1. Stress and welfare in teleost fish
Dr. Neil Ruane
Marine Institute

2. Awareness of Fish Welfare

3. Awareness of Fish Welfare
Directive 98/58/EC – protection of animals kept for farming purposes.
EC A strategy for the sustainable development of European aquaculture. Commission of the European Communities COM (2002) 511 final, 26 pp.
“promotion of animal health and welfare as one of the three main objectives for the sustainable development of European aquaculture”
ec.europa.eu/food/animal/welfare/index_en.htm
Council of Europe – European Convention on the protection of animals kept for farming purposes: Recommendations for farmed fish (06/2006)
In 2008 the World Organisation for Animal Health (OIE) adopted guiding principles for fish welfare

4. Awareness of Fish Welfare
European Food Safety Authority – Animal Health & Welfare Panel: risk assessment of the welfare of 6 species (salmon, trout, sea bream, sea bass, eel, carp) – basis for future legislation?
In 2009 the AHAW panel adopted an opinion on the general approach to fish welfare and produced documents on stunning and killing methods for 7 species (tuna, carp, salmon, trout, sea bream, sea bass, eel and turbot).

5. Concept of fish welfare
Who cares?
- Producers: responsibility; image; CoP’s; profitability
- Processors: flesh quality; reputation
- Scientists: research opportunity; funding; obligation
- Welfarists: genuine concern (RSPCA; Freedom Foods); PR
- Consumers/Retailers: consumer perception; education; sales
Animal welfare refers to the quality of life or well-being
applied to sentient beings (self awareness, experience pain, suffering)
controversial area in fish biology
duty of care to the animals

6. Dangers of anthropomorphic explanations
Awareness in fish
Watching other fish fighting increased androgen levels in spectator fish
Androgens – sex hormones; social status; agressiveness
Concious or reflex?
Dangers of anthropomorphic explanations

7. Whether fish are sentient or not, the exposure of fish to stressors/poor conditions should be avoided or kept to a minimum

8. Interspecific competition
On-farm Stressors
Water Characteristics
Culture procedures
Chemical components
Temperature
Salinity O2
Hardness pH
Handling
Confinement
Stocking density
Air exposure
Vaccination
Culture system
Behavioural Interactions
Interspecific competition
Social dominance
Territoriality

9. Welfare indicator: 1o stress response
Hypothalamus
Sympathetic
nerves
CRH
Pituitary
ACTH
Head kidney
Chromaffin cells Interrenal cells
Catecholamines
Cortisol
MANY SITES OF ACTION

10. Interrenal cells in carp head-kidney

11. Welfare indicator: 2o & 3o responses
Secondary responses:
- energy mobilisation (increased glucose, fatty acids)
- changes in the immune system (reduction in circulating lymphocytes)
- ion (Na+, Cl-) levels change in the blood
Tertiary responses:
- reduced growth/poor appetite
- immune suppression/disease outbreak
- impaired reproduction

12. Link between stress and disease9 23 21
Winter disease - Gilthead seabream
(Sparus auratus) 8 7 19 6 17
% feeding & % mortality 5 15
Temperature 0C & Cortisol ng/ml 4 13 3 11 2 9 1 7 5
Sep
Oct
Nov.
Dec
Jan
Feb
Mar
Apr
May
Mortality
Feeding
Temp
Cortisol
140
warm
cold1
cold 2
120
100 * * * 80 * * * * * *
% respect to warm period 60 40 20
agglutination
ach50
lysozyme
lymphocytes
NBT
Tort et al., Comparative Biochemistry & Physiology A 120:

13. Link between stress and disease
The fact that studies have shown a good innate antibody response in fish provides a good possibility for vaccine development
Fig. 2. Cumulative mortality of the cohabitees (Atlantic salmon) after IPNV challenge from day 0 to 47 post-challenge, shown as mean±SE. Description: ▴: non-challenged fish and represents both the normoxic and hyperoxic group, ●: Challenged, hyperoxygenated group, ■: Challenged, normoxic group. Ndead=110.
Fridell et al., Aquaculture 270: 23-35

14. Link between stress and growth
Daily exposure to stress reduces growth in juvenile carp
The fact that studies have shown a good innate antibody response in fish provides a good possibility for vaccine development
Ruane et al., General Comparative Endocrinology 150:

15. Stress/welfare on the farm - transport
Many disease outbreaks occur during the first months of transfer to sea
- stress of transportation
- prolonged stress leads to immunosuppression
- smolts are more sensitive to stress compared with parr
Carey & McCormick, Aquaculture 168:
Commercial well boat transport of Atlantic salmon
- loading more stressful than unloading
- stressful transport linked with high mortalities
- well boats can play a role in recovery of the fish
Iversen et al., Aquaculture 243:

16. Stress/welfare on the farm - noise
Effects of environmental noise initially focussed on sonar, pile driving, seismic air guns -
Now looking at aquaculture – chronic exposure to noise
Fish have highly developed sensory systems
- hearing: combination of the lateral line and ear
Hearing specialists – cyprinids (still water more quiet)
Hearing generalists – salmonids (fast flowing rivers more noise)
Talk outline: Review of PD followed by programme outline. Final part is the role of stress.

17. Stress/welfare on the farm - noise
Effects of noise:
Induces a stress response in exposed fish
Can induce temporary hearing loss
Specialists more sensitive
Fish can recover over time
Smith et al., Journal of Experimental Biology 207:

18. Monitoring Welfare/Stress on farms - OWI
Many methods of monitoring stress are a stressor in themselves
There is a need for non-invasive welfare/stress monitoring
- Operational Welfare Indicators (OWI)
- observe behaviour, remote sampling
- measurement of cortisol, or other stress-activated compounds, in urine, faeces or water
Ruane & Komen, Aquaculture 218:

19. Monitoring Welfare/Stress on farms - OWI
Operational Welfare Indicators – factors which can be corrected
Direct OWI’s – relate to the fish
Indirect OWI’s – relate to the system
Practical OWI’s:
Farm conditions
Water quality
Behaviour/appearance
Nutrition/feeding
Health
Serology/physiology

20. EU projects on fish welfare
AQUAFIRST – selective breeding to improve disease and stress resistance in fish and shellfish
FASTFISH – on farm assessment of stress levels in fish
FINE FISH – reduction of malformations of juvenile fish in hatcheries
COST 867 – a network on fish welfare in European aquaculture
BENEFISH – benefits and costs of fish welfare in European aquaculture
Compared with other diseases PD results in much higher losses