for a legally binding Global Plastics Treaty under the auspices of the United Nations Environment Assembly (UNEA). This demonstrates the country’s commitment to finding collective solutions that extend beyond national boundaries.
Regionally, Viet Nam has engaged with ASEAN frameworks, including the ASEAN Regional Action Plan for Combating Marine Debris (2021–2025), which emphasises cooperative measures such as reducing plastic inputs into the ocean, promoting circular economy practices, and strengthening monitoring systems.
Domestically, Viet Nam has introduced policies that reflect international best practices. For example, the National Action Plan on Marine Plastic Waste Management to 2030 sets ambitious targets to reduce plastic leakage into the ocean, enhance EPR, and promote public–private partnerships in waste management. These measures are consistent with global approaches and reinforce Viet Nam’s role as a proactive partner in addressing transboundary plastic waste.
A key challenge is that marine plastic waste often affects countries that did not generate it, particularly developing nations with limited capacity to manage such pollution. This creates an imbalance between waste-exporting countries and those suffering the consequences. Moreover, this type of pollution cannot be effectively addressed through the laws of a single state, as it requires regional and international coordination. Yet progress depends on national policies and jurisdictions, which may vary widely. The lack of alignment between national, regional, and international frameworks remains a major obstacle to effective cooperation.
In the ASEAN region, most cooperation on environmental protection, including plastic waste, has been built on ‘soft law’ instruments. ASEAN has addressed plastic waste mainly through the ASEAN Framework of Action on Marine Debris (2019) and the Regional Action Plan on Combating Marine Debris in ASEAN Member States (2021–2025).
While these are generally non-binding agreements or political commitments rather than legally enforceable treaties, such instruments play an important role in shaping regional environmental governance and fostering cooperation amongst member states. However, moving towards a binding international agreement on plastic waste remains challenging, and progress towards a final framework is slow and complex.
Differences in national waste management systems pose a significant challenge to regional cooperation. Much like in other areas of international environmental governance, aligning diverse national interests is not easy. These differences stem from varying levels of economic development, political priorities, and institutional capacities. As a result, it is difficult to establish a unified approach.
Even if a global agreement is reached, the real fight is in deciding how to implement it. The next step depends on each country because we are living in a very troubling situation, and national interest remains the most important factor – not only in working towards an international agreement but also in implementing it.
Harmonising policies across ASEAN is challenging because of differences in economic development and varying policy priorities. It is not easy to reach a common position. However, countries such as Viet Nam, Thailand, the Philippines, and Indonesia share similar concerns and have begun developing policies that address marine plastic pollution. Building on these shared interests could provide a foundation for greater regional cooperation. Still, achieving true policy harmonisation will take time and sustained political will, as aligning diverse national contexts is inherently complex.
International laws and agreements provide a shared framework for cooperation, as they set common standards and responsibilities. However, to make such agreements effective and legally binding, countries must often amend their national laws and policies to align with international commitments. This requires transparency, legal reforms, and strong policy mechanisms to ensure that global commitments are translated into national action.
I would recommend the development of a regional roadmap for addressing plastic and marine plastic waste. This roadmap should prioritise reducing plastic consumption, promoting a circular economy, and enhancing knowledge sharing and capacity building amongst countries. These measures would build on common concerns and shared interests within ASEAN and serve as a practical foundation for strengthening transboundary cooperation.
I believe ASEAN offers important opportunities through its cooperation mechanisms. Regional collaboration not only enables countries to share knowledge but also generates collective benefits by strengthening capacity and aligning actions to address marine plastic waste more effectively.
Given the diversity of contexts across countries, I believe one of the most important areas is research on capacity building and public awareness. In Viet Nam, for example, greater attention is needed on how to raise awareness of marine plastic issues at different levels of society – from grassroots communities and to high schools, secondary schools, and universities. Identifying the most effective methods of education and outreach can provide valuable insights for developing long-term solutions.
To develop more integrated responses to marine plastic pollution, I would emphasise three dimensions of coordination:
Horizontal cooperation (between countries):
Nations must work together under regional and global frameworks. Mechanisms such as UNEP’s Regional Seas Programme demonstrate the value of intergovernmental structures for addressing marine litter. Similarly, international conventions have adopted ecosystem-based protocols on marine litter and hazardous movements, showing the importance of unified cross-border action.
