Supplying fish for protein to a growing population in a sustainable way and without damaging the precious aquatic environment is a huge challenge.
With the world’s ever increasing demand for protein, aquaculture, or fish farming, will play a vital role.
Added to pressure of supply and demand, climate-change consequences also challenge the industry:
- Rising sea temperatures affect the viability of natural marine habitats and further limit insufficient stocks of fish for food in open waters.
- Increased frequency and intensity of storms already cause catastrophic damage to fish farms.
The problems with synthetic farming technology
The technological aspects of fish farming are relatively simple and straightforward: the fish need to be contained in a controlled environment so that they can grow and be harvested at maturity. Traditional fish enclosures are made of petroleum-based, synthetic materials (e.g., nylon), which are adequate for containing fish but present a variety of problems:
- Weak, synthetic materials are susceptible to damage from storms, leading to catastrophic losses for fish farmers and disruption in food supply chains.
- Synthetic materials are vulnerable to prey (sea lions, seals, sharks, etc.), which can puncture the enclosures and lead to fish escapes.
- Synthetic materials are highly susceptible (near 100 percent occurrence) to biofouling, growth of organic materials on the netting itself.
- Short service life (about three months)
- High level of expensive and energy-intensive maintenance
- Contaminated fish, which may require antibiotics
- Environmental concerns with end-of-life disposal due to nonrecyclable synthetic materials and transfer of biofouled enclosures to land environments.
These challenges increase the carbon footprint of the global fish-farming industry.
Sustainable fish farming with copper-alloy netting
Copper-alloy mesh in aquaculture addresses the key challenges facing the fish-farming industry globally, in a more sustainable way, while improving economics for fish farmers. The benefits of this new technology are diverse and significant:
- Climate-change adaptation
- Strong copper-alloy mesh capable of withstanding harsh conditions farther offshore
- With increased occurrence and intensity of storms, expectation that current fish-farming technologies will increasingly fail during adverse weather events
- Reduced carbon footprint
- Longer installed lifetime of copper-alloy mesh (five-plus years vs. three months for synthetic material), resulting in reduced energy consumption and maintenance activities
- Copper-alloy mesh provides a healthier environment for fish, leading to shorter harvest cycles and associated carbon-intensive supporting activities
- Copper-alloy mesh is 100 percent recyclable, resulting in a much more favorable life cycle assessment (LCA) vs. competing technologies
- Improves fish health and production
- Copper-alloy mesh naturally improves water flow and circulation and helps maintain higher oxygen levels that inhibit parasites and pathogens from growing and infecting fish. This reduces the need for added antibiotics and anti-fouling chemicals. Feeding costs can be reduced by 15%.
- Maintains cage volumes
- Clean copper-alloy mesh allows pens to maintain their shape against strong ocean waves and currents, even those offshore. Larger, more stable pen volumes prevent fish crowding and help maintain high oxygenation that ultimately improve yields. The mesh also possesses high mechanical strength and formability, which is essential in the creation of effective marine aquaculture containment structures.
- Excludes predators and prevents escapes
- High-strength copper alloy mesh resists predator attacks, thereby reducing escapes of farmed fish.
- Reduces maintenance
- Copper-alloy mesh rarely needs to be cleaned, lowering overall costs associated with maintenance and diver risk.
- Copper-alloy mesh lasts for six years or more depending on application conditions. Due to its protective patina (coating), it loses little mass over time, and is fully recyclable. Recycled material is used in initial production of copper-alloy mesh, which further reduces CO² emissions, compared with traditional polymer nets. High-strength and corrosion-resistant copper-alloy meshes are compatible with pens commonly used in the marine aquaculture industry, allowing for rapid implementation at existing cultivation centers.