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Systematic Review ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 1 ? Systematic review or meta-analysis. Synthesizes findings across many studies. Strongest evidence. Sign in to save

From Source to Sea: The Role of River Basins in Marine Pollution Under Development and Climate Change Variability in SADC

Pollutants 2026
Alfredo Pedro Mabica, Sérgio Mateus Chilaule, Isidro José Tamele

Summary

This review of 30 studies found that rivers in Southern Africa are carrying plastics, chemicals, and untreated sewage into the ocean, largely because many cities lack proper wastewater treatment and pollution laws aren't well enforced across borders. This matters because these pollutants—including microplastics—end up in coastal waters where people fish and swim, and climate change is making the problem worse by triggering more floods and straining already weak sanitation systems.

Study Type Review

This article presents a systematic review of land-based marine pollution in the Southern African Development Community (SADC), focusing on the river–sea interface. Using the PRISMA protocol, 30 articles published between 2015 and 2025 were selected. Key pollutants identified include microplastics, nutrients, heavy metals, and urban effluents, which travel through river basins and impact coastal ecosystems and communities. The region faces serious challenges due to limited wastewater treatment coverage, with many urban areas lacking adequate infrastructure or using outdated technologies. This leads to widespread discharge of untreated effluents into rivers. Fragmented governance, weak institutional capacity, and insufficient implementation of regional treaties further hinder pollution control. Climate change exacerbates these pressures by increasing hydrological extremes and the vulnerability of sanitation systems. Despite existing legal instruments, cooperation on monitoring and wastewater management remains limited. The integration of basin and coastal planning, improved governance, and transboundary collaboration are essential to reduce pollution and promote ecological and social resilience in the region.

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