Parasites and pathogens do more than just kill their hosts, they can also alter host activity level and metabolic function, which in turn influences how hosts interact with other species in the community. These trait mediated effects can have greater impacts on ecosystem function than lethal, density mediated effects, especially if the host is a keystone species. However, studies demonstrating this effect have thus far been limited, primarily because parasites have previously been viewed as a nuisance to individuals or populations rather than as important drivers of ecosystem processes.
In collaboration with other members of ISU’s faculty, my lab utilizes Iowa’s prairie potholes to understand how sublethal parasite effects on two primary consumer species: Daphnia and Ramshorn snails, Helisoma trivolvis, influence ecosystem stability. These consumers are keystone species that significantly influence the biomass of autotrophs in these systems through grazing. The parasites I plan to target, Metschnikowa bicuspidate in daphnia and trematodes in snails, have been demonstrated to alter the grazing rate of their hosts, suggesting that these parasites could have profound effects on these ecosystems.
Aquatic Disease Ecology in a Changing World 