TPOINT · Parasitism and climate change: A tipping point for blue mussel populations?

Global warming constitutes an urgent challenge to humanity, and predicting the far-reaching impacts on ecosystems remains a major scientific task. Blue mussels (Mytilus edulis) are a dominant species along European coastlines, where they play central ecological roles and are of high economic importance. Increases in ocean temperature will not only affect mussels directly but also increase transmission dynamics of their parasites. Together, the effects of a rise in temperature and parasitism will result in increased pressure on M. edulis and their ability to perform vital ecosystem services. How this will impact mussel populations, and ultimately the whole ecosystem, is currently unexplored and impossible to predict due to our lack of experimental data and predictive models. In a worst-case scenario, these combined stressors could lead to a tipping point for mussel populations and the presently balanced coastal ecosystem. In the project TPOINT, I will analyse the synergetic effects of temperature and trematode infections on blue mussels, ranging from individual effects to impacts on population and community structure at the ecosystem level. I will do this through a set of specifically designed mesocosm and field experiments under projected warming scenarios that will provide data for a novel predictive model of the combined parasite and climate change pressure on mussel populations. This project is the first to test these combined effects on blue mussel populations and their role as ecosystem engineers, and will provide novel insights into the ways global changes will influence species interactions and impact sensitive and complex ecological systems. The data gained from TPOINT will significantly advance our understanding of how host-parasite systems will respond to climate change and will help us predict the associated ecological impacts of such changes. This practical knowledge can support the sustainable management of ecosystems in the future.