Urban Farmer Vs Ocean: What To Grow On The Sea (& How?) | Growing Wild: Project Castaway - Part 2/3

Project Castaway: Floating Farm Development - Summary

Key Concepts:

• Project Castaway: An initiative to create a sustainable floating farm at sea.
• Aquaculture: The farming of aquatic organisms such as fish, seaweed, and shellfish.
• Salt-tolerant crops (Halophytes): Plants that can grow in saline conditions.
• Integrated Multi-Trophic Aquaculture (IMTA): A farming technique that cultivates multiple species in a single system, utilizing waste from one species as nutrients for another.
• Low Trophic Aquaculture: Farming species lower in the food chain, requiring less feed and having a lower environmental impact.
• Chinampas: Floating platforms for growing crops, inspired by ancient agricultural techniques.
• Retentology: A technology aimed at improving water retention in soil.
• Modular Design: A design approach that uses interchangeable parts or components.

1. Initial Site Assessment and Community Engagement:

• The team visits Sona, Malaysia, specifically Boom Boom Island, to assess the feasibility of establishing a floating farm.
• Dr. Advi, a marine biologist, assists in evaluating the site's conditions, including pH (8.48), salinity (34.41), and temperature (30.35°C).
• Seabed analysis reveals a lack of marine life, indicating the need for careful species selection for cultivation.
• Visits to seaweed farms in Sangaban provide insights into cultivation techniques and challenges faced by local farmers.
• Seaweed (specifically Kappaphycus alvarezii) is farmed for 45 days and used to produce carrageenan, an emulsifier, stabilizer, and thickener in the food industry.
• Farmers face challenges such as "ice-ice" disease, which affects seaweed growth during the rainy season due to excessive rain.
• Meetings with community members (Sabran and Masran) reveal their dependence on coastal resources and their interest in alternative income sources like fish farming.
• Climate change is not a primary concern for the community, highlighting the need for the project to address these issues indirectly.
• Sona is identified as an entry point for high-value coral fishes.
• Rabbitfish, a vegetarian species that consumes seaweed, is considered for aquaculture.

2. Initial Design and Stakeholder Feedback:

• The team develops initial designs for a floating platform, incorporating crops like sorghum, millet, herbs, and vegetables (e.g., kangkong, pak choy, and serai).
• The design includes a rabbitfish farm and seaweed cultivation to prevent turtle predation.
• Stakeholders, including Dr. Idi and Masan, provide feedback on the concept drawing.
• The design aims for self-sufficiency, with rabbitfish consuming seaweed and crop waste.
• The floating farm is envisioned as an educational platform for school children and tourists.

3. Understanding Marine Ecosystems and Aquaculture Techniques:

• Dr. Maxine lectures on healthy marine ecosystems, emphasizing the importance of eating lower on the trophic levels to avoid consuming toxins like mercury.
• Integrated Multi-Trophic Aquaculture (IMTA) is presented as a sustainable approach, but its fragility and potential impact on surrounding reefs are discussed.
• Ricardo Collado at the University of Aveiro shares insights on IMTA systems, emphasizing the importance of ecological harmony and nutrient flow.
• IMTA mimics natural processes, maximizing production without harming the environment.

4. Engineering Challenges and Design Revisions:

• Engineer Walter provides critical feedback on the initial design, deeming it "idealistic" and impractical.
• He suggests moving vegetable trays off the platform to reduce costs and improve accessibility.
• Walter emphasizes the need for a processing area, shade, and modular design for flexibility.
• He raises concerns about the high cost of desalination and suggests rainwater collection.
• The team revises the design based on Walter's feedback, creating a more modular and maintainable platform.
• The new design features a central working area with four aquaculture pots and attachments for floating crop platforms (chinampas).
• Locally sourced materials are prioritized to reduce costs.

5. Aquaculture Practices and Ecosystem Restoration:

• Visits to oyster farmer and sea urchin diver in Saga Prefecture, Japan, provide insights into aquaculture methods and ecosystem restoration.
• The oyster farmer's dedication to ocean cleanliness and efficient farming processes is inspiring.
• The sea urchin diver's work in removing invasive sea urchins and replanting seaweed demonstrates the potential for marine ecosystem rehabilitation.
• The sea urchin conservationist smashes invasive black sea urchins and replants seaweed to restore kelp forests.
• Kesamaruan's facility rears purple sea urchins for consumption, showcasing a sustainable aquaculture model.

6. Plant Stress Testing and Retentology Experiments:

• Salt-tolerant experiments are conducted to determine which crops can withstand saline conditions.
• Plants are tested with varying salinity levels, from freshwater to full seawater.
• Lemongrass, chili, and Sorghum are tested alongside Portulaca oleracea (purslane) as a potential alternative to Salicornia.
• Retentology, a technology to improve water retention in soil, is tested with different application levels.
• Results show that Portulaca oleracea is highly resilient to saline and dry conditions.
• Utensology shows limited effectiveness in windy conditions, requiring additional irrigation.

7. Chinampa Design and Sea Trials:

• The team revises the design of the chinampas, focusing on sturdiness and buoyancy.
• Sea trials are conducted to test the structural integrity of the floating platforms and the survival of the plants.
• The aluminum design proves to be unstable and unbalanced.
• The wooden planter is more stable but raises concerns about its ability to withstand aggressive waves.
• The water reservoir's weight distribution contributes to instability.
• The sea trials are largely unsuccessful, leading to disappointment and the need for further revisions.

8. Conclusion:

Project Castaway faces numerous challenges in its quest to create a sustainable floating farm. Initial designs require significant revisions based on engineering feedback and practical testing. Salt-tolerant experiments reveal the potential of certain crops like Portulaca oleracea, while highlighting the limitations of retentology in harsh marine environments. The team gains valuable insights from local communities and aquaculture experts, emphasizing the importance of ecological harmony and sustainable practices. Despite setbacks in the sea trials, the project continues to evolve, driven by the goal of enhancing food security and promoting sustainable aquaculture in the face of climate change.