Salmon behavioural response to robots in an aquaculture sea cage

Abstract

Animal–robot studies can inform us about animal behaviour and inspire advances in agriculture, environmental monitoring and animal health and welfare. Currently, experimental results on how fish are affected by the presence of underwater robots are largely limited to laboratory environments with few individuals and a focus on model species. Laboratory studies provide valuable insight, but their results are not necessarily generalizable to larger scales such as marine aquaculture. This paper examines the effects of underwater robots and a human diver in a large fish aggregation within a Norwegian aquaculture facility, with the explicit purpose to improve the use of underwater robots for fish observations. We observed aquaculture salmon's reaction to the flipper-propelled robot U-CAT in a sea cage with 188 000 individuals. A significant difference in fish behaviour was found using U-CAT when compared to a thruster-driven underwater robot, Argus Mini and a human diver. Specifically, salmon were more likely to swim closer to U-CAT at a lower tailbeat frequency. Fish reactions were not significantly different when considering motor noise or when U-CAT's colour was changed from yellow to silver. No difference was observed in the distance or tailbeat frequency as a response to thruster or flipper motion, when actuated and passively floating robots were compared. These results offer insight into how large aggregations of aquaculture salmon respond to underwater robots. Furthermore, the proposed underwater video processing workflow to assess fish's response to underwater robots is simple and reproducible. This work provides a practical method to study fish–robot interactions, which can lead to improved underwater robot designs to provide more affordable, scalable and effective solutions.

Non-Linear Analyses of Fish Behaviours in Response to Aquatic Environmental Pollutants—A Review

“…Roughly, they can be divided into those based on the analysis of sounds/acoustics [18,19], some of which produce images (i.e., [20]) and the more common methods based on the analysis of video images. Both the sensors themselves and their deployment may influence fish behaviour; for example, acoustic telemetry requires the invasive process of tagging a certain number of fish [19,21], the sonar may influence the fishes' hearing [22], and the use of recording instruments handled by human or robots have been shown to influence their behaviour [23,24]. Fixed sensors (fixed cameras and passive hydroacoustic sensing) interfere least with the behaviour of the fish.…”

Compatibilities of Cyprinus carpio with Varied Colors of Robotic Fish

“…As an important tool to study animal behavior, in recent years, bionic robots have been widely used in the study of animal social behavior because of their controllability and the repeatability of experiments [31][32][33][34][35][36][37]. Compared with a traditional mobile platform and axial propeller underwater robots, bionic underwater robots have the advantages of low noise and environmental friendliness [38][39][40][41]. Bionic robots can be used in animal behavior experiments to reduce the interference of the environment and improve the accuracy of the experiment [42].…”

Towards Fish Welfare in the Presence of Robots: Zebrafish Case

“…However, conventional underwater robots used to date can, in many cases, have an impact on the environment, as well as being intrusive and stressful to marine life, due to their aesthetic and/or mechanical characteristics [7,8].…”