Fish Welfare Assessment in Aquaculture Systems

Fish welfare assessment in aquaculture encompasses the evaluation of physiological, behavioural and environmental indicators to ensure the health and well-being of cultured species. Modern frameworks integrate multiple metrics—ranging from growth performance and stress physiology to behavioural patterns—to provide a holistic appraisal of welfare. Key physiological measures include cortisol levels, haematological profiles and immunological markers, while behavioural assessments cover swimming activity, social interactions and preference behaviours. Environmental factors such as water quality, stocking density and enrichment structures are also critical determinants. Advances in sensor technology and data analytics have enabled continuous, non-invasive monitoring of individual and group welfare in real time, facilitating adaptive management practices. These interdisciplinary approaches support sustainable intensification of aquaculture by balancing production objectives with ethical and ecological responsibilities on a global scale.

Research from Nature Portfolio

Recent studies have investigated the impact of dietary composition on gut health and welfare outcomes in marine aquaculture. One investigation evaluated a low-marine-protein diet for European sea bass reared in sea cages, examining growth performance, fillet fatty acid profiles and shifts in gut microbiota. Although growth rates were marginally reduced, welfare indicators such as humoral immunity and overall health metrics remained stable, suggesting that sustainable feed formulations can be implemented without compromising fish welfare. A foundational methodological study introduced a history-based preference index for choice tests in tilapia, enabling quantification of individual environmental preferences over time. This index enhances the resolution of behavioural welfare assessments by distinguishing between transient and consistent preferences, offering a robust tool for enrichment and habitat design in recirculating and pond systems.

Fish Welfare Assessment in Aquaculture Systems publication trend

The graph below shows the total number of articles in fish welfare assessment in aquaculture systems across all publications each year (not limited to Nature Index journals).

Technical terms

Welfare indicators: Quantifiable physiological, behavioural or environmental metrics used to assess the well-being of fish.

Accelerometer tag: A sensor device surgically implanted or externally attached to fish for recording three-axis movement and activity levels.

Telemetry: Remote monitoring technique that transmits sensor data (e.g. movement, physiological signals) from fish to a receiver for welfare evaluation.

References

1. Growth performance, gut microbiota composition, health and welfare of European sea bass (Dicentrarchus labrax) fed an environmentally and economically sustainable low marine protein diet in sea cages. Scientific Reports (2023).
2. A history-based method to estimate animal preference. Scientific Reports (2016).
3. Monitoring welfare indicators of rainbow trout (Oncorhynchus mykiss) in a commercial organic farm: Effects of an innovative diet and accelerometer tag implantation. Aquaculture (2024).
4. Calibrating accelerometer data, as a promising tool for health and welfare monitoring in aquaculture: Case study in European sea bass (Dicentrarchus labrax) in conventional or organic aquaculture. Aquaculture Reports (2021).
5. Fish Welfare in Aquaculture: Physiological and Immunological Activities for Diets, Social and Spatial Stress on Mediterranean Aqua Cultured Species. Fishes (2023).