Resumen: Traditional RAS control systems often rely on fixed rules, struggling to meet the dynamic demands of fish at different growth stages. A study published this month in Aquaculture International demonstrates an adaptive AI system capable of “thinking” and “adjusting” like a seasoned aquaculture expert, heralding a transformation in precision farm management.

The Core Challenge: Throughout the 300-day culture cycle of tilapia, the physiological needs and management priorities during the fry, grow-out, and pre-harvest phases are distinctly different. For instance, promoting growth is paramount in the early stage, while maintaining water quality to reduce stress becomes more critical later. A single, fixed control strategy cannot remain optimal across all stages.
The Technological Breakthrough: A Hierarchical Deep Deterministic Policy Gradient (DDPG) Framework
The core of the research team’s solution is a three-tier intelligent architecture:
Lower-level Agents: Specifically control individual operations like feeding rate, aeration rate, and water exchange rate.
Mid-level Policy Library: Three independent optimized strategies are trained for tilapia’s three key growth phases (Days 1-100, 101-200, 201-300).
High-level Meta-Controller: Functions like an experienced farm manager, using real-time monitored data on fish weight and water quality to determine the current growth stage and smoothly blend or switch between strategies.
Verified Results & Professional Insight
The system was validated over 300 days in a commercial RAS facility, significantly outperforming traditional methods:
Notable Economic Benefits: Feed Conversion Ratio (FCR) improved by 18.7%, feed costs were reduced by 18.8%, and final biomass increased by 7.6%.
Exceptional Water Stability: Key water quality parameters like dissolved oxygen and ammonia nitrogen were maintained within the optimal range for 98.3% of the time.

Expert Perspective: The revolutionary aspect of this technology lies in its “explainability.” The system not only makes decisions but also uses “decision trees” and “attention visualization” to show farm operators why a decision was made (e.g., automatically reducing the feeding rate due to a critical ammonia concentration). User studies indicate this significantly increases operator trust in the system and accelerates their grasp of key management principles.
Key Points for Farm Application:
Applicability Assessment: This technology is particularly suitable for species with long culture cycles and distinct stage-specific management needs (e.g., salmon/trout, sea bass, grouper).
Data Preparation: Its implementation requires long-term, accurate historical data on fish growth and water quality to train the AI models.
Phased Implementation: Small and medium-sized farms can start by adopting the concept of “growth-stage differentiated management,” manually setting different water quality and feeding standards for various stages, laying the groundwork for future integration with intelligent systems.
Addressing Transition Pain Points: During growth stage transitions, the system’s adjustment time was shortened by 42.5%, avoiding fish stress caused by drastic environmental fluctuations.

