Drivers of plastic waste reduction in island communities in Central Vietnam: An application of the extended theory of planned behavior

• This study examined what drives plastic waste reduction among island residents. • The analysis employed the TPB model, incorporating trust and tourist morality. • Perceived behavioral control and trust strongly predict the behavior on islands. • Anti-plastic interventions improved attitudes, norms, and behaviors. • Tourism boosts clean-ups but hinders psychological factors and behaviors. Marine plastic pollution threatens coastal and island communities. Initiatives to reduce plastic have raised awareness and stimulated behavioral changes among local populations. The tourism sector represents a complex dynamic, serving as a significant industry that bolsters numerous communities’ local economies. While tourism contributes to increased plastic consumption, it also has the potential to support pollution mitigation efforts to preserve the reputation of these destinations. This study aims to examine the attitudes and behaviors in reducing marine plastic pollution, with particular attention to the impact of interventions and tourism, as there remains a shortage of understanding regarding the drivers that affect waste reduction in island contexts. Data were collected from 300 residents on two neighboring islands in Central Vietnam through questionnaires developed based on the Theory of Planned Behavior (TPB) with an extension to tourists’ moral behaviors and trust in authority. The Kruskal-Wallis tests and path analysis revealed that interventions substantially improved plastic waste reduction behaviors. Furthermore, all factors within the TPB framework and its extensions displayed positive correlations with intention and behavior; notably, perceived behavioral control and trust in authority exhibited stronger associations than other variables. Interventions were identified as positive predictors of behavioral change, likely attributable to educational activities, the distribution of reusable bags, and community engagement initiatives. Conversely, tourism was found to exert mixed effects: it could discourage anti-plastic practices, possibly due to economic priorities, while encouraging such practices when tourists exemplify pro-environmental behaviors. Essential policy implications for marine plastic pollution within island communities were discussed.