Hannah Grace Gillespie

Sustainable eucheumatoid farming at scale: Assessing pathways for growth in the seaweed industry

Scaling macroalgae (seaweed) aquaculture offers both environmental and socioeconomic benefits, including enhanced livelihoods for coastal communities. Yet, rapid expansion can disrupt marine ecosystems and trigger “boom-and-bust” cycles for smallholder farmers. Eucheumatoids—tropical red seaweeds cultivated in Southeast Asia and Tanzania—contain a valuable gelling agent known as carrageenan. As new applications (e.g. bioplastics) drive global interest in carrageenan, it is critical to identify pathways for the sustainable growth of the eucheumatoid industry.

This study addresses a gap between technical and socio-economic research in seaweed literature through a systems thinking approach. Industry-relevant variables were extracted from peer-reviewed and grey literature and refined through semistructured interviews with nine expert stakeholders. The influence of each variable on all others was assessed and plotted using a MICMAC matrix to evaluate influence and dependency levels. Relationships among these variables were then modelled in a causal loop diagram (CLD). Triangulation of CLD network analysis with data from literature, interviews, and MICMAC rankings allowed the identification of the most significant leverage points in the eucheumatoid industry. From this, five pathways were defined, detailing barriers, interventions, intended benefits, and potential unintended consequences. These pathways align with findings in related literature while providing additional nuance regarding cascading impacts and system-wide interactions, highlighting the strength of a systems analysis approach towards sustainable development.

Three major contributions emerge from this research. First, the Sustainable, Resilient, and Equitable (SRE) Framework defines the characteristics of a thriving eucheumatoid industry. Second, the CLD which may form a foundational map for future systems analysis. Finally, a public online dashboard1 presents the CLD and the identified growth pathways. Public dissemination of the CLD also facilitates ongoing stakeholder engagement and iterative model refinement. The results from this study are useful to smallholder seaweed farmers, policy makers, researchers, and other stakeholders with power to shape the future of the eucheumatoid industry.