Course

Animal welfare is a complex, multi-faceted subject and there are still ongoing discussions among researchers, scientists and other actors working on how to best define welfare, to provide a more balanced/universal mental framework. How welfare is defined and conceptualized in research and project work determines largely how welfare is then assessed and influenced, thereby making this a crucial first step.

Any farmed aquatic animal is required to be reared in conditions that present as many positive experiences as possible over the course of its life history, that would translate to a "good" welfare status. This welfare status, however, is dynamic and depends on both internal factors of the animal and external factors surrounding the animal that are explored in this section

Animal welfare status can be assessed based on the five domains which are also applied to aquatic farmed animals. Expressed in terms of compromises, they address more practically where issues arise with animal welfare. This section explores each of the five domains, and how they interact with each other to help form a larger understanding for what matters in animal welfare.

An important consideration in animal welfare is determining the point at which unpleasant states are deemed to be significant enough to negatively impact an animal's welfare status. This section explores the distinction that must be attempted to be made between unpleasant stressors and suffering that definitively causes suffering and a compromise to animal welfare.

Due to the complexity of animal welfare, and the previously mentioned importance of clearly defining animal welfare terminology, it is vital that working definitions be outlined for the most relevant terms surrounding this topic.

When the nervous system of a species attains a certain level of complexity during its evolution, it is assumed that animals are able to develop the first basis of consciousness, forming and acting upon internal (neural) representations of their environment for the purpose of directing the animal's behaviour.

Understanding the differences between pain perception and nociception is a helpful way of putting into practice the different definitions of animal welfare that were outlined in the beginning of this module.  This section explores how these two mental processes are different, and why this distinction is significant to aquatic animal welfare.

The vast diversity of farmed aquatic species prevents this course from covering species-specific welfare requirements in great detail for each species of interest. Regardless of the species being farmed, however, several key factors remain central to all fish farming practices. A high-level overview of the various aspects of aquaculture that can potentially influence fish welfare are outlined in the next few sections.

Aquatic animals are subjected to a range of different husbandry routines and operations throughout their respective production stages. The stressors caused by these operations, while in many cases unavoidable, can also in many cases be reduced. Since stress can not only impact welfare but production and survivability, there are both economic and welfare related motivations for ensuring that the frequency and effects on a number of key management practices are minimised. Conversely, certain practices (particularly enrichment) can have a positive effect on welfare.

Two of the main areas for technology development that have driven much of the expansion of aquaculture around the world are firstly the closing of the production cycle. This has been achieved though management and spawning of broodstock, the collection and hatching of eggs, and the rearing and weaning of offpring. Each of these stages require separate consideration of welfare needs. Furthermore, the use of hatcheries has enabled selective breeding programmes which are altering the characteristics of the farmed animals. The second area for development has been in the field of nutrition, and particularly the formulation of suitable compounded diets for many species. These potentially resolve some welfare issues, but also raise new ones. 

In general, the more intensive the aquaculture system, the greater the requirement for managment interventions which involve doing things to the stock. For example, moving them from one rearing enclosure to another, grading them by size or even transporting them between farms and ultimately to market.

For the purposes of this course, interventions are considered to be direct actions on the stock, usually involving handling in some way, for the purposes of managing health, or for slaghter at the end of the rearing period

Environmental factors play a critical role in determining the welfare of farmed aquatic animals. These factors can largely be grouped into two categories - biotic factors and abiotic factors. Understanding these categories and their interplay is essential to informing on targeted strategies and research work to optimise aquatic animal welfare and address the challenges posed by the environment effectively.
This section considers the main biotic factors, which are those relating to living organisms such as pathogens, predators, and other species/conspecifics. Biotic factors tend to govern the interactions with living organisms that are relevant to farmed aquatic animal welfare (e.g., disease dynamics and social behaviours).

This section considers the abiotic factors, which are non-living elements such as water quality, temperature and oxygen levels. Abiotic factors primarily shape the physical conditions of the habitat involved (e.g., water quality and enrichment).

To assess an animal's welfare, a range of welfare indicators (WIs) must be established. WIs provide some form of quantitative or qualitative information on different aspects of the animals' welfare. As outlined in module 2, many welfare factors / challenges are applicable to all rearing systems. Likewise, there are certain WIs that can be used in most, if not all, rearing systems. Conversely, certain WIs are very specific to a production system or set of systems.

