Fish Capture Division, Institute of Marine Research (IMR), Bergen, Norway.
Department of Biological Sciences, University of Bergen, Bergen, Norway.
PLoS One. 2019 Sep 4;14(9):e0222122. doi: 10.1371/journal.pone.0222122. eCollection 2019.
Inducing unconsciousness in fish using electrical stunning prior to slaughter may improve fish welfare and fillet quality if such practises can be disseminated into wild capture fisheries. The objectives of this study were to: 1) evaluate if an established slaughter protocol consisting of dry electrical stunning (using a coupled AC/DC current at ≈ 110 Vrms) followed by chilling could be used to stun the wild captured species Atlantic mackerel (Scomber scombrus) unconscious within 0.5 s; 2) determine if death could be induced without consciousness recovery by longer duration stunning (5 s) combined with chilling in an ice/water slurry for 6 min; and 3) examine the extent of quality defects arising from the applied slaughter protocol. We determined consciousness by examination of behavioural responses in a standardised vitality assessment. Out of a sample of 10 mackerel, 9 were assumed to be rendered unconscious by the 0.5 s stun, as determined by the presence of tonic and/or clonic muscle cramping consistent with a general epileptic insult. Assumed unconsciousness was maintained throughout chilling treatment in all fish (n = 25) following a full stun of 5 s. All fish were assumed to have died as a result of the protocol. There was no evidence of spinal damage or haematoma quality defects post filleting. These results suggest that the examined protocol is effective at slaughtering mackerel in a manner consistent with good welfare and without inducing quality defects, but further research is required to verify the unconscious condition via electroencephalogram (EEG) and before the procedure can be applied in wild capture fisheries.
在宰杀前使用电击使鱼类失去意识，可能会提高鱼类的福利和鱼片质量，如果这些做法能够推广到野生捕捞渔业。本研究的目的是：1）评估一种已建立的宰杀方案，包括干式电击（使用约 110 Vrms 的交流/直流耦合电流），然后进行冷却，是否可以在 0.5 秒内使野生捕获的大西洋鲭鱼（Scomber scombrus）失去意识；2）确定通过更长时间的电击（5 秒）结合冰/水浆中的冷却 6 分钟是否可以在没有意识恢复的情况下诱导死亡；3）检查所应用的宰杀方案引起的质量缺陷的程度。我们通过在标准化活力评估中检查行为反应来确定意识。在 10 条鲭鱼样本中，有 9 条被认为在 0.5 秒的电击下失去了意识，这是通过存在强直性和/或阵挛性肌肉痉挛来确定的，这与全身性癫痫发作一致。在所有鱼（n = 25）中，在进行 5 秒的全电击后，在整个冷却处理过程中都保持了假设的无意识状态。所有鱼都被认为是由于该方案而死亡的。在鱼片切割后没有发现脊柱损伤或血肿质量缺陷的证据。这些结果表明，所检查的方案在宰杀鲭鱼方面是有效的，符合良好福利的要求，并且不会引起质量缺陷，但需要进一步研究通过脑电图（EEG）来验证无意识状态，然后才能将该程序应用于野生捕捞渔业。
