Stocking density is a critical welfare determinant in farmed shrimp. Overcrowding increases aggression, disease susceptibility, and mortality while compromising water quality and individual behavioural needs.
The welfare of farmed shrimp sits at the boundary of scientific consensus and ethical uncertainty. Evidence for nociception and stress responses in shrimp is accumulating, making the dismissal of their welfare increasingly untenable. At high densities, shrimp exhibit physiological indicators of chronic stress, show increased disease susceptibility, and engage in destructive competitive behaviours including appendage damage through aggression. Water quality deterioration at high densities compounds stress through hypoxia and ammonia toxicity. The welfare-positive response does not require certainty about shrimp sentience — a precautionary approach recommending lower stocking densities, better water management, and welfare-oriented slaughter methods is proportionate to the evidence.