Freshwater perch (Perca fluviatilis) are increasingly farmed in recirculating aquaculture systems. Their specific behavioral needs and welfare management are reviewed here.
Freshwater perch aquaculture in recirculating systems presents welfare challenges centered on the species aggressive nature and cannibalism risk. Juvenile perch at similar sizes will cannibalize smaller individuals — requiring frequent size grading operations that involve handling stress. The balance between reducing cannibalism welfare harm through grading and minimizing handling stress welfare harm is a fundamental management challenge.
Perch social behavior in tanks creates persistent dominance hierarchies where subordinate individuals experience chronic subordination stress. Providing environmental complexity — partial barriers, vegetation, or structural features — reduces direct agonistic encounter rates and improves subordinate fish welfare. Research into perch behavioral needs and enrichment is advancing in RAS-focused European aquaculture institutes.