Atlantic herring was commercially captured with purse seine in catches of 100–400 Mt. During crowding 0–30 min individual fish were sampled from the purse seine, killed by a percussive blow to the head and blood lactate was measured. Muscle pH and rigor index was measured over 24 h. Additionally, 100 fish sampled before and after crowding were stored in tanks, filleted, and analyzed for flesh quality (texture, gaping, blood content, colour and appearance), prior to and after freezing and thawing. Results show that the pre mortem stress associated with capture caused anaerobic muscle activity and the formation of lactic acid both in muscle and blood, elevating with crowding duration. The onset of rigor mortis accelerated with increasing crowding duration. Crowding in the purse seine did lead to lower quality scores of the fillets as seen in softer texture, increased blood content and gaping. Except for blood content, freezing and thawing amplified all measured quality parameters related to the level of stress. We conclude that stress associated with capture and duration of crowding affect the animal’s welfare and will have negative effect on the fillet quality of herring.

大西洋鲱鱼被商业用围网捕获，捕获量为 100-400 公吨。在拥挤期间 0-30 分钟从围网中采集个体鱼，用头部敲击杀死，并测量血乳酸。在 24 小时内测量肌肉 pH 值和僵硬指数。此外，在冷冻和解冻之前和之后，将 100 条鱼在拥挤前后取样储存在鱼缸中，切片，并分析肉质（质地、裂口、血液含量、颜色和外观）。结果表明，与捕获相关的死前压力导致无氧肌肉活动以及肌肉和血液中乳酸的形成，并随着拥挤时间的延长而升高。随着拥挤持续时间的增加，尸僵的发生加速。围网中的拥挤确实导致鱼片质量评分降低，如质地更软、血含量增加和裂口。除了血液含量外，冷冻和解冻放大了所有与压力水平相关的质量参数。我们得出结论，与捕获和拥挤持续时间相关的压力会影响动物的福利，并对鲱鱼的鱼片质量产生负面影响。