Tilapia is the third most farmed fish globally and is produced extensively in tropical and subtropical regions with variable welfare standards. Overcrowding, water quality and stocking transitions create the primary welfare challenges.
Tilapia welfare at high stocking densities shows consistent deterioration: fin erosion, increased aggression, elevated cortisol and reduced immune function leading to disease outbreaks. The practice of hormonal sex reversal to produce all-male monosex populations — more economically efficient but involving hormone exposure in early larval development — has received limited welfare assessment despite widespread use. Cage culture in tropical lakes creates environmental challenges including oxygen depletion that directly affects fish welfare. ASC (Aquaculture Stewardship Council) certification for tilapia farms is growing but welfare standards within the scheme are less prescriptive than for salmon.