Some fish stunning and killing related factors could increase risk of microbial contamination
The European Food Safety Authority (EFSA) asked its Panel on Biological Hazards to deliver a scientific opinion on: Food Safety considerations concerning the species-specific welfare aspects of the main systems of stunning and killing of farmed fish. The Animal Health and Welfare Panel (AHAW) has addressed animal welfare aspects of the main systems for stunning and killing for eight fish species in form of seven separate scientific opinions. In this opinion, the BIOHAZ Panel has focused on the food safety relevance of the stunning and killing factors relating to fish welfare, in a single opinion. Safety of farmed fish and fish products is influenced by farming conditions, pre-slaughtering practices and stunning/killing operations. A former BIOHAZ opinion concluded that fish farmed in Europe have a good record of safety with respect to biological hazards, and that the food safety risk associated with aquaculture products is very low. Post-slaughtering and processing stages have not been considered in this opinion, but they also exert an important influence on the safety of fish and fish products. In this opinion, only biological risks have been assessed.
It is generally considered that use of farming systems based on good hygienic practices including provision of optimal animal welfare increases the animals’ resistance to infections and leads to a reduction of the food safety risks associated with the resulting foods of animal origin. In other words, in principle, on-farm animal welfare assurance contributes to the resulting food safety assurance. After slaughtering the biochemistry of the muscle post-mortem is influenced by the method used in pre-slaughter handling and stunning/killing of fish and this may have an influence on the microflora. It is also well known for other animal species that any slaughter-related operation that involve penetration of the skin, such as stunning with captive bolt or exsanguinations, carry a risk of introducing pathogenic bacteria from the skin onto/into edible parts of the animal directly or via blood circulation.
The Scientific Panel on Biological Hazards concludes that: based on general principles of food hygiene, some fish stunning & killing related factors (e.g. microbial contamination of water, increased handling, invasive stunning and exsanguination methods) could lead to increasing the risk of microbial contamination of fish. As the scientific information on specific welfare hazards of the stunning and killing practices that could compromise safety of fish products is very limited, a definitive assessment of the food safety risks associated with different stunning and killing methods for fish is not possible at this time. Measures intended to preserve fish welfare by avoiding stress during stunning & killing and improving environmental conditions, are expected to have a positive impact on the safety of the food product.
In order to further address the relationship between stunning and killing practices affecting welfare and any food safety hazards, further coordinated research is necessary.
Food Safety considerations concerning the species-specific welfare aspects of the main systems of stunning and killing of farmed fish
(Question number: EFSA-Q-2008-770) Opinion (PDF)
