Fish welfare

Question 1

what is pain?

Answer 1

Nociception - involves only detection of a noxious or tissue damaging stimulus - followed by a reflex
pain perception involved non - reflexive behaviour by animal adversely affected by a potentially painful stimulus (Sneddon 2003) may involve learning from experience

Question 2

what evidence did rose (2002) give that fish dont feel pain?

Answer 2

concluded that appareant suffering was due to anthromorphising
says that fish display nociceptive reactions (detection of stimulus + reflex)
ARGUES THAT THIS SHOULDNT BE CONFUSED WITH TRUE PAIN EXPERIENCE

Question 3

what was Rose’s logic?

Answer 3

1. That awareness of pain requires consciousness
2. Consciousness resides in complex neocortex of the cerebrum
3. Only mammals have a neocortex
4. Therefore fish cannot experience pain

Question 4

what physiological evidence is there that fish do feel pain in Rainbow trout?

Answer 4

Rainbow trout have complete “neuro-apparatus” and wiring to feel pain.
Some of their nociceptors were 6 x more sensitive than similar skin receptors in humans.

Question 5

what experiment by sneddon (2003) gave evidence that feel do feel pain?

Answer 5

Trout were injected in the upper and lower lips with acetic acid - showed behavioural responses indicative of pain perception
Increased opercular beat rate
Fish also rocked while resting and didnt eat, some fish rubbed snouts of side of tank.
TIME LAG BETWEEN INJECTINVAND PERFORMANCE OF PAIN COPING TACTICS - RESPONSES WERE NOT REFLEXES

So fish do feel pain

Question 6

what problems may arise from catch and release fishing?

Answer 6

individual cutthroat trout in the Yellowstone river caught on average 9.7 times in the summer fishing season
However, mortality from hooking is usually low (smaller than 5%).

Question 7

what are sub-lethal effects of Catch and release?

Answer 7

altered social behaviour + impaired reproduction and growth (Muoneke and childress 1994)