We show that larger values of pathogen mobility imply more severe epidemics, as the number of infections increases, and shorter timescales to extinction. Specifically, the effects of parasite mobility into the epidemic threshold and the temporal progression of the epidemic are assessed. We investigate the impact of spatial disease transmission through extensive numerical simulations and theoretical analysis. In this work, we develop a spatially explicit individual-based model to study disease transmission by waterborne parasites in sessile marine populations. However, in realistic scenarios epidemic transmission is conditioned by the spatial distribution of hosts and the parasites' mobility patterns, calling for an explicit description of space.

Compartmental models of epidemic transmission in marine sessile organisms, available only recently, are based on non-spatial descriptions in which space is homogenized and parasite mobility is not explicitly accounted for. These studies demonstrate that life history traits and the ability to adapt allow diverse parasite taxa to persist in isolated, ephemeral environments.Įmerging marine infectious diseases pose a substantial threat to marine ecosystems and the conservation of their biodiversity. Parasites that reduce host reproduction reached higher densities than parasites that cause mortality across all disturbance frequencies explored, and disturbance facilitated the evolution of more virulent parasites. Finally, I use a computational model to investigate how different parasite strategies (colonization capability and impact on hosts) contribute to parasite success under a range of disturbance conditions in island habitats. All life stages of the trematode life cyclewere discovered in vent fauna and several taxawere traced across multiple life stages via morphology and genetics. To explore this further, I investigate the three-host life cycles of trematodes at vents, whichwas the most diverse and abundant parasite taxon. Parasites with indirect (multi-host) life cycles were relatively diverse in the disturbed environment, which contradicts expectation based on theory. Overall, parasite diversity within host species was not significantly lower at vents, but the vent community had many fewer parasite species because there are fewvertebrate predator species (fish). Second, I compare parasite diversity at isolated, disturbed vents to marine ecosystems that are similarly isolated but undisturbed (atoll sandflat) and both well connected and undisturbed (kelp forest). First, I analyze recovery in the vent community for 11 years after a catastrophic eruption in 2006 to test successional hypotheses in a new setting with distinct fauna and a chemosynthesis-based food web. I focus on an island-like, frequently disturbed habitat, deep sea hydrothermal vents at 9★0’N on the East Pacific Rise, to explore the boundaries of parasite persistence in an extreme environment. In this thesis, I investigate habitat isolation and disturbance as drivers of parasite diversity, with an emphasis on parasite life history strategies related to colonization and persistence. For their reliance on host species, parasites are theorized to be particularly sensitive to disturbances that alter host diversity and abundance, especially in isolated habitats, which present challenges to introduction and establishment. Parasites are taxonomically and functionally diverse members of biological communities, and can play key roles in species interactions, community structure, and ecosystem functioning.

Stone island prismatica field