Fish Welfare Indicators: Assessing Wellbeing in Aquatic Animals

Developing reliable welfare indicators for fish is a scientific priority, enabling evidence-based assessment and improvement of conditions in aquaculture and research settings.

Key Facts

Fish welfare indicators include physiological, behavioural and external lesion-based measures
Cortisol levels, glucose responses and immune parameters provide physiological welfare information
Behavioural indicators include shoaling patterns, surface breathing, startle responses and feeding motivation
External indicators include fin damage, lesions, cataracts and gill condition visible during inspection
The Welfare Quality for Fish framework adapts terrestrial welfare assessment principles to aquatic species
Operational welfare indicators usable in farm conditions are critical for practical welfare improvement

Welfare Considerations

Assessing fish welfare is complex because fish cannot report their experiences verbally and many welfare-relevant states are not easily visible. Scientific progress in developing validated, practical welfare indicators has accelerated significantly since 2010. Robust indicators that can be used routinely by farm staff — not just in research settings — are essential for translating welfare science into improved everyday fish welfare outcomes.

What You Can Do

Support certification schemes that use validated welfare indicators for farmed fish
Advocate for mandatory welfare assessment requirements in aquaculture licensing
Encourage retailers to require supplier reporting against established fish welfare indicators
Support research institutions developing species-specific fish welfare assessment tools
Follow and share updates from organisations like the Fish Welfare Initiative