Animal-based WIs are outcome-based, reflecting an animal's current welfare status by capturing past changes. This section focuses on WIs that directly assess their physical health, outlining their relevance to specific welfare aspects and key sampling considerations. These indicators are either scored qualitatively using a rank-based system (often morphological OWIs), or on continuous scales (often physiological OWIs).

Welfare indicators (WIs) not only vary in practicality and labour intensity but also impact animal welfare differently. Some, like physiological sampling or handling outside of water, can be invasive and disruptive, while others allow assessment with minimal disturbance. Another key factor is personnel involvement—direct animal-based WIs often require multiple farm staff, whereas remote sensing and automation can eliminate the need for on-site personnel. This section explores indicators that are non-invasive, some of which can be carried out remotely and even automated.

Risk-based indicators compliment animal-based indicators in that they are concerned with identifying and reducing factors which might compromise the welfare of the stock. They can be used to help design better farming systems, improve welfare monitoring and are particularly used in farm certification programmes.

Aquatic animal welfare is heavily influenced by environmental conditions, with water quality parameters playing a complex but crucial role. The importance of environmental indicators lies in their associated factors directly impacting the physical health of aquatic animals in a myriad of ways. This section focuses primarily on environment-based OWIs, emphasizing the practical and logistical considerations in sampling them.

This module provides a framework for developing and conducting a welfare assessment scheme (WAS). This includes criteria for selecting appropriate OWIs, comparing scoring systems under different contexts, and key considerations for interpreting results from OWIs collectively and reaching a conclusion on a WAS.

This section provides two case studies of approaches used in welfare assessment schemes (WASs), briefly comparing them and how they differ by their underlying purposes and considering their pros and cons. This allows further examination of what OWIs are included in the WAS, and why/how; The structure of the WAS, such as how OWIs are being used together / categorised; and whether a scoring system is included, and if so, why/how.

As demand for improving farmed aquatic animal welfare grows, so will the need for transparency, assurances, and certifications from aquaculture sectors hoping to participate within the global market. This module will explore the current gaps, logistical challenges, and technical limitations that currently face on-farm welfare assessments. In relation to this, we will investigate the most promising areas for research and how these may intersect with emerging technologies. Finally, we highlight the importance of engaging with stakeholders, and how they can help ensure advancements in farmed aquatic animal welfare are impactful and sustainable.

At present, there are a limited number of practical OWIs that directly assess (or attempt to assess) the animals' emotional states. Approaches such as Behavioural OWIs or QBA are promising, but face technical and logistical challenges. This section will outline these hurdles and the unique difficulties they present in the aquatic environment.

The lack of efficient on-site data collection limits farm management responses. To address this, aquaculture is adopting precision farming with automated, real-time monitoring. Since behavioural assessments often rely on visual observations, emerging technologies integrating with video surveillance could significantly enhance welfare assessments. This section will explore how these innovations overcome logistical challenges and improve behavioural evaluation.

Advancements in digital technology and automation are transforming the way behavioural welfare indicators (WIs) are assessed on farms. From smartphone applications simplifying real-time behavioural scoring to emerging tools for automated data processing and statistical analysis, these innovations are making welfare assessments more efficient and less labour-intensive. As machine learning and computer vision continue to evolve, the potential for fully automated behavioural assessments, including Qualitative Behavioural Assessment (QBA), is becoming increasingly feasible. This section explores how these technologies are shaping the future of animal welfare monitoring.

As aquaculture continues to intensify and progress further into the realm of big data, the sector's reliance on emerging technologies to capture, record, and analyse data will become more and more commonplace. However, how this is managed and the role of different actors throughout the value chain will also be important. This section will explore crucial areas of social studies that remain overlooked for many aquaculture regions.

This course has provided a comprehensive exploration of farmed animal welfare, with a particular focus on the unique challenges posed by aquatic environments. By examining welfare principles, assessment methods, and emerging innovations, you have gained valuable insights into how welfare can be integrated into aquaculture practices. As the field progresses, collaboration between industry and academia, along with advancements in technology and policy engagement, will be essential for ensuring meaningful and practical welfare improvements. This section will preview the key considerations for moving forward in this evolving discipline.