Pre mortem capturing stress of Atlantic herring (Clupea harengus) in purse seine and subsequent effect on welfare and flesh quality
Peer reviewed, Journal article
MetadataShow full item record
Original versionFisheries Research. 2021, 244 . 10.1016/j.fishres.2021.106124
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.