The Influence of Individual Physiology on Group Behaviour in Fish Schools

The behaviour of schooling fishes is one of the most fascinating phenomena in the animal kingdom, and images of shimmering fish schools have become emblematic of the aquatic world. In addition to being aesthetically captivating, schooling behaviour is also of great biological importance, playing a role in the foraging and predator-avoidance behaviour of multiple species in both freshwater and marine ecosystems. The fluid, synchronous movement of fish schools has long been studied, but it is still unknown how the behaviour of individual fish within the school influences the performance of the group as a whole. Understanding the links between individual and group performance is important since future disturbances to aquatic environments - in response to factors such as pollution or climate change, for instance - may cause changes in the physiology and behaviour of individual fish, and by extension, entire fish schools. The effect of environmental change on animals living in groups has been mostly overlooked, and fish schools are perfectly suited for studying this important aspect of biodiversity. This project will examine these issues by investigating how physiological differences between individual fish may affect their behaviour within a school, and in turn, how these individuals affect the behaviour of the entire school in response to environmental stressors such as increased temperature or decreased oxygen availability. To achieve these goals, this Fellowship will include several laboratory-based studies, and, by using Northern Europe's largest public aquarium (located in Denmark), will also incorporate the first ever scientific observations of individual behaviours in a school containing thousands of fish. Fish schools are ideal for studying the interaction between physiology and behaviour in animals, a link which has rarely been demonstrated directly. As such, any advances in this subject are likely to result in a range of questions for future research in both ecophysiology and behavioural ecology.

The main beneficiaries of this project will be the general public and scientists working in diverse disciplines. The study of animal group behaviour is a rapidly growing field, yielding insights into numerous subject areas with applications in human society including social networks, information transmission and communication, group decision making, disease transmission, and human crowd control. It should also be noted that the study of the role of individual physiology in fish schools could have applications for the commercial fishing industry. Some types of fishing gear, such as nets used for trawling, capture portions of much larger fish schools, and so it would be useful to understand the potential selective impacts of such processes. In addition, some gear types are specifically designed to allow some individuals to escape (e.g. fish of a certain size). If the ability to escape such gear is also related to swimming ability, then individuals could be selected based on intrinsic physiological traits such as aerobic capacity. The behaviour of economically important species could also change in response to changing environmental temperatures or levels of oxygen availability, affecting the size, shape, or geographical distribution of schools and thus affecting their ability to be harvested by commercial fisheries. The proposed Fellowship will allow a greater understanding of the physiological variation present in fish schools, and the effects of this variability on environmental tolerances. The general public is inherently fascinated with fish schools due to their spectacular appearance and perceived capacity for "group intelligence" due to the synchronous movements of school-members. The public will be exposed to the research of this Fellowship via work done at the Nordsoen Oceanarium Public Aquarium in Hirtshals, Denmark, where there will be a public display describing the purpose and methods behind the project. This display will later be adapted to include results of the work and will be incorporated into the Hunterian Zoology Museum at the University of Glasgow.