Gilthead sea bream are being increasingly farmed in recirculating aquaculture systems (RAS), which offer precise environmental control. This shift brings both welfare improvements and new challenges.
RAS technology represents a genuine welfare improvement for sea bream farming in several dimensions: elimination of storm and predator risk, precise water quality management, and removal of sea lice. However, high stocking densities in some RAS operations recreate the crowding stress of open systems. Aggression between sea bream at feeding is a persistent welfare challenge. Lighting schedules in RAS can be optimized to reduce aggressive encounters and synchronize feeding behavior. The technology also enables faster identification of disease, allowing earlier intervention. As RAS costs fall and welfare science improves, the welfare case for RAS over open-sea net pens strengthens.