Wastewater aquaculture: perpetuating vulnerability or opportunity to enhance poor livelihoods?

Definitions for wastewater, aquaculture and direct and indirect reuse addressing both technical and sociopsychological considerations are presented to guide the review. Evidence of wastewater aquaculture from historical and contemporary accounts demonstrates that the practice has a long tradition, and it is currently widespread, with examples cited from diverse geographical, environmental and sociopolitical settings. Outcomes of this review demonstrate that some poor people depend both directly and indirectly on wastewater aquaculture for a significant part of their livelihood, whereas society more generally benefits from appropriately managed wastewater reuse. Wastewater reuse contributes to environmental protection, reduced public health risks and the supply of environmental goods and services, which often play an important role in poor livelihoods. However, various constraints, including urbanisation, labour migration, erosion of a competitive advantage, uncertainty over wastewater supplies, contamination, health concerns, operational constraints and ineffective policies, institutions and processes, combined with rising expectations and changing perceptions, mean traditional farming practices and coping strategies are threatened. Conclusions of this review include the need to understand better the importance of wastewater aquaculture in poor livelihoods and to communicate this effectively to policymakers, enabling them to confront the realities of wastewater aquaculture, and where appropriate, support livelihood diversification, thereby lessening the vulnerability associated with this practice.