How Ocean Farming Can Become a Powerful Tool for Ecosystem Restoration

• February 17, 2025

Ocean farming has long been seen as a solution to meet the world’s growing demand for seafood. However, traditional aquaculture practices often come with environmental concerns. Have you heard about Integrated Multi-Trophic Aquaculture (IMTA), a revolutionary approach that’s transforming ocean farming into ecosystem restoration hubs? IMTA is an innovative farming method that mimics natural ecosystems by cultivating multiple species from different trophic levels together. This approach not only produces a variety of seafood but also provides significant environmental benefits.

The IMTA Advantage

Pollution Reduction
One of the most significant advantages of IMTA is its ability to reduce pollution. In traditional aquaculture, waste from fed species like fish can lead to nutrient pollution and water quality degradation. IMTA addresses this by incorporating extractive species such as shellfish and seaweed. Shellfish, like mussels and oysters, act as natural filters, removing excess nutrients and organic waste from the water. Seaweed, on the other hand, absorbs dissolved nutrients like nitrogen and phosphorus. This natural biofiltration system significantly reduces the nutrient load in the aquaculture environment, preventing eutrophication and improving overall water quality.

Biodiversity Enhancement
IMTA systems don’t just reduce pollution; they actively contribute to enhancing marine biodiversity. By creating a more balanced and diverse ecosystem, IMTA promotes a healthier marine environment. The presence of multiple species in IMTA systems creates a more complex habitat that supports a greater diversity of marine life. This increased biodiversity can help restore degraded ecosystems and promote the recovery of local marine populations.

Economic Benefits
Beyond its environmental advantages, IMTA also offers significant economic benefits. By producing multiple species in the same system, IMTA diversifies income streams for farmers. This approach can help reduce economic risks associated with monoculture farming and create new market opportunities.Moreover, the improved environmental performance of IMTA systems can lead to reduced operational costs. For instance, the natural biofiltration provided by extractive species can decrease the need for artificial filtration systems.

PHAROS and the Future of IMTA for Sustainable Ocean Farming

The PHAROS project is advancing IMTA practices for sustainable ocean farming. Through innovative research and pilot projects, PHAROS is demonstrating the potential of IMTA to transform aquaculture into a more sustainable and environmentally friendly industry. PHAROS’s work focuses on optimising nutrient recycling within IMTA systems, effectively reducing aquaculture’s ecological footprint. By fine-tuning the balance between fed and extractive species, PHAROS is helping to maximise the efficiency of nutrient uptake and waste reduction in IMTA systems .One of the key areas of PHAROS’s research is the integration of seaweed cultivation in IMTA systems. Seaweed not only absorbs excess nutrients but also contributes to carbon sequestration, playing a crucial role in mitigating climate change impacts. PHAROS is also exploring the potential of IMTA in different environments, from coastal waters to offshore installations. This research is crucial for adapting IMTA practices to various ecological contexts and scaling up its implementation.

Shift in Ocean Farming

IMTA represents a paradigm shift in ocean farming, transforming it from a potential environmental threat into a tool for ecosystem restoration. By mimicking natural ecosystems, IMTA not only produces food but also provides valuable ecosystem services.As we look to the future of sustainable seafood production, IMTA stands out as a promising solution. With continued research and development, particularly through projects like PHAROS, IMTA has the potential to revolutionise the aquaculture industry, creating a more sustainable and resilient blue economy.The journey towards sustainable ocean farming is ongoing, but with IMTA, we’re taking significant strides in the right direction. As we continue to refine and expand IMTA practices, we move closer to a future where ocean farming not only feeds the world but also helps restore and protect our precious marine ecosystems.

References:

• Chopin, T., Cooper, J. A., Reid, G., Cross, S., & Moore, C. (2012). Open-water integrated multi-trophic aquaculture: Environmental biomitigation and economic diversification of fed aquaculture by extractive aquaculture. Reviews in Aquaculture, 4(4), 209-220.
• Fang, J., Zhang, J., Xiao, T., Huang, D., & Liu, S. (2015). Integrated multi-trophic aquaculture (IMTA) in Sanggou Bay, China. Aquaculture Environment Interactions, 8, 201-205.
• Food and Agriculture Organization of the United Nations. (n.d.). Integrated multitrophic aquaculture: lessons from China. Retrieved February 11, 2025, from https://openknowledge.fao.org/server/api/core/bitstreams/4f50c8be-22df-4f6a-a092-93791d2cc491/content
• Hughes A. D., & Black, K. D. (2016). Going beyond the search for solutions: understanding trade-offs in European integrated multi-trophic aquaculture development. Aquaculture Environment Interactions, 8, 191-199.
• Van Osch, S., Hynes, S., O’Higgins, T., Hanley, N., Campbell, D., & Freeman, S. (2019). Estimating the Irish public’s willingness to pay for more sustainable salmon produced by integrated multi-trophic aquaculture. Marine Policy, 99, 1-12.