Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, that control devices in an aquaculture environment. One of the methods includes determining a particular objective for a robot that is operating in an aquaculture environment and determining one or more sensed conditions that are associated with the aquaculture environment. The particular objective is provided to an anti-fish-startling model evaluation engine that is configured to output actions, for a given objective, that accomplish the given objective while reducing a startling effect on nearby fish. Based on providing the particular objective to the anti-fish-startling model evaluation engine, one or more particular actions for accomplishing the particular objective are determined. The one or more particular actions are transmitted to another device.