Predator-prey interactions in aquatic communities

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One of the most important interactions within an ecosystem is predation, as it is the mechanism by which energy and nutrients flow through an ecosystem. A well adapted predator must be successful at capturing its prey; well adapted prey must be successful at escaping this fate. Because such interactions are so important, both predators and prey have evolved a diverse array of strategies and tactics to tilt the outcome of these interactions in their favour. The goal of my proposed research program is determine how predator-prey interactions are affected by a changing environment, and how such information may then be applied to restoring threatened populations. I will investigate how changing temperatures may impact the balance between predator and prey. For all freshwater aquatic ecosystems within Canada, the energetic requirements of fish are determined by their environment. What happens if this temperature increases? To answer this question, I will first directly measure the relation for different species within an ecosystem. My expectation is that both predator and prey will likely need more food in a warmer environment. For the ecosystem, the implication is that warmer temperatures will require animals to more often risk death in order to obtain food. I will also explore how changing sources of information will impact predator-prey interactions. Both are known to use both visual and chemical senses and I want to know how use of these different senses may confer an advantage within a dynamic environment. Understanding this process may make it possible to predict the consequences of changes in the aquatic ecosystem associated with changes in water clarity - a common consequence of man-made changes in the environment. Finally, I will also explore whether consistent variation in the growth rates of fishes within a species is a consequence of genetic variation, or an adaptation to deal with environments that vary in the level of predation risk. If the latter, I then hope to develop this idea as a tool in conserving endangered species.