Interactions between ecosystems and disease in the plankton of freshwater lakes

dc.contributor.advisor Duffy, Meghan A.
dc.contributor.advisor Hay, Mark E.
dc.contributor.author Penczykowski, Rachel M.
dc.contributor.committeeMember Hall, Spencer R.
dc.contributor.committeeMember Montoya, Joseph P.
dc.contributor.committeeMember Snell, Terry W.
dc.contributor.committeeMember Weitz, Joshua S.
dc.contributor.department Biology
dc.date.accessioned 2014-01-13T16:51:12Z
dc.date.available 2014-01-13T16:51:12Z
dc.date.created 2013-12
dc.date.issued 2013-11-18
dc.date.submitted December 2013
dc.date.updated 2014-01-13T16:51:12Z
dc.description.abstract I 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.description.degree Ph.D.
dc.format.mimetype application/pdf
dc.identifier.uri http://hdl.handle.net/1853/50368
dc.language.iso en_US
dc.publisher Georgia Institute of Technology
dc.subject Daphnia
dc.subject Epidemiology
dc.subject Eutrophication
dc.subject Foraging behavior
dc.subject Fungal pathogen
dc.subject Habitat structure
dc.subject Host-parasite
dc.subject Nutrient enrichment
dc.subject Zooplankton
dc.subject.lcsh Epidemiology Research
dc.subject.lcsh Marine ecosystem health
dc.subject.lcsh Marine ecology
dc.subject.lcsh Plankton
dc.subject.lcsh Freshwater plankton
dc.title Interactions between ecosystems and disease in the plankton of freshwater lakes
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Hay, Mark E.
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Biological Sciences
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relation.isOrgUnitOfPublication c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5
thesis.degree.level Doctoral
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