The Importance of Shrimp Nurseries in Modern Aquaculture

Shrimp nurseries play a vital role in advancing the shrimp farming industry. Properly designed and managed shrimp nursery systems provide a controlled environment for post-larvae (PL) to grow into strong, healthy juveniles, ready for transfer to grow-out ponds. These systems are not only high in biosecurity but also allow for intensive production of shrimp with sizes ranging from 2 mg to up to 3 grams. This article explores the benefits, design considerations, and key aspects of shrimp nursery systems, underlining their significant contribution to shrimp farming aquaculture.

Benefits of Shrimp Nursery Systems

Shrimp nursery systems offer numerous benefits that enhance shrimp farming efficiency and profitability. Key advantages include:

1. Increased Operational Control and Biosecurity By concentrating shrimp in smaller, intensively stocked units, farmers gain precise control over environmental parameters, water quality, and feed management. This high level of control minimizes risks from pathogens, predators, and competitors. Mechanical, chemical, and biological filtration systems further enhance biosecurity, reducing disease outbreaks and mortality rates.
2. Improved Disease Management Nursery systems contribute significantly to disease management strategies. For instance, larger, more developed shrimp are better equipped to resist diseases like Early Mortality Syndrome (EMS) and White Spot Syndrome Virus (WSSV). Maintaining nursery water temperatures above 30°C can help combat WSSV during colder seasons, while routine monitoring and diagnostic measures can detect infections early, enabling prompt corrective actions.
3. Better Growth Rates and Survival Juveniles raised in nursery systems demonstrate faster growth rates and higher survival percentages. Stocking juveniles instead of PL in grow-out ponds shortens the culture period to market size, allowing multiple production cycles annually. This efficiency translates into higher profits and better utilization of grow-out ponds.
4. Flexibility in Stocking and Seasonal Adaptation Indoor nursery systems enable early stocking during colder months, extending the effective stocking period. For non-integrated farms, nurseries offer the option to purchase seedstock in advance, avoiding peak season costs and uncertainties. Additionally, nursery systems act as acclimation units for farms in low-salinity regions, further enhancing shrimp adaptability.
5. Enhanced Economic Efficiency Despite higher initial investments, the economic returns from nursery systems often outweigh costs. Increased growth rates, higher survival rates, and the ability to harvest more crops annually contribute to improved profitability.

Benefits of Shrimp Nursery Systems

Design Considerations for Shrimp Nurseries

The design and management of shrimp nursery systems are critical to their success. Key considerations include:

Location and Infrastructure

• Proximity to Grow-Out Ponds: Ideally, nurseries should be near grow-out farms for easy transportation and reduced stress on shrimp during transfer.
• Water Source and Drainage: Nurseries should have access to high-quality water, preferably from the farm’s intake canal, and a drainage system separate from the main intake.
• Power Supply: Reliable access to primary and backup power sources is essential to maintain operations.

System Configurations

Nursery systems can be classified into single-phase and multi-phase designs:

• Single-Phase Nurseries: These are designed to stock PL of 2-10 mg and produce juveniles of 0.1-0.3 grams. Tank sizes range from 40 to 200 m³, with densities of 8 to 50 PL/L. Common tank shapes include rectangular, round, and oval raceways.
• Multi-Phase Nurseries: Incorporating a second phase involves stocking 0.1-0.3 g juveniles from the first phase to produce larger shrimp of 1-3 g. These systems are particularly beneficial in regions with seasonal harvesting or where early harvests command higher prices.

Materials and Tank Design

Tanks in shrimp nurseries are constructed from materials like concrete, plastic liners, PVC, or fiberglass. The choice of tank shape impacts efficiency:

• Rectangular Tanks: Easy to build and manage but less effective in removing sludge.
• Round Tanks: Cost-effective and self-cleaning, but space efficiency is lower.
• Oval Raceways: These designs combine efficient water circulation with space utilization, although they require higher energy for water flow.
• Stacked Shallow Raceways: Ideal for maximizing biomass production per square meter, these systems are highly efficient in controlling temperature and feed.

Water Quality Management

Maintaining optimal water quality is vital in shrimp nurseries. Reduced water exchange and higher organic loads necessitate advanced filtration systems and regular monitoring to ensure the health of shrimp and prevent stress-induced diseases.

Design Considerations for Shrimp Nurseries

Hurdles and Mitigation Techniques

While shrimp nursery systems offer numerous benefits, they come with challenges such as:

1. Higher Initial Investments Construction and operational costs for nursery systems exceed those of traditional ponds. Nevertheless, the long-term advantages outweigh the initial costs.
2. Increased Labor and Expertise Requirements Nurseries demand skilled biologists for operation and management. Training staff and maintaining high operational standards are essential.
3. Higher Disease Risks from Increased Stocking Densities Intensive stocking raises organic loads and stress levels, making shrimp more susceptible to diseases. Proper system design and regular monitoring are crucial to mitigate these risks.
4. Stress from Handling and Transfers Frequent handling increases stress levels, potentially affecting shrimp health. Efficient transportation systems and careful management during transfers are necessary.

Real-world Examples and Successful Outcomes

Shrimp nurseries have demonstrated success in regions like Latin America, Vietnam, and Thailand. For instance, in Indonesia, veteran shrimp farmer Hasanuddin Atjo implemented a nursery phase to increase productivity from 71-100 tonnes to 121-140 tonnes per hectare per cycle. By adopting a multi-phase system, Atjo reduced grow-out times and improved survival rates, highlighting the potential of nursery systems in transforming shrimp farming aquaculture.

Future of Shrimp Nursery Technology

With advancements in shrimp nursery technology, these systems are set to become integral to sustainable aquaculture. Innovations like hyper-intensive stacked raceways and improved biofloc systems promise even greater efficiency and environmental sustainability. As more farmers adopt these systems, the shrimp farming industry can achieve higher yields, reduced disease risks, and better profitability.

Future of Shrimp Nursery Technology

Conclusion

Shrimp nursery systems represent a transformative approach in shrimp farming aquaculture. By providing a controlled environment for post-larvae growth, these systems enhance biosecurity, disease management, and economic efficiency. Although initial costs and expertise requirements are higher, the long-term benefits in productivity and profitability make nurseries an invaluable tool for modern shrimp farming. As the industry continues to innovate, shrimp nurseries will undoubtedly play a central role in meeting the growing global demand for sustainable aquaculture.