Vertical integration (between levels of government):
Effective solutions require alignment between central governments and local authorities. National policies must be translated into local action plans, while local data and innovation should inform national strategies. Local governments also need sufficient resources and clear guidelines to implement plastic reduction measures, manage cleanups, and strengthen monitoring systems.
Cross-sector collaboration (between ministries and stakeholders):
Marine plastic waste is not only an environmental issue but also an economic and social one. Ministries of environment, industry, fisheries, and tourism must coordinate policies to avoid working at cross-purposes. A multi-sectoral approach, grounded in science and environmental economics, can ensure more coherent and effective governance.
Assoc. Prof. Son’s reflections highlight the need for coordinated policies and governance at multiple levels in managing transboundary marine plastic waste. From aligning national regulations with international agreements to strengthening ASEAN frameworks, the path forward depends on collaboration, knowledge sharing, and sustained political will. Her insights show that progress is possible, but only when commitments are translated into concrete action.
Dean of the Faculty of International Law and Director of the Center for the Law of the Sea and International Maritime Law at the University of Law, Vietnam National University
In Southeast Asia, where oceans connect communities and economies, marine plastic pollution has become a pressing transboundary challenge. Plastic waste rarely stays within the borders of its origin. It travels across nations, harming ecosystems and communities along the way, making it not only an environmental issue but also a multi-sector problem that calls for shared responsibility. Understanding and addressing it requires legal and policy frameworks that can guide cooperation across countries and sectors.
As part of ERIA’s Zero in on Plastic series, the Regional Knowledge Centre for Marine Plastic Debris spoke with Associate Professor Nguyen Thi Xuan Son, a leading expert in international and environmental law, to explore the complexities of transboundary marine plastic waste and the opportunities for stronger cooperation in Southeast Asia and beyond.
Assoc. Prof. Son: I am a lecturer in the Faculty of International Law, specialising in international environmental law and international maritime law. I have more than 20 years’ experience in teaching and research in these fields. Currently, I serve as Dean of the Faculty of International Law and Director of the Center for the Law of the Sea and International Maritime Law at the University of Law, Vietnam National University.
I have carried out several research projects and academic activities related to plastic waste. At the University of Law, Vietnam National University, I integrated marine plastic waste management into teaching modules to raise awareness amongst future professionals. I also contributed to a capacity-building needs assessment for Viet Nam, aimed at preparing the country for the Global Plastic Treaty negotiations. In addition, I supported initiatives on Extended Producer Responsibility (EPR) in managing marine plastic litter and explored the role of women working in the informal sector. Beyond these, I have been involved in related projects addressing various aspects of marine plastic waste management.
There is no official definition yet. Based on existing reports and studies, it can be understood as a global issue rather than an environmental challenge confined to a single country. Marine plastic waste moves across national boundaries through ocean currents and trade, creating shared impacts and requiring collective responsibility from all nations.
Plastic waste travels across borders mainly through ocean currents, and its sources are largely linked to human activities. Key contributors include fishing, shipping, and international trade. Improper waste management from coastal facilities, ports, and even island bases also contribute significantly to the problem.
Viet Nam has made notable efforts to align with global initiatives on managing transboundary plastic waste. At the international level, the country actively participates in the ongoing negotiations for a legally binding Global Plastics Treaty under the auspices of the United Nations Environment Assembly (UNEA). This demonstrates the country’s commitment to finding collective solutions that extend beyond national boundaries.
Regionally, Viet Nam has engaged with ASEAN frameworks, including the ASEAN Regional Action Plan for Combating Marine Debris (2021–2025), which emphasises cooperative measures such as reducing plastic inputs into the ocean, promoting circular economy practices, and strengthening monitoring systems.
Domestically, Viet Nam has introduced policies that reflect international best practices. For example, the National Action Plan on Marine Plastic Waste Management to 2030 sets ambitious targets to reduce plastic leakage into the ocean, enhance EPR, and promote public–private partnerships in waste management. These measures are consistent with global approaches and reinforce Viet Nam’s role as a proactive partner in addressing transboundary plastic waste.
A key challenge is that marine plastic waste often affects countries that did not generate it, particularly developing nations with limited capacity to manage such pollution. This creates an imbalance between waste-exporting countries and those suffering the consequences. Moreover, this type of pollution cannot be effectively addressed through the laws of a single state, as it requires regional and international coordination. Yet progress depends on national policies and jurisdictions, which may vary widely. The lack of alignment between national, regional, and international frameworks remains a major obstacle to effective cooperation.
