Zero-water exchange and biofloc shrimp farming systems aim to improve environmental performance but create specific welfare challenges related to water quality management and crowding.
The welfare implications of zero-water exchange shrimp systems are complex. These systems were developed primarily for environmental reasons, reducing the effluent discharge that makes traditional shrimp farming ecologically damaging. However, the very high stocking densities they enable create significant welfare risks. Shrimp welfare research indicates that crowding causes chronic stress responses that impair immune function and growth. Oxygen management failures in high-density systems cause acute mass mortality events that represent catastrophic welfare failures. The environmental benefits of improved water management should not be pursued at the cost of welfare standards that require evidence-based stocking density limits.