The management and reduction of plastic pollution by municipal governments

Plastic pollution is a burgeoning global issue that has detrimental impacts on the health, wildlife, economies and livelihoods of our terrestrial, coastal, and marine communities and ecosystems. Given the exponential rise in plastic pollution entering the environment, and the growing awareness of this issue, governments are increasingly turning their efforts to the development and implementation of policies and strategies to effectively manage and reduce this pollution and its associated harm. Although international organisations and national and state governments enact change and legislation that address mitigation and reduction of plastic pollution, it is primarily the responsibility of municipal governments to implement strategies on-ground that fulfil the legislative directives and policies. While each municipal government implements numerous strategies, the effectiveness of these measures often goes untested. Consequently, municipal governments and waste managers do not know what strategies are working, what strategies they should be focussing their efforts on and where improvements can be made to achieve better management of waste. The overall objective of the research was to investigate how crucial on-ground municipal waste management teams are responding to the exponential rise in plastic pollution and what styles of management strategies are best at reducing it. This research conducted the first continent-wide evaluation of municipal government strategies to evaluate the relationship between such strategies and coastal litter. Focussing on Australian municipalities, the research undertaken explored what strategies have been used to reduce plastic pollution, whether these strategies have changed over a 6-year period, what has driven municipalities to change their strategies, and the effect changes in strategies have had on plastic pollution in the Australian coastal environment. This thesis begins with a general introduction of the context, state of knowledge, and scale of the issue in Chapter 1. As most of the plastic pollution in the coastal environment is sourced from urban centres, Chapter 2 investigates the historical accumulation trend of plastic pollution from one of Australia's oldest urban centres, Hobart, Tasmania. The research employed a novel method of enumerating microplastics in isotopic-aged sediment cores from an urbanised estuary and showed that plastic has accumulated in the sediment at a similar rate to global plastic production. Chapter 3 evaluates the types of municipal strategies that were most effective at reducing plastic pollution from entering the environment in 2013. Specifically, this chapter explores the success of using infrastructure, policies, and outreach programs in reducing plastic pollution along the Australian coastline. The chapter demonstrates that a combination of community engagement through outreach programs and adequate waste infrastructure was the most successful catalyst for reducing plastic pollution across Australia's coastal regions at a national scale. Chapters 4 and 5 build upon this finding by assessing how plastic pollution and waste management have changed across Australia between 2013 and 2019. This component of the thesis involved conducting follow up interviews with municipal waste managers and resurveying the density and distribution of plastic pollution along the Australian coastline at a national scale. Chapter 4 introduces a theoretical framework that combines the Theory of Planned Behaviour, Situational Crime Prevention and Economic Rationality, and explores whether municipal waste managers have changed their plastic pollution management efforts and what factors have driven those changes. Chapter 5 investigates whether these strategic changes have led to a reduction in plastic pollution observed along the Australian coastline. Next, Chapter 6 presents a case study that focused on how to best implement actions to yield a reduction in a specific type of plastic pollution, one that is abundant and widespread, beverage containers. Here, the research investigates the success of installing water refill stations to reduce plastic bottle litter along an urbanised river, showing that the correct placement and implementation of litter reduction strategies are critical to their success. Chapter 7 provides an overall synthesis and discussion of the results and implications from each chapter. Together, this thesis investigates and highlights the diverse ways in which municipal governments are successfully reducing plastic pollution. Australian municipal governments have changed their waste management strategies over the last 6 years with most increasing their efforts towards strategies that simplify waste disposal for the community and using financial incentives/disincentives to reduce the consumption and littering of plastic products. The theoretical framework proved valuable in framing and analysing the styles and drivers of plastic pollution management strategies employed by municipalities around Australia and how these strategies have changed over a 6-year period. The findings underline the importance of municipalities adapting their strategies and efforts to the social and environmental nuances of their jurisdiction and highlight the important role local management plays in successfully reducing the global issue of plastic pollution. Knowledge of what strategies work best in which environmental and social contexts will enable managers around the world to focus their efforts and resources towards strategies that can successfully reduce plastic pollution and the harm it has on the environment, wildlife, people and economies.