In the ASEAN region, most cooperation on environmental protection, including plastic waste, has been built on ‘soft law’ instruments. ASEAN has addressed plastic waste mainly through the ASEAN Framework of Action on Marine Debris (2019) and the Regional Action Plan on Combating Marine Debris in ASEAN Member States (2021–2025).
While these are generally non-binding agreements or political commitments rather than legally enforceable treaties, such instruments play an important role in shaping regional environmental governance and fostering cooperation amongst member states. However, moving towards a binding international agreement on plastic waste remains challenging, and progress towards a final framework is slow and complex.
Differences in national waste management systems pose a significant challenge to regional cooperation. Much like in other areas of international environmental governance, aligning diverse national interests is not easy. These differences stem from varying levels of economic development, political priorities, and institutional capacities. As a result, it is difficult to establish a unified approach.
Even if a global agreement is reached, the real fight is in deciding how to implement it. The next step depends on each country because we are living in a very troubling situation, and national interest remains the most important factor – not only in working towards an international agreement but also in implementing it.
Harmonising policies across ASEAN is challenging because of differences in economic development and varying policy priorities. It is not easy to reach a common position. However, countries such as Viet Nam, Thailand, the Philippines, and Indonesia share similar concerns and have begun developing policies that address marine plastic pollution. Building on these shared interests could provide a foundation for greater regional cooperation. Still, achieving true policy harmonisation will take time and sustained political will, as aligning diverse national contexts is inherently complex.
International laws and agreements provide a shared framework for cooperation, as they set common standards and responsibilities. However, to make such agreements effective and legally binding, countries must often amend their national laws and policies to align with international commitments. This requires transparency, legal reforms, and strong policy mechanisms to ensure that global commitments are translated into national action.
I would recommend the development of a regional roadmap for addressing plastic and marine plastic waste. This roadmap should prioritise reducing plastic consumption, promoting a circular economy, and enhancing knowledge sharing and capacity building amongst countries. These measures would build on common concerns and shared interests within ASEAN and serve as a practical foundation for strengthening transboundary cooperation.
I believe ASEAN offers important opportunities through its cooperation mechanisms. Regional collaboration not only enables countries to share knowledge but also generates collective benefits by strengthening capacity and aligning actions to address marine plastic waste more effectively.
Given the diversity of contexts across countries, I believe one of the most important areas is research on capacity building and public awareness. In Viet Nam, for example, greater attention is needed on how to raise awareness of marine plastic issues at different levels of society – from grassroots communities and to high schools, secondary schools, and universities. Identifying the most effective methods of education and outreach can provide valuable insights for developing long-term solutions.
To develop more integrated responses to marine plastic pollution, I would emphasise three dimensions of coordination:
Horizontal cooperation (between countries):
Nations must work together under regional and global frameworks. Mechanisms such as UNEP’s Regional Seas Programme demonstrate the value of intergovernmental structures for addressing marine litter. Similarly, international conventions have adopted ecosystem-based protocols on marine litter and hazardous movements, showing the importance of unified cross-border action.
Vertical integration (between levels of government):
Effective solutions require alignment between central governments and local authorities. National policies must be translated into local action plans, while local data and innovation should inform national strategies. Local governments also need sufficient resources and clear guidelines to implement plastic reduction measures, manage cleanups, and strengthen monitoring systems.
Cross-sector collaboration (between ministries and stakeholders):
Marine plastic waste is not only an environmental issue but also an economic and social one. Ministries of environment, industry, fisheries, and tourism must coordinate policies to avoid working at cross-purposes. A multi-sectoral approach, grounded in science and environmental economics, can ensure more coherent and effective governance.
Assoc. Prof. Son’s reflections highlight the need for coordinated policies and governance at multiple levels in managing transboundary marine plastic waste. From aligning national regulations with international agreements to strengthening ASEAN frameworks, the path forward depends on collaboration, knowledge sharing, and sustained political will. Her insights show that progress is possible, but only when commitments are translated into concrete action.
Dean of the Faculty of International Law and Director of the Center for the Law of the Sea and International Maritime Law at the University of Law, Vietnam National University
