DescriptionThe structure of free-living trophic interactions, detailed as food webs, describes potential parasite transmission routes and is likely to provide considerable insight into parasite community dynamics. Despite this framework, a lack of empirical data has largely restricted food web analyses to addressing fundamental questions asking how parasites ‘fit’ into food webs and food web theory. The purpose of this dissertation was to determine how the complex dynamics in the host food web affects the establishment and persistence of parasites. This study focused on helminth parasites with obligate bird, fish and macroinvertebrate hosts that are intimately tied to trophic interactions in food webs from salt marshes throughout the New York-New Jersey Harbor estuary complex. This study was done in four salt marshes, one unrestored and three that were restored at 0, 10 and 20 years previously, and which reflected a gradient in host diversity. There was no relationship between the diversity of the free-living community and the diversity of the parasite community. However, there was a strong correlation between the trophic structure of the host community and complex life cycle parasite presence. The topology of each salt marsh food web was highly nested with clusters of generalists forming distinct core/periphery structure. Two thirds of all parasite stages were constrained to these core species and their physical location in the food web. Community matrices constructed with randomly determined interaction coefficients to assess community stability confirmed a correlation between system stability and parasite species richness in our sentinel fish species. These data suggest that core free-living species within the food web represent stable trophic relationships that allow for the persistence of complex parasite life cycles. Further, these data suggest a prominent role for clusters of free-living trophic interactions in the establishment of trophically transmitted parasites and the potential for the evolution of complex life cycles.
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
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