The welfare of farmed fish has become an urgent concern. A comprehensive understanding of fish behavior and their interactions with specific aquaculture environments is crucial for ensuring their welfare.
To address this issue, the Fair-Fish database has developed a valuable tool: the WelfareCheck profiles. These profiles provide a standardized assessment of the welfare of various farmed aquatic species, focusing on key behavioral indicators. These indicators encompass aspects such as distribution area, depth area, migration patterns, reproduction, aggregation patterns, aggressive behavior, substrate needs, stress responses, malformations, and slaughter protocols.
A recent study published by researchers from the FishEthoGroup Association, Alianima, CAUNESP—Centro de Aquicultura da UNESP, and the Centre of Marine Sciences (CCMAR/CIMAR-LA) analyzed the WelfareCheck profiles to identify the most important criteria for fish welfare.
Welfare of Farmed Fish
Fish are sentient beings capable of feeling pain and suffering, and many face challenges that may compromise their welfare. These challenges include limited space, unnatural social groupings, sterile environments, and various stressors.
Moreover, unlike terrestrial farming, which focuses on a handful of species, aquaculture involves hundreds of them, each with unique needs. This diversity presents a significant challenge: we lack sufficient knowledge about the welfare of many farmed fish species.
Assessing Fish Welfare: Different Approaches
There are three main approaches to assess fish welfare:
- Function-Based: This approach focuses on biological functions, such as growth, feeding, and disease resistance. It relies on measurements such as hormones, metabolism, and immune indicators.
- Nature-Based: This approach assumes that fish perform better when they can exhibit natural behaviors, such as social interactions, courtship, and predator avoidance. Researchers observe and analyze these behaviors to understand fish welfare.
- Feeling-Based: This approach recognizes fish as sentient beings with emotional states. While directly measuring emotions is challenging, scientists use behavioral and neurophysiological indicators to infer emotional states such as fear, stress, and social preferences.
The Fair-Fish Database: A Model of Transparency
The Fair-Fish database is a valuable resource for understanding fish welfare in aquaculture. This open-access platform provides a comprehensive overview of the welfare of farmed aquatic species worldwide.
WelfareCheck Profiles:
The Fair-Fish database offers WelfareCheck profiles for each species. These profiles assess the welfare of fish based on 10 key criteria derived from the scientific literature:
- Distribution area
- Depth area
- Migration patterns
- Reproduction
- Aggregation behavior
- Aggressiveness
- Substrate needs
- Stress responses
- Malformation rates
- Stunning and slaughter protocols
These criteria cover a broad spectrum of factors that may influence fish welfare. Each criterion receives a rating based on:
- Probability: What are the chances that the fish experience good welfare under current farming conditions?
- Potential: What is the welfare potential of these fish under improved farming conditions?
- Certainty: What level of confidence do we have in these assessments based on available scientific data?
The WelfareScore provides a summary of the overall welfare status of a species. It reflects the frequency of “high” ratings across all criteria and dimensions.
Key Findings from the Study
Researchers found that, while there were no significant differences in the probability of the studied species meeting their basic welfare needs, criteria related to reproduction, slaughter practices, and substrate needs showed greater potential for improving welfare outcomes. Additionally, reproduction and migration patterns demonstrated a high level of certainty in the available literature.
Reproduction: A Critical Indicator of Welfare
One of the most important factors influencing fish welfare is their ability to reproduce naturally. The Fair-Fish database found that criteria related to reproduction consistently demonstrated a high potential for achieving better welfare outcomes.
This suggests that by creating aquaculture environments that mimic natural reproductive conditions, we can significantly enhance the quality of life for farmed fish. This could involve factors such as providing suitable spawning areas, ensuring adequate water quality, and allowing fish to exhibit natural mating behaviors.
Addressing Knowledge Gaps
While the database has shed light on the importance of reproduction, it has also highlighted several knowledge gaps that need to be addressed. For example, there is a lack of certainty regarding aggression levels among farmed fish species.
Understanding how fish interact with each other can help prevent stress and improve overall welfare. Furthermore, information on distribution area, aggregation patterns, stress responses, and malformations is often inconsistent or lacking. More research in these areas is essential to develop more accurate assessments and recommendations for the ethical farming of aquatic species.
Conclusion
In conclusion, the WelfareCheck profiles offer a valuable framework for assessing fish welfare in aquaculture. By focusing on key behavioral indicators, these profiles provide a more comprehensive understanding of the needs and behaviors of farmed species. While significant progress has been made in understanding the importance of reproduction for fish welfare, further research is essential to address remaining knowledge gaps and develop more comprehensive strategies to improve their welfare.
The study was funded by FCT—Foundation for Science and Technology.
Reference (open access)
Maia, C. M., J. L. Saraiva, J. L. & Eliane Gonçalves-de-Freitas (2024). Fish welfare in farms: Potential, knowledge gaps and other insights from the fair-fish database. Frontiers in Veterinary Science, 11, 1450087. https://doi.org/10.3389/fvets.2024.1450087
