Physiological response of temperature shocks in turbot and sole

ABSTRACT

In the present study, selected temperature drops were examined to investigate the effects of live chilling on stress and welfare in turbot and sole. This study demonstrated that rapid temperature drops from 11°C–12°C and 18°C–18.7°C to 4°C–0°C in turbot resulted in higher blood sodium and potassium at 0°C (164 mmol l⁻¹, 4.4 mmol ⁻¹) compared to 4°C (153 mmol l⁻¹, 3.1 mmol ⁻¹), indicating osmoregulatory disturbance. A rapid temperature drop from 18°C to 0°C in Senegal sole also resulted in higher blood sodium and potassium at 0°C (164 mmol l⁻¹, 4.8 mmol ⁻¹) compared to the control group at 18°C (157 mmol l⁻¹, 3.2 mmol ⁻¹). Based on present findings, we conclude that immersion in ice water will have a negative effect on the animal osmoregulatory capacity, and we recommend that turbot and sole are stunned before slaughter.

KEYWORDS:

• Hypothermia
• live chilling
• temperature
• sole
• turbot

Acknowledgments

We would like to thank the involved project partners: Seafarm B.V in The Netherlands, Seaside AS in Norway, and Aquacria Piscicolas in Portugal. We want to thank Mr. Joachim Stoss for providing fish for the trials in Norway.

Compliance with ethical standards

The work in the Netherlands (turbot—trial 1) and Portugal (trial on sole) were done in accordance with current European and Dutch regulations on the use of animals for scientific purposes (approved by the Animal Care and Use Committee). The Norwegian experiment (turbot—trial 2) described has been approved by the local responsible laboratory animal science specialist under the surveillance of the Norwegian Animal Research Authority (NARA) and registered by the Authority.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the European Commission FP7 Research for the Benefit of SMEs [MAXIMUS, 286200]