A recent in-depth study has examined farmed fish welfare within the European Union, focusing on five key fish species: European sea bass, gilthead sea bream, rainbow trout, common carp, and Atlantic salmon.
The investigation, led by Professor Michail Pavlidis of the University of Crete, was requested by the European Parliament’s Committee on Fisheries. The researchers used a variety of research methods, including consultations with stakeholders and case studies, to shed light on fish welfare requirements.
The researchers also analysed the farming practices employed in the cultivation of the five different species, and areas of concern pertaining to farmed fish welfare across various production systems and life stages.
No “one size fits all” approach to farmed fish welfare
The researchers found that all fish species share common welfare needs, encompassing aspects such as sufficient nutrition, appropriate water quality, optimal health and fitness, freedom to exhibit natural behaviors, and safety.
However, due to variations in stress response and behaviours associated with survival and reproduction among different species and individual fish within a population, specialized research is necessary for each farmed species. For example, rainbow trout, the most frequently-raised fish in inland aquaculture, is considered a “stress-sensitive” species in comparison to other aquaculture species farmed in the EU.
The study identified four major challenges to ensure farmed fish welfare: firstly, the need to balance scientific knowledge with ethical considerations in determining approaches to fish welfare, secondly, how to identify species-specific welfare requirements, thirdly, methods of accurately assessing of fish welfare directly at the farming sites; and lastly, the necessity of establishing a suitable regulatory framework for farmed fish welfare in the EU.
Welfare during grow-out phase affected by a wide variety of factors
The researchers identified several welfare concerns during the grow-out phase of fish farming each of the species. Water quality and potential shortages, together with imbalances in water temperatures and oxygen levels, are key to welfare, the authors note.
In addition, inadequate availability of specialized vaccines and approved anesthetics, insufficient environmental control and weak biosecurity measures all negatively impact fish welfare.
Fish welfare could also be negatively impacted by inappropriate stocking densities, intense handling practices, transportation and harvesting of live fish, and a lack of on-site welfare monitoring tools, among other factors.
The need for better staff training and continuing professional development on fish welfare was also highlighted as an area requiring action at EU level.
Regulations needed to guide industry on farmed fish welfare, research says
At present, the existing legislative framework within the EU does not impose specific welfare requirements directly on farmed fish. The study proposes that updated legislation should incorporate fundamental goals and general principles for fish welfare, establish enforcement mechanisms, and create a framework for developing legislation on specific areas such as handling, live transportation, and slaughter.
The authors highlight the mounting societal and political concerns surrounding fish welfare and its vital role in sustainable aquaculture. Further investigation into the impact of routine production operations and management practices on fish welfare is needed, they argue, with too little still known about the interconnections between stress, disease resistance, and the welfare of farmed fish.