Lambert, H., Cornish, A., Waley, D. 2024. The value of regulating stocking densities in aquaculture must not be dismissed: A reply to Saraiva et al. 2022. Frontiers in Veterinary Science 10.

We would like to rebut the argument made by Saraiva et al. (1) in their paper “Finding the “golden stocking density”: a balance between fish welfare and farmers' perspectives,” that stocking densities should not be regulated in aquaculture. In their paper, the authors make the case that although inappropriate stocking densities in aquaculture can negatively impact fish welfare, they should not be regulated for the following reasons. First, they state that stakeholders are searching for an “optimal stocking density” and that this outlook is biased from the outset. Second, they argue that conclusions regarding stocking density vary from study to study. Third, they argue that there is no functional meaning or biological need behind stocking density. Fourth, they argue that because stocking density interacts with many other welfare parameters and indicators, it should only be used as a farmer management tool, as its regulation would be unworkable and ineffective. In this paper, we dispute these arguments and provide evidence to show that stocking density can, and is already, reliably and effectively used in aquaculture, including to govern welfare and, along with other key indicators, offers a species-relevant meta-indicator and intervention tool.