European perch is an increasingly popular aquaculture species in central and northern Europe, with welfare considerations around cannibalism, high-density culture, and slaughter practices.
Cannibalism is the primary welfare concern in perch aquaculture, with larger individuals attacking and consuming smaller conspecifics. Size-grading to separate animals of similar sizes reduces but does not eliminate cannibalism, and grading itself causes acute handling stress. The predatory nature of perch means that injuries from attacks, including fin erosion, eye damage, and scale loss, are common in intensive systems. Water quality management in intensive systems is challenging, and suboptimal oxygen or ammonia levels cause respiratory stress. Slaughter methods in perch aquaculture are poorly documented in welfare terms.