Tilapia is one of the most widely farmed fish species globally, with welfare challenges related to crowding, water quality, and handling that affect billions of fish annually.
Tilapia dominate global aquaculture for good reasons — they tolerate suboptimal water conditions, grow rapidly, and accept plant-based feeds. But this hardiness has perhaps discouraged welfare scrutiny, as the assumption that tolerant species do not suffer is not scientifically supported. Overcrowded tilapia show fin damage, elevated cortisol, suppressed immune function, and increased disease susceptibility. Male tilapia become highly aggressive during reproductive cycles, causing injury to subordinate fish. Slaughter by ice slurry — the dominant global method — causes prolonged consciousness during the dying process, with tilapia remaining responsive for several minutes in ice. Electrical stunning systems are available and increasingly adopted by welfare-conscious producers but require upfront investment. Better welfare monitoring using color change and behavior scoring tools can be implemented at relatively low cost.