INTEGRATED MULTI-TROPHIC AQUCULTURE – HOW GEOPOLITICS CAN IMPACT ITS VIABILITY AND SUSTAINABILITY AS MUCH AS ECOLOGY OR BIOLOGY

Ecological aquaculture, or polyculture, has been practiced for centuries in Southeast Asia and Africa but is still relatively uncommon in Western countries (Beveridge and Little, 2021). In Australia, as in other regions, commercial aquaculture is increasingly facing criticism for environmental impacts and product quality (Mazur and Curtis, 2006). With growing interest in seaweed and the circular economy in Western economies, we examined whether seaweed farming within an Integrated Multi-Trophic Aquaculture (IMTA) model could improve environmental and economic outcomes and boost social acceptance of aquaculture.

Our findings showed that while seaweed can be grown successfully in Australia alongside higher trophic-level species (Visch et al., 2024), there were several non-biological challenges which could influence the success of IMTA:

• Regulations: Strict policies focused on biosecurity or conservation agendas often limit co-production of species due to licensing and proximity rules.
• Public Perception: Many people misunderstand the nutrient cycling and nature positive benefits in IMTA, leading to concerns about using waste streams to feed other species which are produced for human consumption.
• Business Models: Building integrated business models or IMTA partnerships is complex and often implemented retrospectively.
• Conflicting Priorities: There’s often a mismatch between economic growth goals and environmental sustainability.

These challenges may discourage farmers and companies from adopting IMTA or reduce its effectiveness limiting the benefits that IMTA could offer like improved waste management, better nutrition from a more diverse range of aquaculture products, and more efficient resource use. To achieve sustainable outcomes, we must promote the value of integration at ecosystem, operational, political, and societal levels. Aligning policies and governance with new aquaculture practices like IMTA could help communities and markets better understand and support these initiatives, avoiding outcomes that undermine sustainability.