Pre-harvest crowding of farmed salmon concentrates fish at extreme densities before slaughter, creating a welfare-critical period that can undermine months of good welfare management.
Pre-harvest crowding is a welfare-critical phase because high-density concentration causes acute stress in fish that may already be weakened by end-of-production disease load. Welfare improvements at slaughter can be undermined by poor pre-slaughter management. Farm-to-abattoir welfare continuity is essential.