Abstract
Simple SummarySea cage farms dominate European aquaculture production of seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata). It means that to complete the commercialization process, fish must be crowded in a net, lifted from the rearing cage, and placed in a stunning/slaughtering tank during the extraction procedure. Brailing and pumping are the two techniques used. The brailing involves the use of a large net that is hoisted by a crane, and the fish and water are released from the brail by opening the closed end of the net with a release. The fish enter water through a pipe and pass through a grid that removes the water before being placed in the stunning/slaughtering tank. This paper examines the scientific progress made in these areas over the last two decades in relation to farmed seabass and seabream describing the consequences of different methodologies on the time fish takes to reach the unconscious stage, the different concentrations of stress indicators in plasma, and the evolution of flesh quality related to spoilage during fish shelf-life.The behavioural responses of fish to a stressful situation must be considered an adverse reaction caused by the perception of pain. Consequently, the handling prior to stunning and the immediacy of loss consciousness following stunning are the aspects to take into account during the slaughtering process. The most common commercial stunning method in seabream and seabass is based on hypothermia, but other methods such as electrical stunning, carbon dioxide narcosis or anaesthetic with clove oil, are discussed in relation to the time to reach the unconsciousness stage and some welfare indicators. Although seawater plus ice slurry is currently accepted in some guidelines of fish welfare well practices at slaughter, it cannot be considered completely adequate due to the deferred speed at which cause loss of consciousness. New methods of incorporating some kind of anaesthetic in the stunning tank could be a solution to minimize the impact on the welfare of seabass and seabream at slaughtering.
Highlights
Animal welfare evaluation should be promoted so that decisions are made based on scientific evidence rather than emotion, with the understanding that the concept of welfare is a characteristic of an animal, not something given to it, and can be precisely measured [1]
Taking into consideration that the total aquaculture production of seabass and seabream increased from just under 8 thousand tons in 1990 to 522 thousand tons in 2019 [18], it seems pertinent to discuss the scientific evidence on slaughter methodologies to try to guarantee the best welfare conditions for both species
A multidisciplinary approach that considers animal behaviour as well as the various biochemical and physiological ante mortem and post-mortem processes could be the best strategy for determining fish welfare during stunning/slaughtering procedures and their impact on product quality [24]
Summary
Animal welfare evaluation should be promoted so that decisions are made based on scientific evidence rather than emotion, with the understanding that the concept of welfare is a characteristic of an animal, not something given to it, and can be precisely measured [1]. Fish may not have the complex brains of the higher mammals, but they do have a nervous system that can detect noxious stimulation Such an experience does not need a cortex because the experience is raw, tied directly to the immediate damage, and is an objective extension of that damage, which drives the aversive behavioural responses [7,8]. Despite the fact that fishes are very different from us and are unlikely to have a capacity for awareness of pain or emotional feelings that meaningfully resemble our own [15], a strong alternative view is that complex animals with sophisticated behaviour probably have the capacity for suffering, though it may differ in degree and kind from the human experience [16]. Taking into consideration that the total aquaculture production of seabass and seabream increased from just under 8 thousand tons in 1990 to 522 thousand tons in 2019 [18], it seems pertinent to discuss the scientific evidence on slaughter methodologies to try to guarantee the best welfare conditions for both species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
