Effects of Pumping Height and Repeated Pumping in Atlantic Salmon <i>Salmo salar</i>

Abstract

The aim of this study was to evaluate the effects of pumping height and repeated pumping on the generalized stress response and gross injuries in harvest sized Atlantic salmon. Fish pumped from a net pen at either high (5.2 m) or low (3.6 m) pumping heights showed an elevated, but not severe physiological stress response (pH, pCO 2 , lactate, potassium, haematocrit, and sodium) compared to fish netted (not pumped), while effects of different pumping heights were overall not demonstrated. Repeated pumping (either 3 or 6 times) also caused an increase in stress response (pH, pCO 2 , pO 2 , lactate, potassium and sodium) compared to control fish, and a positive dose-response relationship was found for lactate. No fish died as a result of pumping, nor were injuries observed that could exclusively be attributed to pumping. In conclusion, although elevated from the control groups, the stress response following increasing pumping height and repeated pumping as conducted in these experiments were not indicative of causing severe stress or injuries.

Effect of handling and crowding on the susceptibility of Atlantic salmon (Salmo salar L.) to Lepeophtheirus salmonis (Krøyer) copepodids

“…Those include delousing treatments such as freshwater bathing, mechanical removal, thermal treatments and laser delousing (Overton et al., 2018). Mechanical and thermal delousing (using cold or warm water) typically involves some pumping and crowding prior to the treatments, which can themselves damage the skin and the mucus layer, leading to significant physical stress (Espmark et al., 2016; Gismervik et al., 2019; Overton et al., 2019).…”