European perch (Perca fluviatilis) is an emerging aquaculture species in recirculating systems, with welfare challenges related to the species gregarious but aggressive social dynamics and handling sensitivity.
Perch welfare in intensive aquaculture requires understanding of the species social biology. While perch shoal naturally, high stocking densities disrupt social structure and increase aggression. Grading operations cause acute stress and social disruption. As a predatory species, perch in intensive systems cannot express natural hunting behaviour, and feeding enrichment that triggers prey-oriented activity may improve welfare and feed conversion simultaneously. Dissolved oxygen management is critical — perch show rapid stress responses to hypoxic conditions. Developing welfare indicators specific to percid species, rather than applying salmonid frameworks, is an important research priority.