European perch is emerging as an important species in recirculating aquaculture systems in Northern Europe. Understanding and managing welfare challenges is essential for sustainable expansion.
As perch aquaculture expands in indoor RAS facilities, welfare challenges become apparent at high densities. Dominant fish suppress subordinate feeding, causing size variation and chronic stress in smaller individuals. Providing physical complexity through shelter structures, maintaining optimal photoperiod and temperature, and avoiding abrupt environmental changes substantially improves welfare and production performance.