Antibiotic use in aquaculture relates directly to disease welfare and antimicrobial resistance. Understanding the relationship between welfare standards and antibiotic use guides better practice.
The relationship between aquaculture welfare and antibiotic use is direct: poor welfare conditions create the disease pressure that drives antibiotic use. High stocking densities, poor water quality, inadequate biosecurity, and immunosuppressive stress all increase susceptibility to bacterial and parasitic disease. Improving welfare standards by addressing these root causes reduces disease incidence and consequently antibiotic need — a genuine win-win for animal welfare and public health. The Norwegian salmon industry demonstrates that vaccination combined with welfare improvements can virtually eliminate antibiotic dependence. This model should guide reform across other species and producing countries rather than continued tolerance of high-use systems.