A Kettle of Fish: A Review of the Scientific Literature for Evidence of Fish Sentience.

Fish are traded, caught, farmed, and killed in their trillions every year around the world, yet their welfare is often neglected and their sentience regularly disregarded. In this review, we have sought to (1) catalogue the extent to which fish sentience has featured over the past 31 years in the scientific literature and (2) discuss the importance of fish sentience in relation to their commercial uses. We searched the journal database Science Direct using 42 keywords that describe traits or elements of sentience to find articles that were referring to or exploring fish sentience. Our review returned 470 results for fish sentience in 142 different species and subspecies of fish, and featured 19 different sentience keywords. The top four keywords were; 'stress' (psychological) ( = 216, 45.9% of total results), 'anxiety' ( = 144, 30.6%), 'fear' ( = 46, 9.7%), and 'pain' ( = 27, 5.7%). Our findings highlight an abundance of evidence for fish sentience in the published scientific literature. We conclude that legislation governing the treatment of fish and attitudes towards their welfare require scrutiny so that their welfare can be safeguarded across the globe.