“New Horizons in Coral Replacement: Technology for the Sea”

Coral substitute materials are human-made materials developed to help restore degraded or damaged coral reefs. Their primary purpose is to serve as “infrastructure” for new corals to attach, grow, and reestablish healthy marine ecosystems. These materials can be categorized into several types:

Concrete (e.g., Reef Balls or concrete blocks)

• Advantages: Strong, durable, easy to produce and install
• Cautions: May degrade in seawater over time if not specially designed

Ceramics

• Advantages: Smooth surface, suitable texture for coral larvae to attach
• Drawback: More expensive than concrete

Metals (e.g., steel frames)

• Often used to create complex artificial reef structures, such as fish- or sea creature-shaped reefs
• Drawback: Can rust if not properly coated

Natural materials (e.g., seashells, stones, bamboo)

• Biodegradable and environmentally friendly
• Drawback: Short lifespan

Biopolymers or bio-based materials

• Synthetic materials that are biodegradable and non-toxic
• In development in many countries, using materials like algae-based or marine protein-based compounds

Key Criteria for Coral Substitutes

• Must not release toxic substances into the sea
• Must withstand wave and current forces
• Must have surface texture suitable for coral larvae attachment
• Should not trap sediment or debris
• Should promote biodiversity in marine ecosystems