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dc.contributor.advisorDuffy, Meghan A.
dc.contributor.advisorHay, Mark E.
dc.contributor.authorPenczykowski, Rachel M.
dc.date.accessioned2014-01-13T16:51:12Z
dc.date.available2014-01-13T16:51:12Z
dc.date.created2013-12
dc.date.issued2013-11-18
dc.date.submittedDecember 2013
dc.identifier.urihttp://hdl.handle.net/1853/50368
dc.description.abstractI investigated effects of environmental change on disease, and effects of disease on ecosystems, using a freshwater zooplankton host and its fungal parasite. This research involved lake surveys, manipulative experiments, and mathematical models. My results indicate that ecosystem characteristics such as habitat structure, nutrient availability, and quality of a host’s resources (here, phytoplankton) can affect the spread of disease. For example, a survey of epidemics in lakes revealed direct and indirect links between habitat structure and epidemic size, where indirect connections were mediated by non-host species. Then, in a mesocosm experiment in a lake, manipulations of habitat structure and nutrient availability interactively affected the spread of disease, and nutrient enrichment increased densities of infected hosts. In a separate laboratory experiment, poor quality resources were shown to decrease parasite transmission rate by altering host foraging behavior. My experimental results also suggest that disease can affect ecosystems through effects on host densities and host traits. In the mesocosm experiment, the parasite indirectly increased abundance of algal resources by decreasing densities of the zooplankton host. Disease in the experimental zooplankton populations also impacted nutrient stoichiometry of algae, which could entail a parasite-mediated shift in food quality for grazers such as the host. Additionally, I showed that infection dramatically reduces host feeding rate, and used a dynamic epidemiological model to illustrate how this parasite-mediated trait change could affect densities of resources and hosts, as well as the spread of disease. I discuss the implications of these ecosystem–disease interactions in light of ongoing changes to habitat and nutrient regimes in freshwater ecosystems.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectDaphnia
dc.subjectEpidemiology
dc.subjectEutrophication
dc.subjectForaging behavior
dc.subjectFungal pathogen
dc.subjectHabitat structure
dc.subjectHost-parasite
dc.subjectNutrient enrichment
dc.subjectZooplankton
dc.subject.lcshEpidemiology Research
dc.subject.lcshMarine ecosystem health
dc.subject.lcshMarine ecology
dc.subject.lcshPlankton
dc.subject.lcshFreshwater plankton
dc.titleInteractions between ecosystems and disease in the plankton of freshwater lakes
dc.typeDissertation
dc.description.degreePh.D.
dc.contributor.departmentBiology
thesis.degree.levelDoctoral
dc.contributor.committeeMemberHall, Spencer R.
dc.contributor.committeeMemberMontoya, Joseph P.
dc.contributor.committeeMemberSnell, Terry W.
dc.contributor.committeeMemberWeitz, Joshua S.
dc.date.updated2014-01-13T16:51:12Z


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