Reducing the impacts of plastic waste in the Eastern Pacific Ocean The presence of plastic leaking into the environment is a system failure of monumental proportion that threatens the marine ecosystem and causes physical and chemical contamination at a global scale. It is estimated that 12 million tonnes of plastic enters the oceans each year and this has rapidly become a global concern. The economic damage of this plastic pollution amounts to around USD13 billion per annum due to degraded environments, loss of revenue from tourism, and costs of clean up and repair. This is a particular issue in the Eastern Pacific rim countries of Ecuador and Peru which host seas of great ecological, economic and conservation importance with high levels of endemic species, including fish, reptiles, birds and mammals, found nowhere else on earth. The health of this unique biodiversity is important to one of the world's key fishing areas and a growing tourism industry, supporting a variety of livelihoods and food security for the coastal people, many very poor. The total amount of plastic produced and used in Latin America represents 4% of the plastic produced globally. It has been estimated that 45% of this is inadequately managed, generating around 1 million tonnes of mismanaged plastic waste annually, and predicted to double by 2025 if no action is taken.   This challenge requires a regional scale approach that allows environmental, economic, technical and social disciplines to come together to build understanding of the many factors contributing to the problem, its impacts and how it can be solved. Over the last three years we have established an enthusiastic and engaged network across the region committed to designing and implementing solutions for lasting change in the Eastern Pacific region (specifically seas off Ecuador and Peru). Our network has strong relationships with Research Institutions, National Park managers and Environment Ministries in each country. Our vision is to reduce plastic leakage in the Eastern Pacific region, supporting development of a sustainable, circular economic system for plastics. We propose an integrated, multidisciplinary project with three core aims. We will establish the sources and drivers of plastic pollution including the mapping of waste flows across the region and life cycle assessments of materials used in key industries. Secondly, we will identify the key economic, ecological and health and wellbeing impacts of the current plastic pollution that pervades this region. Thirdly, we will implement and test interventions to mitigate and reduce plastic pollution and help progress the region to circular approaches to plastic.   As we are already working with stakeholders in the region, we have some co-designed interventions ready to test immediately. These innovations range from helping streamlining the monitoring of novel-technology based clean-up operations to trialling an innovative community-based scheme to recycle fishing nets. As part of an exciting region-wide educational campaign to develop targeted awareness-raising for inland and coastal schools and communities, students will be invited to design interventions to minimise urban plastic leakage. We will test the scalability and effectiveness of these ideas. The evaluation of these, in addition to data generated in Theme 1 and Theme 2 will support the design and testing of further social, environmental and technical innovations. To ensure the research achieves the maximum impact, the consortium partners include South American government agencies and departments, NGOs and business with extensive experience of engaging coastal communities in the region and equal partnerships between UK and South American universities to develop local research capacity through collaboration and training. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.