Brand audit attribution of plastic litter in the African Great Lakes: dominance of national manufacturers and implications for extended producer responsibility.

Plastic pollution is an established environmental crisis, but the responsibility of specific producers remains poorly understood particularly in freshwater systems. The present study applies brand audit-based attribution to identify the manufacturers associated with branded plastic litter collected during a large-scale citizen science clean-up campaign across the Tanzanian shorelines of the African Great Lakes (Lakes Victoria, Tanganyika, and Nyasa (Malawi), A dataset of 11,207 litter items with visible and validated branding was dominated by plastics (9951 items, 88.8%), mainly comprised of single use "fast-moving consumer goods". Beverage bottles constituted the largest plastic item category (64.9%), followed by soft packaging (1379 items, 13.9%) and food wrappers (1242 items, 12.5%). In total, 292 brands and 148 manufacturers were identified. Corporate contributions were highly concentrated, with three manufacturers (Jambo Group of Companies, Bakhresa Food Products Ltd, and MeTL Group) accounting for 52.9% of branded plastic litter, while 29 manufacturers explained 95.1%. Overall, 91.4% of branded plastic litter was attributable to Tanzanian manufacturers, with regional and international manufacturers representing minor fractions. This pronounced concentration and national embedding of responsibility suggest that Extended Producer Responsibility (EPR) frameworks may be particularly feasible in this context. Coordinated and transparent action to finance waste infrastructure and implement EPR mechanisms, such as bottle return schemes, would send a clear and credible signal of commitment to pollution mitigation. Whilst community-led clean-ups have an important role, without parallel producer responsibility measures and infrastructure development, the burden of waste management continues to fall disproportionately on local communities.