European sea bass and striped bass are increasingly farmed in recirculating aquaculture systems (RAS). These closed systems offer welfare advantages but also introduce unique stressors.
RAS aquaculture represents both an opportunity and a challenge for fish welfare. The controlled environment allows precise management of temperature, oxygen, and ammonia — key welfare parameters — eliminating the seasonal and weather-related stressors of outdoor systems. However, RAS typically involves higher stocking densities, constant low-level noise from pumps and filters, and artificial lighting regimes that may not suit fish behavioral needs. Bass are active, territorial species that benefit from structural complexity even at high densities. The risk of catastrophic system failure causing rapid suffering and mortality is a significant welfare concern requiring robust backup systems and monitoring. Overall, well-managed RAS can offer superior welfare compared to poorly managed sea cage systems.