DISSERTATION RESEARCH: Effects of community structure on host-pathogen dynamics of Batrachochytrium dendrobatidis

Oregon State University, Corvallis OR

Investigators

Abstract

The recent emergence of infectious diseases in wildlife has brought increased attention to their role in current population declines and species extinctions. One such disease is the chytrid fungus, which infects amphibians globally, is often lethal to the host, and is associated with species extinctions. Recent research has found that zooplankton can consume the infective stage of this pathogen, but it is unknown whether this is ecologically important for protecting amphibian populations from infection. This project will combine laboratory experiments with surveys of lakes in the Sierra Nevada Mountains to answer the question of how zooplankton affects the dynamics of chytrid infection in frog species. Experiments will investigate whether consumption of the chytrid fungus by zooplankton reduces infection levels for two different life stages of frog species under controlled environmental conditions. These results will be compared to data from a field survey of the chydrid fungus in the natural lakes. This field study will quantify interrelationships among infection intensity of endangered mountain-yellow legged frog hosts, zooplankton, and the presence of predatory fish. Understanding the causes for losses in biodiversity is a pressing challenge in conservation biology. This research will contribute to urgently needed control measures for the emerging infectious chytrid pathogen responsible for worldwide population declines and extinctions of amphibians. Several undergraduate students will be given research training in experimental and field ecology. This project will also develop teaching modules on emerging disease and conservation issues that will be presented to groups of middle and high school students from traditionally underrepresented backgrounds visiting Oregon State University through pre-college programs.