Abalone Welfare in Aquaculture

Key Welfare Considerations

• Abalone are gastropod molluscs with distributed nervous systems; evidence of nociception and stress responses is accumulating.
• Haliotis midae (South African abalone) and H. rufescens (red abalone) are key aquaculture species.
• Abalone welfare concerns centre on water quality, stocking density, handling, and slaughter methods.
• Optimal water temperature ranges vary by species; thermal stress impairs feeding and growth welfare.
• Withering syndrome caused by Candidatus Xenohaliotis californiensis bacteria causes significant welfare impairment.
• Herpesvirus infections cause mass mortality events with associated welfare concerns for affected individuals.
• Stocking density affects feed access, growth uniformity, and aggression welfare indicators in abalone.
• Water quality parameters including dissolved oxygen, pH, and salinity require careful management for welfare.
• Abalone respond to harmful stimuli with defensive withdrawal behaviour, indicating basic nociceptive capacity.
• Handling stress during grading and sorting causes physiological changes including haemocyte count alterations.
• Pre-slaughter welfare options are limited but include cold water anaesthesia and rapid mechanical methods.
• Boiling alive or desiccation are welfare-poor slaughter methods increasingly scrutinised by welfare scientists.
• The moral status of molluscs is debated but precautionary welfare consideration is increasingly advocated.
• Research into abalone consciousness and pain capacity should guide welfare standard development.
• Certification schemes for abalone aquaculture are beginning to incorporate basic welfare criteria.