Data from: Salmon behavioural response to robots in an aquaculture sea cage

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.