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the other hand, are most commonly used indicators
of fish welfare. Generally, signs of homeostasis disruption expressed as morphological and swimming abnormalities, outbreak of (parasitic) diseases, loss of condition, etc., are generally suggestive of poor fish welfare. Hematological, biochemical and non-specific immune parameters have also been assessed to identify poor welfare of fish through starving 3. Blood hematocrit and hemoglobin, plasmatic cholesterol, cortisol, aspartate aminotransferase, alanine aminotransferase, glucose, plasma total protein concentrations and plasma lysozyme concentrations have been studied to find correlations between these conditions in fish and poor welfare. However, the results showed adaptation of the metabolic profile of starved fish which is not suggestive of alarm-stress response. The most common stress indicator, the glucocorticoid hormone cortisol, has been proved to reach increased levels in stressed animals, leading, assumingly, to stimulation of protein catabolism, lipolysis and gluconeogenesis. Although viewed as an important welfare impairment indicator in fish, cortisol has little value if fish welfare is regarded from behavioral perspective and on single time point measurements,
as it is considered rather a natural, adaptive response
to environmental conditions and husbandry practices. Cortisol releases cannot be predictable, requiring a number of variables to be accounted for, such as
diurnal and seasonal variations, as well as genetic and environmental factors. Fish studies indicate as areas of clarification for the use of cortisol as fish welfare indicator, separation of chronic stress from acclimatization and identification of the relation between feelings, cortisol and behavior of fish 4,5.
Scientific studies to assess fish welfare are continually evolving. The challenge includes the great diversity of fish species and production systems, while relevant scientific data in this field are still missing. In the European Union, the Council Directive 98/58/EC lays down minimum standards of protection for animal species bred or
kept for farming purposes, including fish. In 2005, the Council of Europe adopted a recommendation on the welfare of farmed fish. Three years later, the OIE adopted guiding principles for fish welfare. The EFSA Panel on animal health and welfare (AHAW) adopted in 2009
an overall approach regarding fish welfare, including welfare aspects of stunning and killing methods for seven species of farmed fish.
All aspects relevant to fish welfare will be systematically discussed during the presentation.
1. Pringle L (1989) The Animal Rights Controversy.Harcout Brace Jovanovich Publishers, NY, USA
2. Singer P (1975) Animal Liberation: A New Ethics in Our Treatment of Animals, Random House, NY, USA
3. Kim JH, Jeong HM, Jun JC, Kim TI (2014) Changes in Hematological, Biochemical and Non-specific Immune Parameters of Olive Flounder, Paralichthys olivaceus, Following Starvation. Asian-Australas J Anim Sci. 2014 Sep; 27(9): 1360–1367. doi: 10.5713/ajas.2014.14110
4. Ellis T, Yildiz HY, López-Olmeda J, Spedicato MT, Tort L, Øverli Ø, Martins CI (2012) Cortisol and finfish welfare. Fish Physiol Biochem. 2012 Feb;38(1):163-88. doi: 10.1007/s10695-011-9568-y. Epub 2011 Nov 24
5. Gräns A, Niklasson L, Sandblom E, Sundell K, Algers B, Berg C, Lundh T, Axelsson M, Sundh H, Kiessling A (2016) Stunning Fish with CO2 or Electricity: Contradictory results on behavioral and physiological stress responses. Cambridge University Press Animal. 2016 Feb; 10(2): 294–301. Published online 2015 May 11. doi: 10.1017/S1751731115000750
An Urban Experience

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