Review of Biogas Production and Biomethane Potential of Fish Waste

The increasing volumes of fish waste generated by South Africa’s fishing and aquaculture industries create environmental challenges while offering potential avenues for renewable energy generation. The current energy mix in South Africa is primarily dependent on coal, while renewable sources represent only a minor fraction of the total supply. This systematic review evaluates the potential of fish waste for biogas and biomethane production within the context of South Africa’s Just Energy Transition. A total of 39 studies were analysed for biogas yield, methane content, and operational parameters. Results indicate that fish waste is a viable substrate, with co-digestion often improving yields, though findings are inconsistent. Extreme heterogeneity (I² = 100 %) limits pooled interpretation, highlighting the need for standardized methodologies. Environmental and economic assessments were largely descriptive, underscoring gaps in sustainability metrics. Future research should adopt uniform reporting standards and integrate life-cycle and cost-benefit analyses to inform policy and practice.