We are far from understanding what individuals of the different species classified under the umbrella term “fish” need to experience good lives. The aquaculture industry has been expanding swiftly, and fishes belonging to hundreds of very different species are now farmed by the billions. Informed by terrestrial animal welfare science, this article aims to set a framework for making progress in investigating how to provide farmed fish with good welfare.

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.