Community-based interventions to mitigate marine plastic pollution along the Lagos–Badagry coastal Corridor, Nigeria

Introduction Global plastic production has increased substantially over recent decades, with large quantities entering marine environments. However, effective community-level mitigation strategies remain limited in many low- and middle-income countries. This study illustrates the potential of a community-based intervention aimed at improving plastic waste management practices along the Lagos–Badagry coastal corridor, Nigeria. Methods A mixed methods of data collection (quantitative and qualitative approaches) and quasi-experimental design were employed, involving baseline, post-intervention, and six-month follow-up assessments. Data were collected using structured questionnaires administered by interviewers on 624 respondents at an intervention community (Idado community) and a comparable coastal community (Orimedu), served as the control community, key informant interviews, and physical waste characterization. The intervention consisted of capacity-building workshops as a potential value-added application of recovered plastic waste into road pavers within the context of circular economy education. Results Results showed significant improvements in knowledge (51.3% to 97.7%) and positive attitudes (24.0% to 92.4%) toward plastic waste management ( p  < 0.001). Willingness to engage in waste segregation and recycling increased from 47.8% at baseline to 97.7% at follow-up. Financial incentives (58.6%) and environmental concerns (37.3%) emerged as the primary motivators for behavioural change. Positive attitude (AOR = 4.46, 95% CI: 2.99–6.64, p  < 0.001) were the strongest predictors of willingness to practice plastic waste recycling and circular economy. Waste characterization revealed that beverage bottles (41.8%), plastic ropes (22.6%), plastic cups and plates (5.1%), and bottle caps (3.1%) constituted the dominant plastic waste fractions along the coastline. Discussion These findings demonstrate that community-driven interventions combining environmental education with economic incentives can significantly improve waste management behaviors and reduce marine plastic pollution. Scaling such approaches could support sustainable coastal management and circular economy transitions in similar contexts.