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Stress and welfare in teleost fish

Dr. Neil Ruane Marine Institute

Awareness of Fish Welfare

Awareness of Fish Welfare Directive 98/58/EC – protection of animals kept for farming purposes. EC. 2002. 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) www.coe.int

In 2008 the World Organisation for Animal Health (OIE) adopted guiding principles for fish welfare www.oie.int

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? www.efsa.europa.eu

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).

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

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

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

On-farm Stressors

Water Characteristics Chemical components Temperature Salinity O2 Hardness pH

Culture procedures Handling Confinement Stocking density Air exposure Vaccination Culture system

Behavioural Interactions Interspecific competition Social dominance Territoriality

Welfare indicator: 1o stress response Hypothalamus Sympathetic nerves

CRH

Pituitary ACTH Head kidney Chromaffin cells

Interrenal cells

Catecholamines

Cortisol

MANY SITES OF ACTION

Interrenal cells in carp head-kidney

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

23 21 19 17 15 13 11 9 7 5 Sep Oct Nov. Dec Jan Feb Mar Apr May Mortality

Feeding

Temp

warm

140

% respect to warm period

(Sparus auratus)

9 8 7 6 5 4 3 2 1 0

cold1

Temperature 0C & Cortisol ng/ml

Winter disease - Gilthead seabream

% feeding & % mortality

Link between stress and disease

Cortisol

cold 2

120 100 80

**

* *

**

*

* *

60 40 20 0 agglutination ach50

lysozyme lymphocytes

NBT

Tort et al., 1998. Comparative Biochemistry & Physiology A 120: 175-179

Link between stress and disease

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., 2007. Aquaculture 270: 23-35

Link between stress and growth

Daily exposure to stress reduces growth in juvenile carp

Ruane et al., 2007. General Comparative Endocrinology 150: 473-479

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, 1998. Aquaculture 168: 237-253

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., 2005. Aquaculture 243: 373-382

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)

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., 2004. Journal of Experimental Biology 207: 427-435

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, 2003. Aquaculture 218:685-693.

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

EU projects on fish welfare AQUAFIRST – selective breeding to improve disease and stress resistance in fish and shellfish http://aquafirst.vitamib.com FASTFISH – on farm assessment of stress levels in fish http://fastfish.imr.no FINE FISH – reduction of malformations of juvenile fish in hatcheries http://www.finefish.info COST 867 – a network on fish welfare in European aquaculture http://www.fishwelfare.com

BENEFISH – benefits and costs of fish welfare in European aquaculture http://www.benefish.eu