From Land to Water: Taking Fish Welfare Seriously

Abstract

This article aims to use contemporary (terrestrial) animal welfare science as a lens to evaluate the state of knowledge concerning welfare in fish species, focusing on farmed fishes. We take advantage of the vast expertise—including previous pitfalls and accomplishments—in the investigation of welfare in terrestrial vertebrates, borrowing questions and methodologies from terrestrial animal welfare science in order to (1) better understand the challenges and opportunities in the study of welfare in fish species, and (2) propose strategies for filling knowledge gaps.

Looking beyond the Shoal: Fish Welfare as an Individual Attribute

“…Given the general consensus among animal welfare scientists that welfare is, first and foremost, an attribute of an individual, [ 1 , 11 , 12 ] not a flock, herd, or shoal, some argue that welfare should thus be measured primarily at the level of the individual [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. For the sake of clarity and building on previous definitions [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ], we regard welfare as the emotional experience of an individual that results from that fish’s interactions with her environment over time, existing on a continuum from negative to positive.…”

“…Currently, fish welfare scientists recognize that welfare must go beyond simply mitigating health problems to include provision of environments designed to improve other aspects of welfare [ 33 , 34 , 35 , 36 , 37 , 38 , 39 ], with some even advocating for provision of environments conducive to positive welfare [ 25 ]. Positive welfare is a concept that is still developing in the fish welfare discipline, but in short, goes beyond the Five Freedoms to provision of experiences where agency, choice, control, cognitive stimulation, meaning, and challenge are crucial dimensions to consider [ 21 ]. Given the huge number and diversity of fish species being farmed, it is no surprise that this concept has only recently been applied to fishes [ 25 ].…”

“…Given the huge number and diversity of fish species being farmed, it is no surprise that this concept has only recently been applied to fishes [ 25 ]. The study of what fish need and want in these complex respects, as species, groups or individuals, is still in its infancy [ 21 ].…”

Waves and currents decrease the available space in a salmon cage

“…In addition to increasing demand for salmon driving industry to innovate, there is also an increased awareness of fish welfare considerations [30,31]. This means that there is growing consumer pressure for not only environmental certifications such as ASC (Aquaculture Stewardship Council) [32], but also for assurances that the farms can deliver a minimum welfare standard, such as the RSPCA assured scheme [33].…”

Tracking and Analysis of the Movement Behavior of European Seabass (Dicentrarchus labrax) in Aquaculture Systems

“…For example, underfeeding could result in aggressive behaviors, and excess feeding results in behaviors related to unfavorable environments, particularly in closed systems, i.e., increased nitrogen or decreased oxygen levels (Magnuson, 1962;Benhaïm et al, 2012;Bergqvist and Gunnarsson, 2013;Li et al, 2020b). Other types of behavioral responses could be linked to husbandry practices, such as the presence/absence of people on the rearing sites (Sánchez-Suárez et al, 2020;Seibel et al, 2020). A set of easily observed measurements known as operational welfare indicators (OWIs) were recently adopted to monitor fish behavior and welfare in a non-destructive form (Noble et al, 2018), of which, swimming behavior is of particular importance for all aquaculture systems.…”