As the demand for seafood continues to grow, the aquaculture industry is under pressure to come up with sustainable and efficient ways to produce high-quality seafood products while minimizing their environmental impact. In this regard, recirculating aquaculture systems (RAS) have emerged as an innovative technology offering a sustainable seafood production approach.
RAS provides a carefully controlled indoor environment that produces high-quality seafood while minimizing reliance on wild-caught fish. One of the most critical factors in RAS production is the selection of appropriate species. Let’s explore a few points to consider when selecting suitable species for commercial production in RAS systems, including the market outlook.
Popular Species for RAS and Their Market Outlook
Salmon
Salmon is one of the most popular fish produced in RAS systems, with a promising market outlook. The demand for salmon is on the rise, and RAS technology enables the production of high-quality salmon while minimizing the impact on the environment. Salmon is loved for its high nutrient density and omega-3 content, as well as its versatility in many recipes, driving a rapidly increasing demand. The global salmon market is estimated to reach $76,145.3 million by 2028, registering a CAGR of 3.7% from 2021 to 2028.
Tilapia
Tilapia is another popular species for RAS production. This fish is easy to grow in RAS and is noted for its mild flavor and health benefits. It is highly versatile and can be used as an alternative to salmon in some recipes. According to Allied Market Research, “Tilapia is an inexpensive fish with good taste, so it substitutes the expensive seafood and all these factors along, lead to its growth all over the globe.”
Barramundi
Barramundi, also known as Asian sea bass or giant sea perch, is another species grown in RAS that has become popular recently. This fish is noted for its mild flavor, high nutrient content, and excellent texture. It can be used in a variety of recipes and is becoming increasingly popular as an alternative to salmon or tilapia. The overall global sea bass market size was $3.5 billion in 2020, and is projected to reach $7.9 billion by 2030, registering a CAGR of 6.8% from 2021 to 2030.
Shrimp
Shrimp is a popular seafood option for RAS farming due to its high market value. In addition, RAS technology allows for greater control of water quality, which improves shrimp growth rates and overall health. Fresh shrimp are used in many cuisines, especially Asian and Latin American, where they are often stir-fried, grilled, or used in soups and stews. With the growing popularity of shrimp dishes and their rich nutritional profile and associated health benefits, very strong growth is expected. The shrimp market size was valued at $31.6 billion in 2019, and is estimated to reach $54.6 billion by 2027, registering a CAGR of 9.2% from 2021 to 2027.
Creating an Optimal Growth Environment for Seafood with RAS
RAS systems allow growers to create an optimal growth environment for their chosen species through tight control of water temperature, pH levels, dissolved oxygen levels, and nutrient concentrations. RAS allows for a significantly higher fish density than traditional aquaculture systems. This higher density does not affect the optimal growth levels of the fish as the water quality is kept at a high level.
For instance, trout thrive in low temperatures of between 52°F - 65°F and prefer high dissolved oxygen levels. A RAS system allows for precise control of these parameters, which helps create the optimal growth environment for trout. Moreover, to maintain a healthy environment, it’s essential to ensure the water flows smoothly without any significant pressure changes, which can be achieved through careful consideration of the design and equipment selection for the RAS systems.
In contrast, shrimp require exceptional water quality characterized by low levels of organic matter, ammonia, and nitrite, as well as moderated calcium and magnesium levels. Shrimp farmers carefully monitor stocking densities to maintain an ideal growth environment. Moreover, they must prioritize water filtration, particularly biofilters, to sustain optimal shrimp growth.
Special Considerations for RAS Production
While RAS systems have many advantages, certain species with unique environmental needs may require specialized adjustments. For instance, yellow perch require dim light and minimum noise exposure, which can be hindered in a commercial RAS setting. Growers must manage the facility to limit unwanted light penetration, minimize noise, and optimize feeding patterns to reduce disturbance.
Another consideration is the specific water requirements of the chosen species. For example, certain fish may require water that is low in hardness, high in dissolved oxygen, naturally acidic, or brackish. Sturgeon requires freshwater with neutral pH for the best growth rates, while some species of tilapia or catfish prefer a more acidic environment.
Finally, when selecting a species for RAS culture, understanding and considering their life cycles can help optimize production and reduce costs. For example, most common species used for production have a two to three years life cycle. Thus, the number of fry that are stocked must be high enough to maintain populations in each tank throughout the total culture period. By understanding the life cycles and production needs of different fish species, growers can make more informed decisions when selecting a species for RAS culture.
Selecting a suitable species is vital in any aquaculture venture, and RAS systems are no exception. Therefore, it is crucial to identify a species well adapted to RAS systems’ unique attributes, ensuring optimal growth and overall efficiency. RAS systems provide aquaculture producers with more efficient and sustainable ways of cultivation while reducing environmental impact. The attention to detail on the individual species’ ecological conditions and needs in this system is a crucial determinant of success. As the technology matures, the number of aquaculture species suited to RAS systems is expected to grow.
