Aquaculture Europe 2023

September 18 - 21, 2023


Add To Calendar 20/09/2023 14:30:0020/09/2023 14:45:00Europe/ViennaAquaculture Europe 2023EVALUATION OF THE STRESS RESPONSE AT SLAUGHTER IN EUROPEAN SEA BASS Dicentrarhus labraxStrauss 3The European Aquaculture Societywebmaster@aquaeas.orgfalseDD/MM/YYYYaaVZHLXMfzTRLzDrHmAi181982


 J. Arboleda*1, L. Papaharasis2 and M. Pavlidis1


1University of Crete, Department of Biology, GR-70013, P.O. Box 2208, Heraklion, Crete, Greece

2 AVRAMAR,  19,3 km Markopoulou–Paiania Ave.  190 02, Paiania, Greece




 Fish welfare is a major component of sustainable fish farming and  research to gain an in-depth understanding of the factors affecting the welfare of farmed fish is of high priority .  Guidelines  from the World Organisation for Animal Health  and European Food Safety Authority of economically important aquaculture species are available,  including harvest and slaughter,  however, there is  still a  need to develop efficient  humane  slaughter  methods (Hastein, 2007) .  Existing m ethods for European sea bass  consider to be inhumane  and not conclusive (de la Rosa et al., 2021) . Therefore, there is an urg ent need to develop and evaluat e stunning/slaughter methods  that will ensure immediate loss of brain function, insensibility to pain and maintenance of flesh quality. The aim of the study was to evaluate the impact of different stunning methods prior to slaughter on the onset of rigor mortis, muscle pH and stress indicators in European sea bass .

Materials and Methods

European seabass (Dicentrarchus labrax) ranging in weight from 250 to 300 grams were used  to evaluate the effect of three  different stunning methods:  chemical (Group Benzocaine), electronarcosis ( Group E/A: electrical stunning, 1.5 V/cm), and thermonarcosis ( Group Ice Slurry: immersion in ice-slurry without prior anaesthetization). Following crowding, all fish were  captured by net and  slaughtered by immersion in ice-slurry.  Capture of fish by hook and line and immediate slaughter by pithing (ikijime), was used as control (Group Ikigun). M uscle pH and r igor m ortis were performed at  regular intervals between 0- and 4-hours post-mortem. Blood samples were taken to determine haematological (haematocrit), biochemical (g lucose, lactate , osmolality) and hormonal indicators (cortisol).  All data are expressed as means with the standard error of the means (SEM, n = 10 per group). Data analyses were based on ANOVA or Duncan’s multiple range test and significance ascribed to differences at the 0.05 level.



 Development of humane stunning/slaughter methods for farmed Mediterranean fish species is of high priority . E/A has shown a  great  potential as an alternative stunning method  in European sea bass  (Zampacavallo et al., 2015). Our results show  that handling stress prior to stunning significantly enhances the stress response and has a negative impact on quality indicators (RI% and muscle pH). Electrical stunning delays the time needed to reach full rigor mortis and maintain muscle pH in comparable levels with those obtained in sunning/slaughter fish in ice-slurry. Chemical anaesthesia is also stressful for the fish and affects negatively flesh quality. Finally, the study confirmed  that pithing ,  used by experienced staff, does not evoke an increase in stress indicators and ensures rapid insensibility.


de la Rosa I, Castro PL, Ginés R. Twenty Years of Research in Seabass and Seabream Welfare during Slaughter. Animals . 2021; 11(8):2164.

 Håstein T. OIE I nvolvement in A quatic A nimal W elfare: T he N eed for D evelopment of G uidelines B ased on W elfare for F arming, T ransport and S laughter P urposes in A quatic animals. Dev Biol (Basel). 2007; 129:149-61. PMID: 18306528.

Zampacavallo G, Parisi G, Mecatti M, Lupi P, Giorgi G, Poli BM. Evaluation of Different Methods of Sunning/Killing Sea Bass (Dicentrarchus labrax) by Tissue Stress/Quality Indicators. J Food Sci Technol. 2015 May;52(5):2585-97. doi: 10.1007/s13197-014-1324-8. Epub 2014 Apr 8. PMID: 25892757; PMCID: PMC4397339.


 Research funded by the European Maritime and Fisheries Fund – Operational Programme for Greece (2014 - 2020) .  Project Code:  MIS 5010690.