Aquaculture, or fish farming, is essential to the global food system and can be made even better with engineering plastics (1). In 2020, the combined output of fisheries and aquaculture set a record, reaching 236 million tons (2). In 2020, the U.S. aquaculture market was $1.5 billion. Notably, imports comprised up to 85% of U.S. seafood consumption, of which over half was via foreign aquaculture. This demonstrates a high demand for fish and the potential for growth in the domestic aquaculture industry. Often seen as a sustainable protein solution, aquaculture can help ensure a steady seafood supply to meet domestic and international needs (3).
This article explores the sophisticated industry behind aquaculture and recent innovations to enhance efficiency, reduce costs, and maintain sustainability (4). Key to these developments is engineering plastics, which offer solutions to numerous fish farming challenges with durability, resilience, and versatility (5).
Importance of Aquaculture in the United States
The demand for seafood in the United States has grown steadily over the years, with the country relying on imports to meet its demand. Domestic aquaculture production has also grown but has yet to keep up with demand (see growth by proxy via aquaculture additives in Figure 1 [6]). There is an opportunity to decrease reliance on foreign-farmed fish by developing domestic aquaculture. With U.S. population growth, changing dynamics with international trade, and a need to find sustainable protein sources, the role of aquaculture is clear (7, 8).
The nation’s abundant coastlines and freshwater bodies offer an avenue for cultivating diverse aquatic species, from fish to crustaceans. Additionally, significant untapped land could be used for land-based aquaculture. By developing its aquaculture industry, the United States can reduce its reliance on the overburdened wild fisheries while addressing its fish trade deficit (9). From a macroeconomic perspective, the industry’s growth would also create jobs and drive capital back to the United States (7).
How can aquaculture startups succeed? Through innovative designs and the use of modern materials such as engineering plastics.
Role of Engineering Plastics in Aquaculture
Engineering plastics play a transformative role in enhancing the efficiency and sustainability of fish farming systems (4, 10, 11). Materials like high-density polyethylene (HDPE) geomembranes are critical in creating reliable containment systems for fish ponds, effectively controlling seepage, a potential challenge in aquaculture (12, 13). By ensuring better seepage management, these geomembranes enhance the living conditions for aquatic life and lead to significant water conservation (14). Lining systems are essential for effective land-based aquaculture.
| Component | Material | Benefits | Application Example |
| Cages | HDPE | Durability, corrosion resistance, and UV protection. | Marine Donut construction |
| Nets | Thermoplastic nets and Geosynthetics | Less fouling, easy to clean, increased lifespan. | Closed-system fish farming |
| Pipes | PE 100-RC and HDPE pipes | Corrosion-free, shock and UV resistant. | Plumbing systems for fish farms |
| Tanks | Geomembranes and HDPE | Prevents leaks, durable, and UV resistant. | Hatchery tanks, water storage |
| Liners | CPL | Protects against erosion and corrosion. | Pond liners for breeding |
| Floating structures | Thermoplastics | Buoyant, durable, and weather-resistant. | Floating feed systems, cages |
| Sludge collection systems | PE 100-RC and HDPE pipes | Efficient collection, corrosion resistance, long-lasting. | Waste management in fish farms |
| Breeding units | HDPE | Safe environment, prevents external contamination. | Marine Donut |
Concrete protective liners (CPL) are engineering plastics that enhance the performance of concrete structures such as tanks, maximizing the tank’s service life while ensuring a controlled environment for fish (15). This reduces the need for frequent interventions and mitigates water contamination and fish injury. CPLs also play an important role in hybrid systems that raise spawn on land in controlled tanks near the sea before healthy juveniles are transported into floating sea-based systems.
High-density polyethylene (HDPE) pipes have streamlined water transportation in aquaculture systems. Due to their durability, corrosive and chemical resistance, and virtually leak-proof systems, HDPE pipes are ideal for creating robust recirculation systems and other water networks in aquaculture (16, 18). HDPE pipes and other engineering plastics can also be used unconventionally to develop innovative, sustainable aquaculture systems.
The Marine Donut and AGRU Engineering Plastics
The Marine Donut, an avant-garde closed-cage fish farming system, showcases the transformative potential of engineering plastics in contemporary aquaculture (17). Recognized as the world’s largest structure made entirely of thermoplastics, its foundation was fortified with AGRU’s provision of PE 100-RC components, renowned for their resistance against stress cracks, corrosion, and UV damage. These components include pipes with diameters up to 47 inches and sheets of varying thicknesses. The scale of the endeavor was significant, with the usage of several hundred PE sheets.
Architecturally, the Marine Donut is a torus or donut-shaped structure meticulously designed to address some unique challenges in aquaculture, with a closed system minimizing the risk of disease, contamination, algae, sea lice, and escape, thereby optimizing fish welfare. Its geometry and water pressure levels are precisely engineered to ensure optimal fish growth and development.
Spearheading technological advancements, the Marine Donut underwent pilot testing at SINTEF and received exclusive licensing from the Norwegian Directorate of Fisheries for its environmental potential. Comprising an HDPE main structure, it is fortified to act as a protective barrier against external threats, such as lice infestations. From a commercial perspective, it boasts various production strategies, with the capacity to hold up to 1,100 MTB (metric tons of biomass). Advanced features include floating and bracing pipes, ballast tanks for submerging or raising the system, and a waste collection mechanism. Its durability ensures resilience against harsh marine conditions, making it versatile for tropical and temperate waters.
Research indicates that this innovative system can improve fish health, enhance profitability, achieve better feed conversion ratios, maintain superior water quality, reduce mortality rates, and increase fish density. Accordingly, the Marine Donut, backed by AGRU’s robust engineering plastics, stands as a beacon of the future for sustainable and efficient aquaculture.
Summary
Innovations in aquaculture are critical in addressing the global demand for seafood. As natural fisheries face limitations due to overfishing and environmental concerns, aquaculture emerges as a viable, sustainable solution, particularly in the United States, which currently relies on aquaculture imports to meet its demand.
Innovative businesses will be the critical drivers for the domestic aquaculture industry and must utilize the best materials and techniques to create safe, competitive, and cost-effective systems. Engineering plastics have proven beneficial in this domain, offering long-term durability, resilience, and reduced environmental impact. Recent successes demonstrate the potential for these materials to enable whole new approaches to fish farming.
Learn more about AGRU engineering plastics for aquaculture or contact one of our technical experts.
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References
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