Stress response according to transport protocol in Norway lobster, Nephrops norvegicus

Abstract

The Norway lobster, Nephrops norvegicus, is a valuable and commonly exported European decapod crustacean, which experiences stress from point of cap- ture and onward transport. Stressors such as air exposure duration (i.e. emersion peri- od) and air temperature have been studied previously. We investigated whether mor- tality could be reduced by decreasing road vibrations during transport, and how physiological stress measurements were influenced in a transport simulation experi- ment, reflecting a typical short road journey along a supply chain. Baseline haemo- lymph samples were taken from lobsters sampled immediately after commercial cap- ture using static traps (lobster pots). Individuals were emersed for one hour, either immobile or with continuous shaking; the latter to simulate conditions occurring dur- ing transport. Both treatments significantly increased Total Haemocyte Counts (THC) and serum glucose, lactate and ammonium concentrations compared to baseline ani- mals. Individuals subjected to continuous shaking showed higher glucose and ammo- nium concentrations compared to individuals maintained immobile. We conclude that shaking appears to influence the physiological responses of N. norvegicus in addition to the effects of emersion alone, and the reduction of road vibrations (e.g. via simple cushioning) can reduce post-transport mortality.